Boxster fuel pump not working

[Bob L]

I purchased a barn find 99 boxster. We got it running but only between 4 & 5 thousand rpm. We trailered it back to my shop. I started by cleaning the fuel system. Drained the fuel and replaced the filter,bench tested the pump worked fine. Put everything back together, would not start no fuel going to the filter pump not running. Fuses ok used a jumper wire on the fuel pump relay pump still not running. any ideas. Thanks Bob

[Marc_986]

I'd starting by tracing the wiring and check for voltage. Is there 12v at the pump? relay? fuse? etc.

[Bob L]

Thank you. I have done all that.

[Bob L]

does the computer under the driver's seat control electrical to the fuel pump. Thanks Bob L.

[Bill Ladd]

The box under the seat is the Immobilizer. A wet, failed unit causes no-start conditions, remotes not working, windows or locks not working, alarm going off randomly, etc…

Needs ECU/immobilizer repair & reprogramming or replacement.

There’s a lot written here about it and elsewhere.

[JFP in PA]

Originally Posted by Bob L

does the computer under the driver's seat control electrical to the fuel pump. Thanks Bob L.

Yes........

[Pringle86]

If the pump bench-tests good, I would check for 12V and a solid ground right at the pump connector while cranking. If you jumpered the relay and still got nothing, either the jumper pins aren’t correct or there is no power feed to the relay/pump circuit. Also worth scanning it, since an immobilizer issue or no crank sensor RPM signal can stop the DME from running the pump.