If accelerating hard, there is a 2 second hesitation, whether moving or from a stop so I'm constantly modulating the throttle to eliminate hesitation. Once on this file select it and it will download to 100 percent. Seems to happen more dramatically under hard braking. Rich mixtures just don't cause stumble or hesitation, lean mixtures do, If it were me, all of these are with a warm engine 1 - Check timing, both initial and total, with vacuum advance unhooked and plugged. FiTech Fuel Injection has been supplying automotive products, specifically fuel injection products, since 2012. At most it would be a little rich. The engine still stumbles and backfires through the carb. During certain situations, the injectors can be turned off. Stumble on fast accelerationBy noexpert · 1 2. 70 Maverick Grabber, 5. Acceleration Enrichment can't be tuned until the Base Fuel Table is well tuned. The AFR at that time is about 15:1 16:1, and corrects itself quickly to 13:1. Forum Navigation. Hi there, Finally got my Chevelle out of the garage with the new engine this morning. This wetness also m. I looked at my logs, and I noticed that there is a brief dip to an AFR in the 10's between 2000-3000 RPM on WOT from idle or low RPM. Car idles fine on its own with IAC off and spark help off. To start with turn the key to the on position and then find Go EFI Tuning on the main menu and press enter. The car starts, idles and runs ok under gentle acceleration. I spent many hours on internet looking for answers to "rough idle, acceleration hesitation" problem. Jul 16, 2008 · Air/Fuel Mixture Tuning Guidelines. engine stumbles on acceleration, need help. Backfires occur in engines with severe malfunctions, such as those with diverter valve. Turbo Charged - 10 lbs. 3 hp at 6,800 rpm. A lean hesitation vs a fuel rich bog cannot always be deduced by the seat of your pants. My problem is a severe stumble on fast acceleration that does not resolve no matter how much adjustment I make to Accel Pump, or Fast Accel inputs. I added a ground wire from FITECH TB to chassis ground, made sure I have a good ground with a meter. Once in this menu scroll down to the second to last selection, it should say Default v8 T195. Then, we swapped it out for the LSXrt top, and power jumped to 703. I called the carb place that rebuilt it and they said it must be an electrical or iginition problem as a backfiring problem is 99% electircal. To start with turn the key to the on position and then find Go EFI Tuning on the main menu and press enter. Also it will run right up to 5500 if I use a slow and steady acceleration. 3) Problems Starting. It takes 5-6 revolutions to get it to light off. Oct 12, 2020 · Without hesitation and desperate for any progress, we switched it to the other notch and it fit in super snug (this was about a 90° rotation of the cap ONLY, NOT the entire unit). I have a serious stumble on hard acceleration that just doesnt seem to go away, tweeking timing. These are a basic overview of the most common setup questions. This is done by controlling the voltage to the Command Center. RPM heads, RPM intake, FiTech EFI, Comp XE266HR roller cam, EDIS/Megajolt ignition, long headers), T5Z w/Steeda TriAx shifter, 9" Trac Loc w/3. Seems to happen more dramatically under hard braking. If the system is having a hesitation or bogging issue, and you IAC steps are between 3-10 at warm idle, then your next step would be to adjust the accel pump function to increase or decrease the fuel added on acceleration. Hello all, I'd had a bog/stumble issue that I spent much time trying to tune out but basically learned how to drive around it: rolling into the throttle in first (350 turbo manually shifting) just to get the car moving, THEN hammering it. I have been driving the car consistently for 3 or 4 days now, maybe 12 hours driving total. Engine misfire – poor air/fuel mixture in the cylinders can cause an incomplete combustion event. It could even cut out completely. It gets worse if try to hold at that speed. I have been driving the car consistently for 3 or 4 days now, maybe 12 hours driving total. From the main menu go to the very bottom and select Write Cal To ECU. A 340-lph high-pressure pump is submerged inside the unit to feed high-pressure fuel to the EFI. This should only be attempted with the engine at normal operating temperature – which for the FiTech is above 160 degrees F. I added a ground wire from FITECH TB to chassis ground, made sure I have a good ground with a meter. It will drop RPM's way too low. 04/26/16, 09:10 AM. All you need to do is answer a few basic questions and the EZ EFI does the rest. FiTech EFI - Basic Setup Instructions. After a minute or 2 its fine and doesn't do it again until its cold. To start with turn the key to the on position and then find Go EFI Tuning on the main menu and press enter. If accelerating hard, there is a 2 second hesitation, whether moving or from a stop so I'm constantly modulating the throttle to eliminate hesitation. Just revving the car up in Neutral has similar results. Also it will run right up to 5500 if I use a slow and steady acceleration. Engine misfire – poor air/fuel mixture in the cylinders can cause an incomplete combustion event. I finally gave up and gave in with this fitech issue I am having. Forum Navigation. Hi there, Finally got my Chevelle out of the garage with the new engine this morning. Record some data runs and import them to a computer. If the system is having a hesitation or bogging issue, and you IAC steps are between 3-10 at warm idle, then your next step would be to adjust the accel pump function to increase or decrease the fuel added on acceleration. Stumble on fast accelerationBy noexpert · 1 2. This should only be attempted with the engine at normal operating temperature – which for the FiTech is above 160 degrees F. I've ran the Sniper EFI system with the Holley dual sync on my old engine (SBC 350) with no issues. Car is a 1976 Fleetwood Brougham with carburetor. This is done by controlling the voltage to the Command Center. Fitech inline fuel kit installed below tank within 2 feet. just