Starts then dies, with a twist.

[Blood of a Jeep]

4.0 ax15 1990 2wd. Ok so like the title says. truck starts then dies did some research and now i have a question. On the fuel pump relay there is an orange wire with a black tracer. Where oh where does this wire go? Ive searched, Ive researched, I'm comin up short. 

[Stacks]

It should go to the fuel pump ballast resistor on the driver's side fender well and then on to the fuel pump.

[Blood of a Jeep]

Erm. Maybe the ballast resistor. But the fuel pump is the solid orange wire. In all the diagrams Ive found, the orange with tracer leadsto the computer. 

[HOrnbrod]

Invest in a 1990 FSM.

[Blood of a Jeep]

Yup. I just verified it indeed goes straight to the ecm. 

[Blood of a Jeep]

I figured it out. The truck had a bad ecm. Whoever worked on this thing before me got so lucky with what they did.Basically we all know the fuel pump relay has four contacts. One is ground from the ecm, one is power from a fusible link, one is the fuel pump and the fourth is a trigger i believe. So what they did is added a wire from the fuel pump at the tank on tue power leg, then they hooked that to the ecm ground leg. For some reason the ecm ground was outputting 12 vdc. So that went down the added wire hit the pump, then back fed up the original power wire to the fuel pump. At the relay i believe it was enegizing it backwards. Allowing the truck to get spark and run. Crazy.