Join Date: Sep 1999
Location: Vancouver, Washingon
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Re: 350 TBI on a 351W
The GM TBI system will control both the fuel injector pulse rate and ignition timing curve. You have hit the nail on the head when you describe having the GM Engine Control Module (ECM) control the ignition timing curve as being the #1 obstacle! The best bang for the buck and the many hours of labor involved for a non-GM engine TBI conversion is to get the GM ECM to run closed loop. The GM ECM has some ability to learn the engine parameters of a non-GM engine if the engine sizes are close in displacement, called the "block learn".
If I was to convert a non-GM engine to TBI, I would make things as simple under the hood as possible. In my local emission test area, I'm only required to pass a tail pipe emission test. So most every non-GM emission part under the hood would hit the landfill, except the fuel vapor system which I would have the GM ECM control. I would landfill the EGR system, and exhaust AIR system. I would keep the non-GM PCV system. I would keep the Ford temperature and oil pressure sending units for the dash instrument panel, and add all the GM TBI sensors so I could run closed loop. I would also install the GM electric fuel pump safety systems, like an oil pressure safety switch to shut off the electric fuel pump if the engine should stall in an accident. I just don't understand why some people will spend $$$ on a fuel injection system, then in ignorance, not provide themselves a simple fire safety device because they can't figure out two wires.
Doing the conversion is not going to be easy if you need to learn how a GM TBI operates. If you know the GM TBI extremey well, it's an easy system to adapt to a non-GM engine.