Injectors
Thread Starter
Racer
Joined: May 2009
Posts: 364
Likes: 3
From: merced ca
Injectors
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???
Le Mans Master
Joined: May 2006
Posts: 7,708
Likes: 266
From: indy indiana
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
Race Director
Joined: Aug 2000
Posts: 11,470
Likes: 763
might as well check the fuel pressure while you're at it...
Melting Slicks
Joined: May 2010
Posts: 2,082
Likes: 3
From: Conowingo Maryland
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
Thread Starter
Racer
Joined: May 2009
Posts: 364
Likes: 3
From: merced ca
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.
Melting Slicks
Joined: May 2010
Posts: 2,082
Likes: 3
From: Conowingo Maryland
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
Thread Starter
Racer
Joined: May 2009
Posts: 364
Likes: 3
From: merced ca
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.
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Thread Starter
Racer
Joined: May 2009
Posts: 364
Likes: 3
From: merced ca
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.