Slight Hesitation at partial throttle - Ideas?
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Location: Augusta Township, MI
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Car: 1985 IROC-Z
Engine: 383
Transmission: 700R4
Axle/Gears: 3.73
Slight Hesitation at partial throttle - Ideas?
Now that the body work is done on my car, I can finally start to put some miles on it & have some fun. I was driving it today when I noticed an issue, I'm hoping someone can point me in the right direction.
First, the car: 1985 Camaro with a 383, HSR, '730 ECM.
When you gently press down on the accelerator, there is a hesitation & stutter. It's most noticeable when taking off from a dead stop, but you can also feel it if you are already moving at just about any speed. If you really stomp on the gas or press down on the accelerator quick/hard, the car goes without an issue. The problem exists both when the car is cold and when hot, it doesn't seem to change any based on the engine temp.
At different times when driving, shortly after this happens I think I smell something - not gas, but the smell of the vehicle changes, like it's burning too rich or too lean or something.
I had all kinds of problems when I first installed this engine (the builder had the timing gears a tooth off), I wonder if I fouled out the spark plugs or something when I was trying to get it going?
I just used TTS Datamaster to datalog on a 45-minute drive, would this show up in that file? If so, where would I look?
Hoping someone can point me in the right direction. Thank you.
First, the car: 1985 Camaro with a 383, HSR, '730 ECM.
When you gently press down on the accelerator, there is a hesitation & stutter. It's most noticeable when taking off from a dead stop, but you can also feel it if you are already moving at just about any speed. If you really stomp on the gas or press down on the accelerator quick/hard, the car goes without an issue. The problem exists both when the car is cold and when hot, it doesn't seem to change any based on the engine temp.
At different times when driving, shortly after this happens I think I smell something - not gas, but the smell of the vehicle changes, like it's burning too rich or too lean or something.
I had all kinds of problems when I first installed this engine (the builder had the timing gears a tooth off), I wonder if I fouled out the spark plugs or something when I was trying to get it going?
I just used TTS Datamaster to datalog on a 45-minute drive, would this show up in that file? If so, where would I look?
Hoping someone can point me in the right direction. Thank you.
#2
Supreme Member
Re: Slight Hesitation at partial throttle - Ideas?
Is there a hissing sound behind your heater control unit?
#4
Supreme Member
Re: Slight Hesitation at partial throttle - Ideas?
Checked elsewhere for vacuum leaks?
If not a vacuum issue causing the ECM to fight the leaks while it compensates against excess intake air, then some sort of issue likely with the mechanical elements of the fuel delivery system. Have you troubleshooted the fuel pressure regulator?
If not a vacuum issue causing the ECM to fight the leaks while it compensates against excess intake air, then some sort of issue likely with the mechanical elements of the fuel delivery system. Have you troubleshooted the fuel pressure regulator?
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theshackle
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09-17-2020 08:26 AM