a video for Fitech tech Mike, showing smooth idle, until throttle is added. On the other hand, it can also cause your car to have spontaneous accelerations even if you didn't step on the gas. Seems to happen more dramatically under hard braking. has a slight stumble/lag when it pops then accelerates on up. Mar 28, 2013 · Cam is a 239/245. The AFR at that time is about 15:1 16:1, and corrects itself quickly to 13:1. Jul 16, 2008 · Air/Fuel Mixture Tuning Guidelines. I think fuel pressure is ok. Revolutionary anti-cellulite treatment and body contouring for fast and efficient results. I have my IAC steps set exactly where Fitech wants them but they are very erratic because of the cam. I'm not real sure but i think it may be when the secondaries are kicking in. Forum Navigation. They are vacuum. EFI Questions Answered With The Help Of Ken Farrell at FiTech. You should have the fuel pressure regulator replaced and the oil and filter replaced. Forum Navigation. One side of the cable connects to the wire harness of your FiTech system, and the other to the handheld. Just revving the car up in Neutral has similar results. Mar 28, 2013 · Cam is a 239/245. They've enabled going to fuel injection with the least obtrusive modifications from the car's original configuration. Been doing all sorts of driving from start & stop traffic, to WOT, to. This is why a steady throttle foot is necessary for best EFI fuel economy. I finally gave up and gave in with this fitech issue I am having. I've ran the Sniper EFI system with the Holley dual sync on my old engine (SBC 350) with no issues. A 340-lph high-pressure pump is submerged inside the unit to feed high-pressure fuel to the EFI. Joined Sep 18, 2000 · 723 Posts. Oct 16, 2019. 3 Basic Causes of Stumble As with engines before the days of Electronic Fuel Injection (EFI), stumble had two basic causes- incorrect ignition and incorrect fuel/ air mixture for the required operating condition. Your engine may start up but it will have little to no power and it causes it to shut off. Dec 12, 2018 · So I had Fitech electronic TBI installed. These are a basic overview of the most common setup questions. During certain situations, the injectors can be turned off. We added a MSD 6Al. FiTech EFI Tuning Forum. 18 Replies · 11,720 ViewsLast post: 3 years ago · texcuda. The Fitech runs fine on dual plane intakes, however a single plane is "supposed to" be better for overall fuel distribution since all 4 barrels open at the same time. Then, find Go EFI Tuning on the main menu and press Enter. It gets worse if try to hold at that speed. hi guys, been working almost 7 days a week and haven't been around much to bug you, but need some help now. Also have noticed a exhaust pop and a leaner AFR on closed throttle decell, at around 17 to 18. Acceleration issues: A bad TPS may cause all sorts of power issues. Seems like it might be a good match and not have issues with being over carbed. Once on this file select it and it will download to 100 percent. Unfortuantely, when driving on the road, it knocks under load at lower RPM. 89:1, 31 spline axles. Fitech tech team has suggested several things and no change. had a chance to get the mustang out for a little ride and having issue. Search titles only; Posted by Member: Separate names with a comma. Seems to happen more dramatically under hard braking. A lean hesitation vs a fuel rich bog cannot always be deduced by the seat of your pants. The Fuel Command Center 2 mounts under your hood, and your engine’s mechanical fuel pump feeds the FCC2. I have a slight stumble with a slight lean condition on acceleration on a smooth throttle input. Since the O2 sensor plays such a vital role in making your engine and emissions systems function properly, poor fuel economy, poor engine performance, rough idling, a failed emissions test, and even vehicle stalling all could occur if your vehicle’s O2 sensors have. 100% HANDS-FREE TECHNOLOGY CAN BE COMBINED WITH. It now runs good, but after 20 minutes of around town driving it begins again to stumble. just a video for Fitech tech Mike, showing smooth idle, until throttle is added. If I try hard acceleration (not full throttle, engine is still being broke in) it hesitates badly and finally will catch up. Bogging, hesitation, stumbling when warm. May 11, 2017 · It starts fine. 18 Replies · 11,720 ViewsLast post: 3 years ago · texcuda. Forum Navigation. If the system is having a hesitation or bogging issue, and you IAC steps are between 3-10 at warm idle, then your next step would be to adjust the accel pump function to increase or decrease the fuel added on acceleration. The engine still stumbles and backfires through the carb. They’ve enabled going to fuel injection with the least obtrusive modifications from the car’s original. If accelerating hard, there is a 2 second hesitation, whether moving or from a stop so I'm constantly modulating the throttle to eliminate hesitation. To start with, turn the key to the ON position. or so and then once the IAC counts fall to 30 and stop dropping, that is when it starts to over shoot. Acceleration issues: A bad TPS may cause all sorts of power issues. There are more than 33 items, which if faulty, that can cause engine hesitation and stumble problems. They’ve enabled going to fuel injection with the least obtrusive modifications from the car’s original. Ahh good point. I have a slight stumble with a slight lean condition on acceleration on a smooth throttle input. This wetness changes with temperature, engine vacuum, and air flow speeds. 3 hp at 6,800 rpm. 100% HANDS-FREE TECHNOLOGY CAN BE COMBINED WITH. Feb 24, 2021 · FWIW, I can run in 5th gear at 38 mph, 1100 rpm and engine is smooth and will accelerate without hesitation, bogging or stumbles. Occasionally it does stall. 