I have a 91 GMC 2500, 5.7L. was jumping our dump truck a few weeks ago and it just died, I figured maybe it ran out of gas - but it didn't . I knew the fuel pump was on it's way out(hard to start in winter) so I replaced with a 96+ fuel pump, tossed on new filter and relay, fuse good. I'm getting high volume at the feed line at the throttlebody(cannot find a schrader valve to test pressure). I couldn't get the return line loose at the throttle body, will keep fighting with it when weather permits.
I don't have a noid light for the injectors, I can't tell if they're firing during cranking
the truck will run off starting fluid so the spark is working
the injectors have a good 12v signal with key on - again, unable to test ground while cranking
both injectors will fire with a 9v battery but no gas comes out
the temp sensor is like 2 weeks old
I'm thinking, either a blockage in the throttle body casting(is that common?) or I read somewhere the ecu might not be getting the right signal from the distributer and I could run a new line from the dizzy to the ecu(wherever that is). not sure if that's worth looking into or not
truck's been rock solid for years - now I'm lost
I don't have a noid light for the injectors, I can't tell if they're firing during cranking
the truck will run off starting fluid so the spark is working
the injectors have a good 12v signal with key on - again, unable to test ground while cranking
both injectors will fire with a 9v battery but no gas comes out
the temp sensor is like 2 weeks old
I'm thinking, either a blockage in the throttle body casting(is that common?) or I read somewhere the ecu might not be getting the right signal from the distributer and I could run a new line from the dizzy to the ecu(wherever that is). not sure if that's worth looking into or not
truck's been rock solid for years - now I'm lost