Well I will start out by telling you the symptoms. this truck is not daily driven and now that i have went back to start it up it is having fuel issues.
When i turn the key to ACC. once in a while the pump will prim. After that there is no chance it will prime
I can manually put power to the pump it is still good. I have checked all grounds relay battery pump, not ecm yet but i can bet it is a great ground.
On the firewall there are 4 relays mounted, the hanes manual says that 3 of them are for the ac which is incorrect cause i went threw them and put individual power to certian wires for running lights and other stuff to come on. so i think one of them is ac one is fuel pump one is oil something. and other running lights.
I am not 100% positive which one is the fuel pump relay but there is only one 5 wire relay and the manual says it has 5 wires none of which is color coded according to the book.
when the ignition is on the relay is getting no acc power. Is it suppose to be a 2 second momentary or ?
this is where im stuped.

i have read alot of forums on this and cannon figure what it is. I have been told it could be a bad computer or ignition module.


How could I test the 2?

Welcome to AF

What year?

When it acts up do you have spark to more than one spark plug.

Does the fuel pump run when cranking the engine?