0 -20) and almost dies. What likely needs adjusting is the Fast Accel values (at least at 170 degrees) which is the pump shot when you stab the go pedal. Oct 12, 2020 · Without hesitation and desperate for any progress, we switched it to the other notch and it fit in super snug (this was about a 90° rotation of the cap ONLY, NOT the entire unit). Don't have a timing light handy, so I just advanced the timing about a 1/8-1/4 inch distributor turn. just a video for Fitech tech Mike, showing smooth idle, until throttle is added. Car is a 1976 Fleetwood Brougham with carburetor. Discussion Starter · #1 · Apr 14, 2018. On the other hand, it can also cause your car to have spontaneous accelerations even if you didn't step on the gas. has a slight stumble/lag when it pops then accelerates on up. Also it will run right up to 5500 if I use a slow and steady acceleration. 100% HANDS-FREE TECHNOLOGY CAN BE COMBINED WITH. Been doing all sorts of driving from start & stop traffic, to WOT, to. Issues: after acceleration and on deceleration from cruising or WOT, AFR goes way lean (16. May 11, 2017 · It starts fine. FiTech Fuel Injection has been supplying automotive products, specifically fuel injection products, since 2012. Jul 16, 2008 · Air/Fuel Mixture Tuning Guidelines. 0 -20) and almost dies. Note* this post assumes that you already know how to time a running engine, just not one that never been run before or has had its distributor removed and its timing settings lost. Mar 15, 2018 · A lean mixtute that didn't get more advance would hesitate, so it's really the opposite. Aug 24, 2010 · Couple of weeks ago, out of the blue this problem started. However, there are many do’s, don’ts, and rules of thumb that can be frustrating to learn the hard way. I broke in the cam on the new engine (SBC 400) with the sniper and dual sync, also with really no issues. After many hours of tunning the car starts and runs great, warms up and idle settles. IAC values are low though, around 30. « on: December 18, 2015, 02:57:27 PM ». At high RPM, the injectors and spark can be cut off at the Rev Limit RPM in order to prevent the. During certain situations, the injectors can be turned off. 65 chevelle 283 2 barrel rochester, bone stock. Hello all, I'd had a bog/stumble issue that I spent much time trying to tune out but basically learned how to drive around it: rolling into the throttle in first (350 turbo manually shifting) just to get the car moving, THEN hammering it. Search titles only; Posted by Member: Separate names with a comma. Anyway, getting back to my "fix". From the main menu go to the very bottom and select Write Cal To ECU. Intake manifolds are going to get wet with fuel while running. Two, you have got some fuel control values set too high, such as the accel pump and fast accel pump, to start. 18 Replies · 11,720 ViewsLast post: 3 years ago · texcuda. They are vacuum. Stumble on fast accelerationBy noexpert · 1 2. This unit is designed to be used in vehicles still using stock fuel tanks, but, have converted from using a carburetor to EFI. They’ve enabled going to fuel injection with the least obtrusive modifications from the car’s original. Barely a turn of the key it fires and idles for a second then it wants to idle low. Timing is set to service manual specs; changed carb out 3 times; a new fuel pump with correct amount of pressure, and a new filter. or so and then once the IAC counts fall to 30 and stop dropping, that is when it starts to over shoot. Lastly, RUN A DATA LOG under all conditions so you can see what is really happening. Also it will run right up to 5500 if I use a slow and steady acceleration. Fitech tech team has suggested several things and no change. just a video for Fitech tech Mike, showing smooth idle, until throttle is added. It takes 5-6 revolutions to get it to light off. Super smooth idle. The engine still stumbles and backfires through the carb. I'm not real sure but i think it may be when the secondaries are kicking in. The problem continued to occur. Once on this file select it and it will download to 100 percent. Note* this post assumes that you already know how to time a running engine, just not one that never been run before or has had its distributor removed and its timing settings lost. All you need to do is answer a few basic questions and the EZ EFI does the rest. If I try hard acceleration (not full throttle, engine is still being broke in) it hesitates badly and finally will catch up. Also when the engine is floored with the accelerator pedal, the engine dies unless you let up right away on the gas. Newer Than:. When cruising along and either rolling on the throttle or punching it, have a severe hesitation. Overhaul kits are available but I noticed Summit Racing in the US have "remade" units available at a reasonable price. I have a slight stumble with a slight lean condition on acceleration on a smooth throttle input. Turbo Charged - 10 lbs. I had a 4-hole spacer first which was said to be the worst that can be done with the EFI so i added an open on and that is supposed to even out any fuel distribution issues on the. I added a ground wire from FITECH TB to chassis ground, made sure I have a good ground with a meter. The first step is to ensure the TPS reads 0 with the key on and engine idling. Listening at the exhaust pipe, you can hear a 'phut, phut, phut' noise when the ening is missing. If the system is having a hesitation or bogging issue, and you IAC steps are between 3-10 at warm idle, then your next step would be to adjust the accel pump function to increase or decrease the fuel added on acceleration. Intake manifolds are going to get wet with fuel while running. FOR THE NEW P1 on cover file. Also have noticed a exhaust pop and a leaner AFR on closed throttle decell, at around 17 to 18. It would only do this when speed got up near 50 mph or greater. Barely a turn of the key it fires and idles for a second then it wants to idle low. This wetness changes with temperature, engine vacuum, and air flow speeds. First off, my kickdown cable has always been spot on and very responsive. 