Join Date: Aug 2011
damanx is offline
Re: 4.3 TBI Harness on a 2.8L
The TCC lockup from the computer simply locks the TCC when certain conditions are met. You could use the vacuum lockup, but it essentially does the same thing. I opted on my 85 to let the computer do it.
I've looked at the programming in a lot of BIN files and each BIN is different. I don't recall that there is a difference in the harnesses between the auto and standard transmission vehicles.
Also, if you have an '85, and, it has cruise control, then you already have a VSS. It is a little box up under the dash that has a set of wires going up to and attaching to the rear of the speedo.
*BIN file = programming in eeprom that tells the computer how the engine should be running at any given operational parameters set for that specific setup.
1985 GMC S-15 Gypsy ext cab.
3.4l, Edelbrock intake, a 4.3l throttle body controlled by an '88 TBI ECM. 700R4 with 3.73 rear. Real time tuning using a CF-30 Toughbook with a Moates Ostrich 2 emulator.