Recently overhauld engine.
On the second lap of a long autocross during a hard right hand turn, the engine will go to idle. If you try and give it any gas, it sounds like it is going to die. Take your foot off of the gas for a few seconds then it will take off and go again.

I put a fuel pressure gage on it and when it goes to idle it reads 42psi.

New Opti and new coil.

I am stummped and do not even know where to start to look.

Any good ideas???????


97 Camaro Z28
6 speed

After talking to my son somemore, it happens after he comes out of the turn either right or left.

 

i assume you had the vacuum line connected then.... unless i am mistaken, you should see something like 36psi at idle, with the vacuum source connected. 42 is somewhere in the neighborhood of what you would get without vacuum connected. were you testing this on the track? it would seem you were by your post.

did you have enough fuel in the tank? maybe it all sloshed to one side?

 

Yes I had the fuel gage taped to the windshield while I made the run. The tank was over half full. I just don't have a clue what it could be.

 

i would be checking out the fpr. make sure vaccum is plugged and not leaking. check for other vacuum leaks too.

 

What is the fpr?????

 

FPR is fuel pressure regulator. Don't think you have a fuel issue though. You said it goes back to idle. I assume even when your foot is in it? Correct? If you had a fuel delivery problem it would pop and fart and you would have seen a pressure change when it happened and RPMS would be all over the place.

Since you said it goes back to idle I would look for the throttle changing position either from a problem with the cable or a motor mount problem. Put the E brake on in the driveway with the engine running and slowly let the clutch out with the hood up and see what's happening with the engine.

Don't know much about your set up but you could use a scanner real time to see what the sensors readings are doing. If you have to duplicate the issue and it's too hard to view the scanner, use its record mode.

 

After it looses power and goes to idle, you can not give it any gas. It does spit etc. and almost die but after a few seconds, you can give it gas and go again. It is odd it does not do it on the firest few laps, just after you have driven hard a couple of times. Since I had the gage mounted when it happened and it did not go down, could it some how be that the PCM is not firing the injectors like it is some kind of limp home mode???? This has never happened on the street, just at the track.

 

Here's a stupid question. Is your battery hold down broke like just about everyone elses here? Is the battery jumping around? I've seen some actually hit ground momentarily and nearly kill the engine on accel. Then it comes back to life like nothing was ever wrong

 

New battery hold. The autocross guys are real picky on the battery being secure before they let you on the track.

It just sounds like a fuel problem to me. I knwo the pressure is up but I was wondering if something had tripped the PCM to keep it from firing the injectors for a while like low oil pressure or something. The oil pressure gage inside did not show low but is there another sensor that the PCM uses?????