18 Replies · 11,720 ViewsLast post: 3 years ago · texcuda. Oct 05, 2016 · If the system is having a hesitation or bogging issue, and you IAC steps are between 3-10 at warm idle, then your next step would be to adjust the accel pump function to increase or decrease the fuel added on acceleration. If you have a momentary lean spike, on light throttle acceleration, check your AE vs TPS/MAP RoC Blanking values (in Fuel Modifiers/Fuel Control): If they're 15 & 7, those are the old values from the V1 ECU firmware. Feb 27, 2017 · The engine made 681. When cruising along and either rolling on the throttle or punching it, have a severe hesitation. By Andy Bolig December 12, 2017. 0 -20) and almost dies. May 11, 2017 · It starts fine. If I try hard acceleration (not full throttle, engine is still being broke in) it hesitates badly and finally will catch up. 18 Replies · 11,720 ViewsLast post: 3 years ago · texcuda. When I get it up to say 50 or 60 mph, the stumble goes away but at the cruise speed. Hi there, Finally got my Chevelle out of the garage with the new engine this morning. I will use a short section of hose with clamps on each end and connect to a 3/8 steel line, with a AN6 on the end to connect to a vent valve. Super smooth idle. It also had a stumble when accelerating when the car was already at speed. This is a little how-to for setting the initial ignition timing on a small block Chevy before its ever been run. If accelerating hard, there is a 2 second hesitation, whether moving or from a stop so I'm constantly modulating the throttle to eliminate hesitation. May 31, 2021 · A stumble or a “hanging throttle” on deceleration can be caused by an improperly set idle air-control (IAC) motor position. New Sniper Dieseling & Backfiring Under Heavy Acceleration Hi just got my Sniper installed on my 351 Cleveland engine, no timing control, 9:5:1 CR and I'm experiencing some problems. EFI Questions Answered With The Help Of Ken Farrell at FiTech. The most common causes for backfiring during acceleration include an incorrect fuel-to-air ratio, a faulty ignition and bad wiring. This is why a steady throttle foot is necessary for best EFI fuel economy. At high RPM, the injectors and spark can be cut off at the Rev Limit RPM in order to prevent the. engine stumbles on acceleration, need help. So I set the timing back, now I have no knock, but the bog is back. I looked at my logs, and I noticed that there is a brief dip to an AFR in the 10's between 2000-3000 RPM on WOT from idle or low RPM. 7 V8 - Stock w/ edelbrock intake. You may have to have the spark plugs removed to get the fuel out of the cylinders or fuel will lock the motor from turning over. These are a basic overview of the most common setup questions. The problem continued to occur. Super smooth idle. The most common causes for backfiring during acceleration include an incorrect fuel-to-air ratio, a faulty ignition and bad wiring. Hi there, Finally got my Chevelle out of the garage with the new engine this morning. First off, my kickdown cable has always been spot on and very responsive. Backfiring during acceleration occurs when ignition takes place in the intake or exhaust instead of the combustion chamber. Occasionally it does stall. But under hard acceleration the motor stalls, just cuts off as soon as the 3000 rpm hits. It is slowing the speed at which the pump is running. I know a lot of guys change them to deal with the problem. Like 500 rpm. May 18, 2007 · The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1967 - 1972 Chevrolet & GMC Pickups Message Board: holley accelerator pump question. It takes 5-6 revolutions to get it to light off. This wetness changes with temperature, engine vacuum, and air flow speeds. With that established, we need to find what FiTech calls IAC steps. when doing this. Seems to happen more dramatically under hard braking. 18 Replies · 11,720 ViewsLast post: 3 years ago · texcuda. If the system is having a hesitation or bogging issue, and you IAC steps are between 3-10 at warm idle, then your next step would be to adjust the accel pump function to increase or decrease the fuel added on acceleration. I had a 4-hole spacer first which was said to be the worst that can be done with the EFI so i added an open on and that is supposed to even out any fuel distribution issues on the. I looked at my logs, and I noticed that there is a brief dip to an AFR in the 10's between 2000-3000 RPM on WOT from idle or low RPM. Also the FiTech will NOT pump in enough gas on a cold start to make it light off immediately when cold either. If you have a momentary lean spike, on light throttle acceleration, check your AE vs TPS/MAP RoC Blanking values (in Fuel Modifiers/Fuel Control): If they're 15 & 7, those are the old values from the V1 ECU firmware. 100% HANDS-FREE TECHNOLOGY CAN BE COMBINED WITH. To all those who use the Fitech 600 system, I need your help. Two mechanics couldn't find the answer. Seems to happen more dramatically under hard braking. Forum Navigation. Mar 06, 2016 · :cool: ZWy_Q-Fimt4. So I set the timing back, now I have no knock, but the bog is back. I can't tell any difference at WOT with the spacer or not. FAST's EZ EFI system is an extremely versatile system for virtually for anyone that is looking to switch from traditional carburetor, or even as a controller for currently fuel injected cars. Issues: after acceleration and on deceleration from cruising or WOT, AFR goes way lean (16. We added a MSD 6Al. After a minute or 2 its fine and doesn't do it again until its cold. Jul 16, 2008 · Air/Fuel Mixture Tuning Guidelines. I wasn't willing to pay thousands for their guesses. Just to mess things up what are your thoughts on something like the small fitech unit. I called FiTech and they suggested I lower my FAST ACCEL setting to -10. Occasionally it does stall. All the screws aligned perfectly within their slots as well. 5 hp at 6,600 rpm and 601. hi guys, been working almost 7 days a week and haven't been around much to bug you, but need some help now. Forum Navigation. Joined Sep 18, 2000 · 723 Posts. At most it would be a little rich. Your engine may start up but it will have little to no power and it causes it to shut off. My only tuning issues at the moment are idle and deceleration. When I get it up to say 50 or 60 mph, the stumble goes away but at the cruise speed. Unstable Engine Idle: Faulty position sensors can cause sporadic idle. I am beginning to think