1992 GMC Sonoma 2WD

General Discussion
1

I have a 1992 GMC Sonoma pick-up truck 2Wd rear drive with 6 cylinder 4.3L engine.My question is how to find out whether this engine is single port fuel injected(SPFI) or multiport fuel injected(MPFI).Don’t have Vehicle manual.

2

Your 92 Sonoma probably uses TBI (Throttle Body Injection) the main part looks like a carburetor and contains 2 fuel injectors.

The S in SPFI stands for sequencial fuel injection (lose the “P”)

There is a designation called “grouped single-fire port injection” and its class designation is MPI (Multiport injection)

Then there is the famous CPI or CMFI (central multiport fuel injection)which uses 1 injector and 6 poppet valves,perhaps this is what you are thinking of.

There is no system that I would call single port fuel injection. I guess a one cylinder fuel injected engine would qualify.