kitttransam

So I've been racking my brain lately about how my 89 runs. Just doesn't seem right. Mpg isn't too great either. I do have bosch III's. I put em in when I built my motor. Engine was dead when I bought the car. So read a few post about some peoples l98's running lean with the bosch III injectors. Any suggestions? Motor does have a zz4 cam and flat top pistons. Other then that motor is stock. Maybe need bigger injectors???

ghoastrider1

first thing is to check the timing and for vacuum leaks. I had a SS396 chevelle that started to run flat..drove me crazy..finally figured out it was a flat lobe on the cam and several others wore down. good luck

Joe C

might as well check the fuel pressure while you're at it...

kitttransam

I do have an AFPR and have tried different fuel pressures. Never had a problem with fuel pressure even with the stock regulator.

hooked073

how did you measure fuel millage? Seems right is hard to tell on a comp. If you think it is low on power I would check timing, be sure you disconnect the timing set wire, Also I would check to make sure the exhaust is not starting to clug up

kitttransam

I've measured both manually and gone by the comp. pretty close surprisingly. Exhaust was already replaced for that reason a long time ago. Timing is set at 6. Maybe I need a tuned chip for the cam and flat tops.

hooked073

Atune might give you a little but I no not think it will solve the problem you are having. You are asking for almost the impossible when we caanot feel what you are. Have yoou put a vacum gauge on it? I would do that and post the results on here

kitttransam

Vacuum is good it was around 15, green area of the gauge. Unfortunately I don't have all the diagnostic tools I need to check everything out. My dad does. He's got an autoxray. He said I could hook that up and see my air fuel ratio is in check.

kitttransam

Ok hooked up the auto X-ray. Didn't have a/f ratio on it but it had block learn (blm) read a lot about blm should be 128. I was at 114 meaning it was rich. Dropped fuel pressure fine tuned it while driving with scanner. Got that squared away. Now if I can just stop the pinging at 3/4 throttle.