Guys I need help finding a problem. I have a crazy miss that comes and goes for no reason and we cant find it. We have checked the fuel pressure when the miss happens and everything is fine. We have hooked up the computer and it tells us it is the module. I just changed the module yesterday for the third time and I still have the miss. This thing is driving me INSANE, I lost to a Mustang at the track because of this and I wanted to put the car in the wall I was so mad. It only happens when you launch, and what is even worse is on the way home from the track I launch on the street and NOTHING it was gone. I still changed the module out yesterday and checked everything, well last night I staged and suprise it was back! It is like my car has stage fright! So I got it on video for you guys to see first hand!



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At the start of the night it only missed a little and I was able to run 8.6 1/8 but after 4 passes this is what I was dealing with



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What mods are done? I feel like I have experienced that similar problem from my car from a roll and then punch the throttle... (I believe its a rich fuel mixture)

Since I NEVER get any codes Im under the assumption that its the tune that is on the car. Sending my chip out asap to get it re-flashed and Ill see if it cures the problem. My issue IS NOT as consistant as yours (only happens from time to time) But I will see how she runs when I get it back!

 

If you check out my profile it will tell you everything that has been done to the car.

 

Chip from PCM for less? Mine too... I got mine done when I only had a cat back and an intake. Im curious to see if its the tune... Like I said with all the bolton mods it sounds like when you hit it, its dumping fuel... to compensate for the boltons (most are relative to air flow) and its causing a miss. Thats my assumption. I cant say thats the full problem but thats what I am experiencing!

 

I have tried two chips the PCM and a custom chip.

 

Bump

 

I saw you had checked fuel pressure---however if the fuel pres. gauge hose is long enough-- try taping the gauge to the windshield-- drive it and see what you have when the problem occurs.

 

Thats what we did and my fuel pressure did not change or jump around.

 

Did you have enough fuel in the tank during the launches when you had the miss? My car used to cough if I ran under a half tank at the track.

 

I had over half a tank of fuel, but I had a full tank last night and it did it.

 

How many miles on the opti?

 

This is a ZZ4 crate engine with factory HEI

 

Okay well then you got me beat...

 

We just went through everything and it is still doing it. Now we are going to take the ECM off my friends F body car and try it on my car.

 

Sure sounds like an ignition miss to me. Cap rotor plugs wires sort of thing. Unless it is just the recording it sure sounded like it had a skip for the entire run to be honest. It is pretty hard to make an engine skip from a load dump like launching the car with too much fuel. It might get lazy and nose over but seldom miss fire.

 

It is a new cap, new rotor, new plugs, new module, and new wires.

Last night we changed the TPS ( throttle positioning sensor ) and the problem went away. then I put the old one back on and the problem was still gone.

 

Does anyone have any suggestion as to what could be causing this?? Could it be in the wiring? If so what is the most common place to find these type of issues?

 

I too am having a problem with a random miss. Seems like I have replaced everything on the car..

 

I only have a miss when I do a hard launch and it is not all the time.

 

I would also think ignition issue also.....if the cap, rotor, electrical connections, ICM, plugs and spark wires are good and the HEI coil is still getting "hot" as described in the thread below change the coil out now.....http://forums.corvetteforum.com/c4-t...-question.html