Stutter or stumble under slow acceleration?
Stutter or stumble under slow acceleration? I am not sure if this is a part issue or tuning issue, so I figured I would post it here. Under light acceleration (like one would accelerate if leaving a stop light with a cop behind you) my car gets a nasty stumble and feels like it loses a little power. At WOT it is an animal and will break the tires free no problem. Also I scanned the computer there are no codes. Any input? Is this a tuning issue? TPS? The only mods are Lid, Headers, Exhaust, ORY, and Motor Mounts. The car is still on a stock tune and runs super pig rich.....Could it be loading up with fuel? I hope its a tuning issue. Any input would be appreciated.
does it happen every time? id start with fuel pressure first. my car did that when it had a bad fuel pump. if its fine then go to spark plugs and see what happens from there.. good luck
EDIT: you might wanna check your fuel filter too!
TECH Apprentice
Joined: May 2004
Posts: 318
Likes: 14
From: Chicago, IL
I'd like to hear any advice on this too, I was going to post this but never got to it. I have the same problem. For me, though, I don't have to be that light on the throttle. Even if I give it a little kick, it does it to me. However, just like you, OP, on WOT, I don't have this problem.
I'd like to hear any advice on this too, I was going to post this but never got to it. I have the same problem. For me, though, I don't have to be that light on the throttle. Even if I give it a little kick, it does it to me. However, just like you, OP, on WOT, I don't have this problem.
I had a vacuum leak that caused problems at light throttle. Check all your PCV/vacuum hoses for that.
I also had a problem that was open/closed loop related. At full throttle the fueling is taken from a table, so it ran OK. In my case I think 7 out of 8 cylinders were running OK.
At part-throttle/cruise (closed loop) it ran badly. Long story short, for me it was a bad injector. I think what happened was the bad injector made 1 bank of the engine look like it's running lean. To compensate the computer richens the mix on the entire bank, and then you have 4 cylinders with a bad mixture.
I think an exhaust manifold/header leak can give a similar case. I replaced the gaskets there before the injectors but it was OK.
If you have access to a logging tool like efilive you can see this case. For me in cruise mode 1 bank had 2x as much injector duty cycle as the other bank when it ran like crap.
I also had a problem that was open/closed loop related. At full throttle the fueling is taken from a table, so it ran OK. In my case I think 7 out of 8 cylinders were running OK.
At part-throttle/cruise (closed loop) it ran badly. Long story short, for me it was a bad injector. I think what happened was the bad injector made 1 bank of the engine look like it's running lean. To compensate the computer richens the mix on the entire bank, and then you have 4 cylinders with a bad mixture.
I think an exhaust manifold/header leak can give a similar case. I replaced the gaskets there before the injectors but it was OK.
If you have access to a logging tool like efilive you can see this case. For me in cruise mode 1 bank had 2x as much injector duty cycle as the other bank when it ran like crap.
Trending Topics
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
