Fuel pump won't energize with key after it sits for three days or more. If the car is started more often it starts and works fine. Put in new fuel pump relay and have had mechanic check wiring and replace ignition switch. He suggest wiring a switch to energize it when needed but that seems cheesy.

 

Why dont u find where the problem is?

Put a fuel pressure guage on it, block the return and feed lines and see if it holds pressure. If it holds pressure, release the clamp on the feed line and see if the pressure drops. It will tell u whether the injectors are leaking down or the check valve in the pump is bad.

later
Jeremy

 

You're saying the pump won't prime when you turn the key on after the car has been sitting without being started?

 

Apeiron that is exactly it. Any ideas? 3.8 thanks for the idea, the car is currently in Colorado and I am in Wisconsin trying to give my mechanic ideas.

 

What kind of shape is your battery in after three days?

 

Battery is very new and cranks the car very well. The fuel pump acts like it is not getting the signal after it bleeds down.

 

If you don't have an electrical problem supplying power to the pump, then it sounds like its time for a new pump.

 

I think that may be it, it just sucks so bad to it, I did one in my last car. I want to be sure before I did it again. Is that Petronix one the best one to get?

 

I haven't read here anything about troubleshooting the fuel pump circuit. Is the mechanic sure that the fuel pump is not getting power? Has he checked the tan/white wire on the fuel pump relay for voltage during the 2-second fuel pump prime?

There is more to the fuel pump circuit than the relay.

Has the mechanic checked connector C313 above the differential?

Lou