So I have a 1994 LT motor, it's PCM, and the complete uncut engine bayharness from the donor car. Does anyone have tips on where I need to look to start figuring out how to cut this harness down to just what I need to run the engine? Also it's a PCM and harness from an automatic car and I'm going to be using it with a manual trans if that makes a difference.
I have the factory fsm from a 95 Caprice that I could send pics of. Not sure if there is much difference between 94 and 95, as they were both OBD1.
In reply to Appleseed :
Supposedly 94 and 95 were the same. I would greatly appreciate those pics. PMs usually work well for me. If they don't my email is daylan(dot)chapman(at)live(dot)com
Generally speaking to make a gm run you take all the oranges off the fuse block plug to battery and all the pinks to ignition switched power and the blacks to ground. Was there vats? Might need a resistor off the ebays. Should be relatively straightforward. The pcm was up front left and the fuse block is right fender well by firewall. From pcm some stuff goes into the car like speedo signal and gauge stuff, but that's all ancillary bs you don't need for it to run.
I have a 93 corvette Lt1 installed in my 34 Ford Roadster, so it was just stand alone when I ran the factory ecu. I don't think there is much difference with the automatic cars as they ran 700R4 transmission and that does not talk to the ecu.
Start with the following
Injectors
TPS and IAC
Coolant temp
Inlet Air Temp
that should have a map sensor
there is a plug that goes down to the optispark and another to the coil ( not sure if yours has it but I would highly recommend changing to the vented opti cap)
I think the factory ecu has a low oil pressure cut off so I think you need that
fuel pump relay control
not sure how the factory harness was wired but I had to make a fuse block for the power side of the fuel injectors.
Not sure what you are using for gauges, I just ran a regular set of gauges and skipped the electronic dash
Hope that helps get started
I put a 94 LT1 into my El Camino with a manual trans and automatic computer. Didn't seem to mind at all. I did use a Painless Wiring harness as I didn't have a GM harness with the engine.
Subbed!
Super simple on the manual thing... Just reflash it for a T56 application and it completely ignores the transmission entirely.
Speedo sensor is just for the speedometer and for controlling an automatic. It doesn't do anything for engine management. I used to know a ton about it, but it has been a while.
Suggestion: Contact Bryan Herter at PCMforless.com. He is the LT1 tuning wizard.
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