the small valves create such a high velocity that it dries out the manifold for an instant. Car is a 1976 Fleetwood Brougham with carburetor. The vehicle backfires at 40mph and will not go over that speed, acceleration and deceleration are perfect, lots of power but just stops at 40 mph with backfiring. It will sometimes try to die if I don't throw it in neutral and keep the revs up after a hard acceleration followed by a hard brake. They’ve enabled going to fuel injection with the least obtrusive modifications from the car’s original. On a carb, when the throttle is slammed open, nothing happens (outside of the accel pump shot) until air velocity through the carb's throttle bores increases. Any time the exhaust is “opened up” the condition of deceleration pops is MUCH more noticeable and problematic. I finally gave up and gave in with this fitech issue I am having. Also, you don't need to be adjusting the Accel Pump values those should be fine in the base program. 7 V8 - Stock w/ edelbrock intake. I found many suggestions but didn't find many that said their suggestions worked. just a video for Fitech tech Mike, showing smooth idle, until throttle is added. Mar 06, 2016 · :cool: ZWy_Q-Fimt4. I have my IAC steps set exactly where Fitech wants them but they are very erratic because of the cam. This is why a steady throttle foot is necessary for best EFI fuel economy. Then, we swapped it out for the LSXrt top, and power jumped to 703. 89:1, 31 spline axles. They are vacuum. 3 hp at 6,800 rpm. 04/26/16, 09:10 AM. Fitech inline fuel kit installed below tank within 2 feet. 65 chevelle 283 2 barrel rochester, bone stock. If you have a momentary lean spike, on light throttle acceleration, check your AE vs TPS/MAP RoC Blanking values (in Fuel Modifiers/Fuel Control): If they're 15 & 7, those are the old values from the V1 ECU firmware. If you can access it with your system, another good thing to adjust is the PWM Threshold RPM. Note* this post assumes that you already know how to time a running engine, just not one that never been run before or has had its distributor removed and its timing settings lost. Issues: after acceleration and on deceleration from cruising or WOT, AFR goes way lean (16. Fitech tech team has suggested several things and no change. Also have noticed a exhaust pop and a leaner AFR on closed throttle decell, at around 17 to 18. If the system is having hesitation or bogging issue, and your IAC steps are between 3-10 at warm idle, then your next step would be to adjust the accel pump function to increase or decrease the fuel added on acceleration. To all those who use the Fitech 600 system, I need your help. I have a slight stumble with a slight lean condition on acceleration on a smooth throttle input. It will sometimes try to die if I don't throw it in neutral and keep the revs up after a hard acceleration followed by a hard brake. FiTech System This is not hard. Any time the exhaust is “opened up” the condition of deceleration pops is MUCH more noticeable and problematic. Bogging, hesitation, stumbling when warm. FOR THE NEW P1 on cover file. Also, you don't need to be adjusting the Accel Pump values those should be fine in the base program. Fitech tech team has suggested several things and no change. RPM heads, RPM intake, FiTech EFI, Comp XE266HR roller cam, EDIS/Megajolt ignition, long headers), T5Z w/Steeda TriAx shifter, 9" Trac Loc w/3. FiTech System This is not hard. I added a ground wire from FITECH TB to chassis ground, made sure I have a good ground with a meter. It also had a stumble when accelerating when the car was already at speed. Backfires occur in engines with severe malfunctions, such as those with diverter valve. On a carb, when the throttle is slammed open, nothing happens (outside of the accel pump shot) until air velocity through the carb's throttle bores increases. To start with turn the key to the on position and then find Go EFI Tuning on the main menu and press enter. The car starts, idles and runs ok under gentle acceleration. Super smooth idle. If I try hard acceleration (not full throttle, engine is still being broke in) it hesitates badly and finally will catch up. The car would stumble as soon as the throttle was cracked open from idle. Backfiring during acceleration occurs when ignition takes place in the intake or exhaust instead of the combustion chamber. If accelerating hard, there is a 2 second hesitation, whether moving or from a stop so I'm constantly modulating the throttle to eliminate hesitation. 7 V8 - Stock w/ edelbrock intake. 65 chevelle 283 2 barrel rochester, bone stock. Seems to happen more dramatically under hard braking. Jump to Latest Follow 1 - 7 of 7 Posts. engine stumbles on acceleration, need help. The Deceleration Pop Problem Decel Pop is many times a nasty issue to deal with. Dirty, clogged, blocked, leaking or generally faulty fuel injectors have the following symptoms: Engine stutter, hesitation, stumbling – without the proper air/fuel mixture, the combustion inside the cylinders is impeded. has a slight stumble/lag when it pops then accelerates on up. 5 hp at 6,600 rpm and 601. Anyway, getting back to my "fix". If the system is having hesitation or bogging issue and your IAC steps are between 3-10 at warm idle, then your next step would be to adjust the accel pump function to increase or decrease the fuel added on acceleration. You may have to have the spark plugs removed to get the fuel out of the cylinders or fuel will lock the motor from turning over. To start with turn the key to the on position and then find Go EFI Tuning on the main menu and press enter. I called the carb place that rebuilt it and they said it must be an electrical or iginition problem as a backfiring problem is 99% electircal. FAST's EZ EFI system is an extremely versatile system for virtually for anyone that is looking to switch from traditional carburetor, or even as a controller for currently fuel injected cars. FiTech EFI - Basic Setup Instructions. Timing is set to service manual specs; changed carb out 3 times; a new fuel pump with correct amount of pressure, and a new