Heres the deal. When starting the car cold it will run fine until it gets warmed up then it just bogs out cuts out sputters has absolutely no power has to downshift to keep picking up speed and the when you stop and put it in neutral or park and just stomp the pedal to the floor it will not build up above 3000 rpms and its cutting and sputtering badly. Basicaly it sound just like a rev limtiter on an atv. Now its getting to the point i definently can't drive it. For some reason i can't read any codes from the computer (never could) must be a bad wire somewhere. Any help would be appreciated. I am leaning towards opti or 02 sensors. Thanks, Sam

 

May be a clogged cat. What happens when you slam on it when it's cold? May also be a computer problem when it goes into closed loop also the 93' PCM is a pretty simple chip computer. Have you scanned it for codes?

 

Here is some more info to make it evan more confusing awhile back i had to have a new ecm put in and found out i have a motor and all the proper wiring out of a 95 z28 so i had the computer replaced with a 95 model and everything worked fine. I know its been changed because i have a MAF 4 wire o2 sensors and the computer. I cannot read codes i guess because of a bad wire going to plug or something. i don't think it the Cat because it does not get overly hot or turn orange or smell but i don't know much about a plugged cat. When i slam on the gas when its cold it just revs to the redline like nothing is wrong but when its warmed up it will not accelerate past 3000 rpm thats why i am thinking opti

Thanks

 

Why was the originial computer replaced?

 

I don't know why the original computer and all the wiring was replaced before i bought it but the computer i had replaced was a mistake made by the local dealership who thought it was the problem when my car was dying when it was a hole in the air bellow boot. They thought that because they could not read any codes from the plug that it was a fried ecm so they replaced it and that was not the fact so i got stuck with a 300 dollar ecm for nothing.

 

Sounds like the problem is happening once it does the open/close loop switch. Possible bad O2 sensors as those readings will control the gas/combustion isues by the ECM. opti is another poss, although that would probably happen all the time.

 

I had the exact same problem with my 93. It will only get worse. Turned out to be the optispark. Called jason Cromer and $280 later my car runs perfect.