What triggers high voltage to the fuel pump? (1 Viewer)

[IoN6]

I have noticed that on my '93 the fuel pump only gets 12+v at start and right after shutting it off. No amount of acceleration or long pull will the relay kick it up to 12v.

I have replaced the relay and the resistor checks out. If I pull the pin to the ECU and ground it, it will get 12v. So it would seem that whatever is supposed to trigger the ECU is not functioning.

 

[BILT4ME]

I have noticed that on my '93 the fuel pump only gets 12+v at start and right after shutting it off. No amount of acceleration or long pull will the relay kick it up to 12v.

I have replaced the relay and the resistor checks out. If I pull the pin to the ECU and ground it, it will get 12v. So it would seem that whatever is supposed to trigger the ECU is not functioning.

Start looking into temperature senders. That's what makes it go from open loop to closed loop.

 

[IoN6]

Appears it is >3000rpm and a decent amount of throttle. After checking the readouts on the TPS it looks like it is getting 12+v now.