filter. Buttons/Navigating. These are a basic overview of the most common setup questions. just a video for Fitech tech Mike, showing smooth idle, until throttle is added. Starts up fine and idles smooth cold or warm. I will be using a Tanks Inc EFI tank that has AN fittings for the supply and return lines, and a 5/16" barbed fitting for the vent. Jul 29, 2021 · If you step on the gas pedal and notice a lack of acceleration, then it could be due to the fuel pressure sensor. They've enabled going to fuel injection with the least obtrusive modifications from the car's original configuration. Also when the engine is floored with the accelerator pedal, the engine dies unless you let up right away on the gas. This will cause a noticeable loss of power from your vehicle as you’re driving. The car starts, idles and runs ok under gentle acceleration. just a video for Fitech tech Mike, showing smooth idle, until throttle is added. « on: December 18, 2015, 02:57:27 PM ». FAST is the leading developer of electronic fuel injection systems, EFI components, intake manifolds, tuning tools for high performance and street applications. Engine recently rebuilt. Main jets don't usually have much of an effect on off-idle and acceleration stumbles. It will drop RPM's way too low. FITech hasn't been knowledgeable when my mechanic tried to deal with the hesitation and frankly, it sounds like they just don't know. It now runs good, but after 20 minutes of around town driving it begins again to stumble. The engine will nearly stall for 2 to 4 seconds, and then take off. FiTech EFI Tuning Forum. We’ll take the example of the FiTech throttle body as our example since we’ve seen this quite often in these systems. They've enabled going to fuel injection with the least obtrusive modifications from the car's original configuration. Barely a turn of the key it fires and idles for a second then it wants to idle low. If you can access it with your system, another good thing to adjust is the PWM Threshold RPM. I called the carb place that rebuilt it and they said it must be an electrical or iginition problem as a backfiring problem is 99% electircal. Any time the exhaust is “opened up” the condition of deceleration pops is MUCH more noticeable and problematic. bhawk · Registered. But when I accelerate leaving my driveway the engine stumbles and very rarely even coughs. Super smooth idle. I broke in the cam on the new engine (SBC 400) with the sniper and dual sync, also with really no issues. No more laptop or expensive tuning sessions are required - everything you need is right there inside, waiting to learn. Listening at the exhaust pipe, you can hear a 'phut, phut, phut' noise when the ening is missing. Like 500 rpm. Unstable Engine Idle: Faulty position sensors can cause sporadic idle. 18 Replies · 11,720 ViewsLast post: 3 years ago · texcuda. Turbo Charged - 10 lbs. I finally gave up and gave in with this fitech issue I am having. Been doing all sorts of driving from start & stop traffic, to WOT, to. Forum Navigation. If the system is having a hesitation or bogging issue, and you IAC steps are between 3-10 at warm idle, then your next step would be to adjust the accel pump function to increase or decrease the fuel added on acceleration. Search titles only; Posted by Member: Separate names with a comma. Anyway, getting back to my "fix". This will cause a noticeable loss of power from your vehicle as you’re driving. It could even cut out completely. I installed a pressure gauge at the inlet, behind the filters and fuel pressure is at 55 psi, increases to 60 psi during fast acceleration. New Sniper Dieseling & Backfiring Under Heavy Acceleration Hi just got my Sniper installed on my 351 Cleveland engine, no timing control, 9:5:1 CR and I'm experiencing some problems. At most it would be a little rich. Turbo Charged - 10 lbs. First off, my kickdown cable has always been spot on and very responsive. I called the carb place that rebuilt it and they said it must be an electrical or iginition problem as a backfiring problem is 99% electircal. FITech hasn't been knowledgeable when my mechanic tried to deal with the hesitation and frankly, it sounds like they just don't know. 3 Basic Causes of Stumble As with engines before the days of Electronic Fuel Injection (EFI), stumble had two basic causes- incorrect ignition and incorrect fuel/ air mixture for the required operating condition. Anyway, getting back to my "fix". I found many suggestions but didn't find many that said their suggestions worked. Replaced the temperature sensor once I realized mine was bad. I broke in the cam on the new engine (SBC 400) with the sniper and dual sync, also with really no issues. Acceleration issues: A bad TPS may cause all sorts of power issues. Any time the exhaust is “opened up” the condition of deceleration pops is MUCH more noticeable and problematic. I'm not real sure but i think it may be when the secondaries are kicking in. 18 Replies · 11,720 ViewsLast post: 3 years ago · texcuda. This wetness also m. Discussion Starter · #1 · May 18, 2008. Stumble on fast accelerationBy noexpert · 1 2. Been doing all sorts of driving from start & stop traffic, to WOT, to. If accelerating hard, there is a 2 second hesitation, whether moving or from a stop so I'm constantly modulating the throttle to eliminate hesitation. I finally gave up and gave in with this fitech issue I am having. 0 -20) and almost dies. The most common causes for backfiring during acceleration include an incorrect fuel-to-air ratio, a faulty ignition and bad wiring. The car starts, idles and runs ok under gentle acceleration. FiTech Fuel Injection has been supplying automotive products, specifically fuel injection products, since 2012. 