3stangs

ok so i bought a 90 coup real cheap because guy couldn't get her to run at all. I retimed car but it was not getting fuel. I bleed the fuel line and the pump started working and car ran fine. all day long car started with no issues. The next day the fuel pump would not come on again and the fuel line was dry this time. I installed a new fuel pump and it worked and car ran fine. again all day the car would start fine. The next day the fuel pump would not come on again. Only thing I can guess is something electrical. when car did run i noticed an ark sound from under dash every time pump engaged. checked under dash and found a sidewinder alarm system. I know they come with a starter kill but my car turns over fine. could it have a kill to the fuel pump? Could it be something else?

Sidewayz6.0

Did you try grounding a jumper wire from the diagnostic connector?

3stangs

no i didn't.... what is the diagnostic connector and where is it? What will this do?

Sidewayz6.0

The diagnostic connector looks like a brown plug about 2 inches wide on the driver side, right behind the shock tower. You'll have to google this, as I don't recall which port is the fuel pump...(I vaguely remember it being a pink wire)

Anyway, stick a small wire into the port, and ground it. It will bypass the relay, and run the pump.

3stangs

thanks man! I will let u know how it goes . its storming bad so gotta wait till tomorrow

3stangs

ok so if the fuel pump runs after the bypass do i need change the relay?

3stangs

Ok so i did what you said and with the bypass the pump ran. So now does this mean I need to replace a relay?

3stangs

well i bought the fuel pump relay that is located under the driver seat . when i installed it i found it had a toggle switch on it. somebody must have had the same problem. if i flip toggle the fuel pump will consistantly run. after it ran a little i switched it off and the pump ran without useing the switch.

Sidewayz6.0

Usually if it runs bypassed, then the relay is bad. However, I ran into that same issue, and replacing the relay didn't solve it. After I chased it for about a month, I just hot wired it, and put it on a switch. However, I don't daily drive it. It hasn't been a problem.

mattdel

Relay operation is controlled by the PCM. If it's wonky, the PCM is probably bad.