Thanks for the fuel line help guys.
This is a 1990 4.0 5 speed mj. The PO has put a fair chunk of new parts into it with no luck. New plugs, cap, rotor, wires, fuel filter, air filter etc. You know the usual shotgun method of problem solving. I received this truck as a non runner so I went in not really knowing what could be wrong. Reading and talking to some friends lead me to the CPS. By the looks of it its not a bad idea anyways so I changed it. Still nothing. More reading and poking around and I thought maybe the ignition switch. Pulled it apart and sure enough its very worn inside. So new one of those. This may have actually made an improvement. I can get it to run while in the crank position but not when releasing the key to run.
Are there some fusible links some where I'm missing. I've metered the fuel pump at the ballast resister and I have power for a second when I turn the ign on and during crank. This sort of makes sense, but why once its firing does the power go away. This isn't the complete issue as if I bypass this with a jumper lead the problem persists. What I'm wondering is what other circuits are not turning on in the run position?
Thanks in advance.
Eric