I have a 91 NA that is giving me some trouble. I posted the other day on the 6 ports not working. That is all fixed up now. Heres what happening still-

Car accelerates great until 5500-6000 rpm and then it just falls flat on its face. It is accelrating totally normal and pretty quick and it just falls totally flat. It has a very hard time reaching redline when revving the car in neutral. When I go over 6k rpm the car will start to miss.

Here is what I've done/checked all ready-
unstuck 6 ports that are working properly
replaced fuel & air filter
the secondary throttle plates are opening
the cats have been replaced with a Bonez race pipe
it has an apexi dual N1 cat back
checked the engine codes - i got a code for the port air solenoid
VDI valve works fine

so what the hell else could be going on here??

 

misadjusted TPS perhaps?

 

haven't checked the TPS I'll do that tomorrow.

Also I put in new NGK plugs and wires. I checked the timing and revved the engine while using the timing light. There were no misses evident in the igniton system with the light.

 

It's probably the TPS acting up, it's probably bad and is jumping around erratically

 

I figured out the problem!

It wasn't the TPS

I pulled the secondary injectors and the inlet filter screens are completely clogged. The injectors weren't working at all!! I have an extra set I'm going to put in tomorrow night. Got my fingers crossed that this is the end of the road!!!