Big Al

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95 Z-28. Seems to be lean. Has Walbro pumps in the tank, only running one. Wondering why the ECM is running it too lean. Any idea what to look for or where to start? I'm going to try pulling codes tomorrow but this thing is such a mis match of parts I don't know if it will help. At least I may be able to watch the injector pulse width and monitor the O2 sensors.

Really need a crash course on tuning this thing....

Al

95 Z28, TH400, S-60 w/4.30's

Old Geezer

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The fuel psi is??

Big Al

iTrader: (1)

Well that took a while. Fuel pressure engine off is about 47 to 48 PSI. With manifold vacuum it drops to about 40 PSI.

Drained all the old gas out of it yesterday, changed the fuel filter and then did the test.

This car is new to me and is kicking my butt. Tried to pull the codes yesterday. Hooked my OBD II scanner up to the OBD II connector and spent about an hour finding out it's OBD I. My OBD I scanner has the older GM connector so I'm screwed there too.

Need to get up to speed on this ECM ASAP. In the car is a cable with some sort of interface, fits the OBD connector and has a USB plug on the other end. Looks like a large RS-232 or old Centronics printer connector on the interface where the OBD cable plugs in. So I have a new quest, find out what it is and if it will work with the software that's available. Naturally there is no name or logo anywhere on it.

Tonight, lean or not, it's going to the strip for a shakedown. I'm expecting it will shoot ducks all the way down the strip.

Al another old guy.

95 Z28, TH400, S-60 w/ 4.30's <Thanks Carl>

jim ravencraft

Hi,
you can borrow a scanner from oreilly/autozone and others.
Remember running to rich/lean can cause major internal issues....
Tweak the tune prior to all out passes. 4.30 gears equals alot of rpm's.
Not much room for error........good luck and have a blessed weekend......captain jim

Big Al

iTrader: (1)

As forecasted it shot ducks all the way down the track, worse above 5,000 RPM. Ran 12.77 @ 106. 60 foots were in the 1.8's. Well I tried

Off the try to learn how to tune it.

Al 95 Z28, with optional miss....