87 4.9L 4spd. Fuel pump relay under the hood isnt getting a ground signal. I have it jumped so that it will drive but I don't want to keep going like that. Any reason the ecu isnt sending the trigger? I tried to read codes in the ecu but none are showing up. How do I test for a bad ecu?

 

You try to get codes and when you get nothing the EEC is bad. Or a fuse, fusible link, wiring. Test for the ground from the computer at the computer.

 

Do you know the color by chance? I am away from the house right now but have time to test it. Thanks for the help

 

It's the one you ground on the diagnostic test plug to make the fuel pump run. With the four on the bottom, the right one.

 

I guessed it was the tan with green stripe. If it is then no ground at the ecu

 

Yea, that's it.

 

So bad ecu then? How much will one of those run? Will the 302 & 351 auto or manual ones work?

 

Is there anything besides a bad ecu that would cause no trigger signal to the fp relay?

 

A bad ecm relay will keep the pump relay from pulling in.

 

Ecu relay is working otherwise it wouldn't run with the fp relay jumped. Right?