GM ECM TBI Questions

[Terry Martin]

JET wrote:
> 
> Hi,
> 
> I changed a 2.8L to a 4.3L both TBI in an 1988 S10 4X4, but I can't
> make it run.
> 
> There is no check engine light at all.
> 
> I have spark, but no fuel. Can anyone give me a hint on where to
> start.

I would hazard a guess, in the absence of information, that your EROM or
ECM has not been changed or you swapped EPROM's between ECM's. A "VATS
circuit failure" can be read as a "Fuel enable failure", without setting
a trouble code or producing a dash light. Typically, from my limited
experience, swapping EPROM's simply results in a "PROM failure" code of
one type or another. 

The checksum of the EPROM should be validated, and given a valid EPROM,
it sounds like you have the ECM out a VATS equipped vehicle. I think the
EPROM check is done from internal ROM, and I know of at least one
vehicle in which a VATS fault resulted in no crank, no fuel, on a VATS
fault, which set a "fuel enable failure" instead of a VATS fault.

That's a start, although I can think of a dozen other places to start.
Electronics and gear-heads like me clash.

Terry Martin