Hi
I have a 99 GMC Jimmy 4.3 CSEFI. It will not start. But it will start if I add gas to the air intake. (I know not ot smart.) I changed the fuel pump, fuel filter. Regulator on meter body. I was going to start changing the injector but thought I would just see if they would squirt fuel. None of them do when you crank engine. Of course the intake cover has to be off to do this. Finally I got a new pressure gauge mine has been broken. I thought since I had pressure at the check point it was ok and I had a new fuel pump. Well I don't know if this can be it or not but I only have 41 psi key on engine not running. Book says 55 to 61psi. What can be the problem? It will run when I start it with a boost of fuel. no code come up. doesn’t run great. Any suggestions? any way of checking the injector? Should they not spray if I crank the engine (coil unplugged)? HELP before I pull out what hair I have left.
Thanks
Tim

 

Well you need 50psi before the engine will run although it seems that you've done what is nessessary to make that happen.
You may have installed a faulty regulator or you have a restriction in the fuel line somewhere .

 

can a fuel pump be waek or could it be a wrong one. Should I try the regulator first.
What is the best way to figure out which part it is? Thansk for all your help
Tim

 

To rule out anything in the intake, I would pull the fuel filter off and connect your fuel test gauge to the pump side of the fuel line.