A friend of mine who moved to Florida recently (he's got a 96 Z) has this weird problem and I sent him a different PCM to see if it will help, but it seems like it runs just the same with the new PCM.

Anyway, he has some hesitation/loss of power between 4800 and 5300ish RPM 3/4 throttle to WOT. At part throttle, he can go through entire RPM range without a problem. After the lag, the car pulls strong up to 6K WOT.

He also says his PCM is throwing a #5 missfire code at idle, but he's pretty sure the engine doesn't misfire.

He replaced the plugs, wires, opti, injectors and now he has a different PCM from me and still has the same problem. Don't know if this will help, but his mods are 3.73s, bbk shortys, flowmaster exhaust, 52mm TB, GMAF, K&N CAI, 160 stat, 1.6 rockers, accel 26# injectors, Crane digital ignition, and his car is a 6 speed.

I'm thinking it could be the optispark even though he recently changed it. (he said he had the same problems before the new plugs/wires/etc) Maybe the ignition control module or ignition coil?

Any other ideas?
Thanks.

 

A couple of things I would check first is the TPS for linear operation (using a scan tool) and bypass the Crane ignition just for fun.

 

Thanks Rob!

He bypassed the Crane box and he said it only made things worse. Also replaced the TPS and that didn't help any....
Any other ideas?

 

I would try swapping another coil in. Everyone needs a spare, right? It could be breaking down under a load. ICM and opti are always suspects.

 

if he did the ignition box and it only got worse that would go back to looking like a coil or module to me. If the Crane box was unhooked and the coil wasnt getting enuff or the module wasnt either than that could be the issue. Some of those modules dont like heat like mine. I moved mine to the fender and extended all the wires out

 

I just did the ICM cooling mod and it fixed my missing, hesitation problem. It's damn near free. He should try that.

 

I had to go one step further with that cooling mod and I placed mine on the fender by extending the wires about 2 feet. It stopped it all! Not a problem since