im working on this truck for my neighbor, and on a small budget.

Its a 93 gmc jimmy 4.3 vortec 4x4

The only way to start it is to spay a good amount of starter fluid into the throttle body. Even then you have to have it at wide open thottle to start. Once its running, its very rough, it will idle and rev fine. But quite shaky like a misfire.

I was thinking fuel pump may be bad, but i hear it prime when i turn the key to on. Not sure how you check the fuel pressure.

Today i replaced the fuel filter, cleaned the throttle body and sensors.
Did not help at all.

Any ideas????

 

Starter fluid and WOT to start it are contradictory. Have you tried just cranking at WOT?

You need to do a fuel pressure/ leakdown test. Do a search on DIY folder for directions

 

Lol... i just found out its a tahoe, not a jimmy. Has no emblems.
Anyway... This thing is a major rust bucket with 410k on it!!
Im not getting to deep in this project, just trying to help a neighbor.

I used a small flat head screwdriver to open the test valve just to see it would spray gas. It didnt, so now im thinking it is the fuel pump.

 

It could be the pressure regulator. Put a fuel pressure guage on the service port and kink the return line. cycle the fuel pump a few times and see if the pressure jumps up. if it jumps up when you kink the return line and goes down lower than 45lb with the line unkinked, then it is the regulator. if you get little to no pressure with the return line kinked, either it is out of gas, the fuel pump is bad, or the rubber hose between the pump and sending unit is broken and leaking. Also, with the fuel pump running, pull the small vacuum line off the regulator and see if it is leaking gas- if it is- then the regulator is shot.
hope this helps...