Thread: 1989 350 w/Holley TBI tuning?

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Trouble code = 42, System= Ignition Control, Indicating= open/short/component failure. You said this has been taking care of correct? Also are ALLLLL of your grounding and power wires reconnected?


I also found on mine I had to actually drive it to get it to drive right so the computer could "learn" the new components.

Ceck with CFM Tech for a fuel pressure fitting and gauge if you need it. Also you do not need to buy a adjustable fuel pressure regulator. From the factory they are made non adjustable so people try to sell you adjustable models for 75 dollars. With a drill and a dremel and 2 hours of your time you can make the stock unit adjustable. Fuel pressure from the factory is Supposed to be 10.5 - 11. PSI (if I remember correctly)if you put a gauge on it it will actually be anywhere from 9 to 12 PSI. You may need to raise the fuel pressure which is not a bad thing. Doesnt mean you will be wasting more gas.




Here are some other places you can get info.
http://www.fullsizechevy.com/forums/...obd-i-ecm-pcm/

Look in the lower left hand corner the print in the yellow.
http://www.cfm-tech.com/GM_tbi_tuning_tips.htm