5 hp at 6,600 rpm and 601. Turbo Charged - 10 lbs. just a video for Fitech tech Mike, showing smooth idle, until throttle is added. FiTech EFI - Basic Setup Instructions. The engineers at FiTech have made an art of building EFI systems that are designed to upgrade carbureted daily-drivers and race vehicles. Overhaul kits are available but I noticed Summit Racing in the US have "remade" units available at a reasonable price. The problem continued to occur. From the main menu go to the very bottom and select Write Cal To ECU. FiTech EFI Tuning Forum. If the system is having a hesitation or bogging issue, and you IAC steps are between 3-10 at warm idle, then your next step would be to adjust the accel pump function to increase or decrease the fuel added on acceleration. Stumble on fast accelerationBy noexpert · 1 2. Then, find Go EFI Tuning on the main menu and press Enter. 04/26/16, 09:10 AM. FiTech EFI Tuning Forum. There are more than 33 items, which if faulty, that can cause engine hesitation and stumble problems. All the screws aligned perfectly within their slots as well. Works fine and has a soft landing for the first 5 min. During certain situations, the injectors can be turned off. If I try hard acceleration (not full throttle, engine is still being broke in) it hesitates badly and finally will catch up. Checked fuel pressures on the FC, they do waver when the car starts to stumble and sputter, but it does recover after filter cleaning I still have the Carter Carb electric fuel pump out back by the tank, will clean the screen in that tonight. I added a ground wire from FITECH TB to chassis ground, made sure I have a good ground with a meter. When cruising along and either rolling on the throttle or punching it, have a severe hesitation. To start with turn the key to the on position and then find Go EFI Tuning on the main menu and press enter. Our folks have several options from basic to completely trick. Contact us. After many hours of tunning the car starts and runs great, warms up and idle settles. To all those who use the Fitech 600 system, I need your help. It’s just a cable. Turbo Charged - 10 lbs. The vehicle backfires at 40mph and will not go over that speed, acceleration and deceleration are perfect, lots of power but just stops at 40 mph with backfiring. 0 -20) and almost dies. If accelerating hard, there is a 2 second hesitation, whether moving or from a stop so I'm constantly modulating the throttle to eliminate hesitation. Dropping it down to about 1500 will make sure the fuel pump keeps the pressure up under hard acceleration. Also, you don't need to be adjusting the Accel Pump values those should be fine in the base program. Jan 28, 2010 · Download this technical bulletin as a PDF Advanced Tips for EFI Tuning with Fuel Pressure Changing the fuel pressure on an EFI System is an effective method of affecting engine performance and making more power. Hi there, Finally got my Chevelle out of the garage with the new engine this morning. Replaced the temperature sensor once I realized mine was bad. 7 V8 - Stock w/ edelbrock intake. During certain situations, the injectors can be turned off. I called the carb place that rebuilt it and they said it must be an electrical or iginition problem as a backfiring problem is 99% electircal. engine stumbles on acceleration, need help. Sometimes the smallest things can cause the largest problems, and in the case of a failing O2 sensor, this certainly holds true. Also have noticed a exhaust pop and a leaner AFR on closed throttle decell, at around 17 to 18. Jeep fired RIGHT UP. This can also be. Engine recently rebuilt. By Andy Bolig December 12, 2017. engine stumbles on acceleration, need help. This is a little how-to for setting the initial ignition timing on a small block Chevy before its ever been run. I finally gave up and gave in with this fitech issue I am having. I'm not real sure but i think it may be when the secondaries are kicking in. Seems to happen more dramatically under hard braking. Search titles only; Posted by Member: Separate names with a comma. Listening at the exhaust pipe, you can hear a 'phut, phut, phut' noise when the ening is missing. Timing is set to service manual specs; changed carb out 3 times; a new fuel pump with correct amount of pressure, and a new filter. 100% HANDS-FREE TECHNOLOGY CAN BE COMBINED WITH. FITech hasn't been knowledgeable when my mechanic tried to deal with the hesitation and frankly, it sounds like they just don't know. I spent many hours on internet looking for answers to "rough idle, acceleration hesitation" problem. By Andy Bolig December 12, 2017. This is done by controlling the voltage to the Command Center. To start with, turn the key to the on position and then find Go EFI Tuning on the main menu and press enter. Holley 600 dbl pumper manual secondaries, EDL RPM airgap intake, FMS E-cam 302 crate motor. Newer Than:. If the system is having a hesitation or bogging issue, and you IAC steps are between 3-10 at warm idle, then your next step would be to adjust the accel pump function to increase or decrease the fuel added on acceleration. Checked fuel pressures on the FC, they do waver when the car starts to stumble and sputter, but it does recover after filter cleaning I still have the Carter Carb electric fuel pump out back by the tank, will clean the screen in that tonight. 18 Replies · 11,720 ViewsLast post: 3 years ago · texcuda. Discussion Starter · #1 · May 18, 2008. May 31, 2021 · A stumble or a “hanging throttle” on deceleration can be caused by an improperly set idle air-control (IAC) motor position. Intake manifolds are going to get wet with fuel while running. Jeep fired RIGHT UP. It will sometimes try to die if I don't throw it in neutral and keep the revs up after a hard acceleration followed by a hard brake. We added a MSD 6Al. Intake manifolds are going to get wet with fuel while running. Feb 27, 2017 · The engine made 681. 