1991 GMC 1500 Pickup Q&A
1991 GMC 1500 Pickup Question: HELP! HELP!! I still can't get this truck to start....
I hate to resort to replacing parts without testing them to now they are defective. It becomes inefficient and expensive. You have replaced so many of the fuel system components but it requires the computer to see power at the computer, and inputs from the ignition switch and the computer needs to see that the engine is cranking or running to power or trigger the fuel injectors. You need a wiring diagram and a Volt/Ohm/Ampmeter to do testing at the computer to see that the computer is seeing power ,ground, inputs, processes this information, makes decisions and controls out puts. - patrick mannion
my truck is a bit newer,but same problems,replaced lots of sensors,pump,etc..try oil/fuel pressure sensor/switch..crankshaft position sensor - gov
check your fues links on the fire wall a fues link may be bad and not allowing a sig to the ecm .also check the ecm ground and the engine ground these are the life line to the ecm. also was the ecm burnt to your car if not that is your problem . - Visitor
did you put gas in it - Visitor
it has a crank sensor problem, it is behind the crank pulley. - 91gmc
Recently my truck has been shutting off shortly after starting it up. All of my gauges read wrong when this happens. My battery says it's only a quarter of the way charged, temp is all the way in r...