A few years ago I installed some performance parts on my '92 GT. It runs great, and has the power I was looking for, but it seems to have develpoed a slight issue. I rarely push the car hard, but every now and then I like to take it up a little past 5,000 rpm just to see what it's got. Well I have noticed that there seems to be a skip or sopme sort of miss when the rpm's go this high. It is fine when driven below this rpm level. My first thought is was the AFR valve springs. I unfortunaltey did not upgrade the springs when I purchased the heads. Another thought may be too much fuel. Here is a list of parts currently on the car that may help someone diagnoes this issue:
Stock 77,000 mile short block
AFR 165 pedestal monut heads
FRPP 1.6 rr
TFS Stage 1 cam
Tmoss ported Cobra intake
PMAS 80mm MAF
FRPP 65mm TB
FRPP 30 # injectors
Kirban AFPR
FRPP 190 lph pump
The oldest upgraded part has around 4500 miles on it, and that would be the heads and intake. I know the injectors are too big for this combo, and I may switch back to 24#'ers soon. Could too much fuel cause this issue? Can I tell by pulling the plugs and inspecting? Let's say the valve springs were the correct pressure for this cam, could an incorrect size push rod cause this? I had a bitch of a time shimming these things, (Why did I not get stud mount heads?????)!
If anyone can help, it would be appreciated.
Stock 77,000 mile short block
AFR 165 pedestal monut heads
FRPP 1.6 rr
TFS Stage 1 cam
Tmoss ported Cobra intake
PMAS 80mm MAF
FRPP 65mm TB
FRPP 30 # injectors
Kirban AFPR
FRPP 190 lph pump
The oldest upgraded part has around 4500 miles on it, and that would be the heads and intake. I know the injectors are too big for this combo, and I may switch back to 24#'ers soon. Could too much fuel cause this issue? Can I tell by pulling the plugs and inspecting? Let's say the valve springs were the correct pressure for this cam, could an incorrect size push rod cause this? I had a bitch of a time shimming these things, (Why did I not get stud mount heads?????)!
If anyone can help, it would be appreciated.