Bob in Socal

I am trying to chase down a fuel issue 1986.5
fuel in tank ( flows easily to pump) pump runs when jumpered but no fuel or pressure...
Thanks

Mike Frye

Hey Bob,

I think you need to confirm that the pump is actually running and running properly.

Just because it's making noise doesn't mean it's doing anything. With plumbing I don't know if there's anything more high-tech than just following the flow and checking along the way.

You said you have no fuel, that the pump 'runs' when jumpered but you get no fuel or pressure. I assume this means you're getting no fuel to the fuel rail.

Can you tell us what tests you've done in order to confirm what is and what isn't working?

Has the car been off the road for a while? Did it work and then stop working? Did it die while driving or just not start after sitting for a long time?

Lizard928

If you have fuel to the pump and nothing leaves it (confirmed but cap removal) then the pump needs to be replaced.

dogleg

is there any chance you have jumpered it with the poles reversed.the pump will run backwards but it will be just pushing fuel back into the tank.

NoVector

If you've confirmed fuel is making it through the fuel filter and the check valve isn't blocked, my money would be on the pump. 928 Spec has some good tests/tips at: http://www.928gt.com/Default1.htm (look under the tips/links heading).

James Bailey

Where and how are you looking for and measuring fuel ??? Just nothing going into the cylinders ?? Spark plugs dry ?

Bob in Socal

nothing coming out of the pump, I disconnected from filter
sounds like pump is fubar

Mike Frye

Yup, sounds like it.

Some people have confirmed this and bought some time on the side of the road in an emergency by momentarily reversing polarity on the pump and letting it clear itself out or get off of whatever is hanging it up but if it's clogged, then whatever is in it will just get back in later.

Best to replace with new, most likely it's original. 26+ years isn't too bad really.

Good luck!