I have a 97 z28 .new optispark ,iridium plugs ,racing wires,headers high flow cats,performance cat-back exhaust etc,etc.I just had engine rebuilt 3500 miles ago.Sometimes when i go for a spin i notice i have less power and exhaust is alot quieter.My car will usually be doing 80-85 on the freeway on rampWhen i get on it it seats you back and your seatandit is loud *** hell.When i have no power i am only doing 60-65 flooring it no power and no pull,i can't even burn my tires i power brake but the rpms just keep rising but wont spin tires.The only solution is to pull over and shut the engine off for a minute and restart car and it will be back to normal .I don't know how long this has been happening because i have only been having fun with it and driving it hard for the last 1000 miles.It doesnt always do this sometimes i can let the car warm ip for 5 minutes and it will smoke the tires immediatly, thensometimes i drive it around for an hour plenty of time to warm upand it still has no power.Theonly solution is to restart the car.Any help would be apreciated.Thankyou.

 

it might b the plugs u have,,, I bought the same thing then had some work down at a shop very well trusted for work on LT1 and LS1s and they replaced my plugs with ngks and when i found out i was a lil pissed off cause those iridium plugs aren't cheap 14 bucks a plug and the shop owner told me he would not put those plugs back in, he told me i would loss power and that those type of plugs do not well in LT motor since they r a hot plug and that I needed a cold plug,, but then again i could b wrong, i never had any probs with the plug nut i only ran them 4 about 2000 miles so with headers u should have no prob switching them out and seeing if that helps the shop owner told me that the ngks were the best for my motor and so i would say try ngks the cheap but if they fix the prob then it will b an easy fix,, anyways just my thoughts good luck..

 

[&:] your rising rpms with no turning of the tires is intriguing. so what kind of rpms do you see without turning the tires?? or without an increase in speed kurt

 

anywere from 2500 rpm to 4500 rpm.no power ,no wheels spinning, no throw you back in your seat feeling.

 

your cats might be plugged up

 

plugged cats will produce poor power at all rpms, and all the time not occasionaly. is there any acceleration with this increase in rpm or does the engine just spin faster and faster??

 

I can't remember but is that car drive by wire? When you have the loss of power can you put it in neutral and rev it?

 

Ithas new magnaflow cats and it does accelerate but not like a camaro more like civic and like i said if i shut the engine off for a minute it fixes itself.

 

[] is there any conditions you can associate with the car when this happens?? only cold, up hill around a corner, cars been on for 15 minutes or is it completely random?? could be when passing thru ufo zone

 

what brand of new opti spark??