18 Replies · 11,720 ViewsLast post: 3 years ago · texcuda. My problem is a severe stumble on fast acceleration that does not resolve no matter how much adjustment I make to Accel Pump, or Fast Accel inputs. Any ideas out there? Also the FiTech will NOT pump in enough gas on a cold start to make it light off immediately when cold either. FiTech Fuel Injection has been supplying automotive products, specifically fuel injection products, since 2012. If the system is having a hesitation or bogging issue, and you IAC steps are between 3-10 at warm idle, then your next step would be to adjust the accel pump function to increase or decrease the fuel added on acceleration. FITech hasn't been knowledgeable when my mechanic tried to deal with the hesitation and frankly, it sounds like they just don't know. 04/26/16, 09:10 AM. I have a slight stumble with a slight lean condition on acceleration on a smooth throttle input. Lastly, RUN A DATA LOG under all conditions so you can see what is really happening. This is a little how-to for setting the initial ignition timing on a small block Chevy before its ever been run. At high RPM, the injectors and spark can be cut off at the Rev Limit RPM in order to prevent the. Issues: after acceleration and on deceleration from cruising or WOT, AFR goes way lean (16. Acceleration issues: A bad TPS may cause all sorts of power issues. It has a Carter Thermoquad unit fitted with I guess is original. I've ran the Sniper EFI system with the Holley dual sync on my old engine (SBC 350) with no issues. New Sniper Dieseling & Backfiring Under Heavy Acceleration Hi just got my Sniper installed on my 351 Cleveland engine, no timing control, 9:5:1 CR and I'm experiencing some problems. I think I have read somewhere (possibly another FiTech thread here) that the FiTech system is able to limit the intake of fuel from the mechanical pump, similar to a fuel regulator, to the Command Center. After many hours of tunning the car starts and runs great, warms up and idle settles. I installed a pressure gauge at the inlet, behind the filters and fuel pressure is at 55 psi, increases to 60 psi during fast acceleration. 3 hp at 6,800 rpm. when doing this. May 01, 2017 · 1. Intake manifolds are going to get wet with fuel while running. The car has a very mild 351C 2V with and Edlebrock Performer, and a 700 Holley double pumper carb. The car would stumble as soon as the throttle was cracked open from idle. Joined Sep 18, 2000 · 723 Posts. Been doing all sorts of driving from start & stop traffic, to WOT, to. This unit is designed to be used in vehicles still using stock fuel tanks, but, have converted from using a carburetor to EFI. To all those who use the Fitech 600 system, I need your help. I have a 99 nissan sentra (2. Backfiring during acceleration occurs when ignition takes place in the intake or exhaust instead of the combustion chamber. I can't tell any difference at WOT with the spacer or not. I looked at my logs, and I noticed that there is a brief dip to an AFR in the 10's between 2000-3000 RPM on WOT from idle or low RPM. Sometimes the smallest things can cause the largest problems, and in the case of a failing O2 sensor, this certainly holds true. To start with, turn the key to the ON position. Ahh good point. I know a lot of guys change them to deal with the problem. I broke in the cam on the new engine (SBC 400) with the sniper and dual sync, also with really no issues. If the system is having a hesitation or bogging issue, and you IAC steps are between 3-10 at warm idle, then your next step would be to adjust the accel pump function to increase or decrease the fuel added on acceleration. Seems like it might be a good match and not have issues with being over carbed. Intake manifolds are going to get wet with fuel while running. Make sure the cable doesn’t get pinched and cut anywhere. It will do it for as long as I hold that engine speed. Also, you don't need to be adjusting the Accel Pump values those should be fine in the base program. Don't have a timing light handy, so I just advanced the timing about a 1/8-1/4 inch distributor turn. Occasionally it does stall. IAC values are low though, around 30. Unstable Engine Idle: Faulty position sensors can cause sporadic idle. Brand new carb, new Summit e-core coil, new GM module. With that established, we need to find what FiTech calls IAC steps. To start with, turn the key to the on position and then find Go EFI Tuning on the main menu and press enter. Any time the exhaust is “opened up” the condition of deceleration pops is MUCH more noticeable and problematic. Anyway, getting back to my "fix". Stumble on fast accelerationBy noexpert · 1 2. No more laptop or expensive tuning sessions are required - everything you need is right there inside, waiting to learn. This is done by controlling the voltage to the Command Center. when doing this. Also when the engine is floored with the accelerator pedal, the engine dies unless you let up right away on the gas. Hi there, Finally got my Chevelle out of the garage with the new engine this morning. They are vacuum. After a minute or 2 its fine and doesn't do it again until its cold. just a video for Fitech tech Mike, showing smooth idle, until throttle is added. Stumble on fast accelerationBy noexpert · 1 2. May 31, 2021 · A stumble or a “hanging throttle” on deceleration can be caused by an improperly set idle air-control (IAC) motor position. This should only be attempted with the engine at normal operating temperature – which for the FiTech is above 160 degrees F. has a slight stumble/lag when it pops then accelerates on up. While sitting in neutral I can go WOT and it starts to stumble just past 3300 RPM. They've enabled going to fuel injection with the least obtrusive modifications from the car's original configuration. To start with turn the key to the on position and then find Go EFI Tuning on the main menu and press enter. One side of the cable connects to the wire harness of your FiTech system, and the other to the handheld. Bogging, hesitation, stumbling when warm. To start with, turn the key to the ON position. The problem continued to occur. Mar 28, 2013 · Cam is a 239/245. I looked at my logs, and I noticed that there is a brief dip to an AFR in the 10's between 2000-3000 RPM on WOT from idle or low RPM. bhawk · Registered. Issues: after acceleration and on deceleration from cruising or WOT, AFR goes way lean (16. The vehicle backfires at 40mph and will not go over that speed, acceleration and deceleration are perfect, lots of power but just stops at 40 mph with backfiring. Your engine may start up but it will have little to no power and it causes it to shut off.