Porsche 928 fuel pump

[aln928]

Driving my 928 today and the power suddenly stopped and I coasted to a halt,Tried starting but seemed to be no fuel getting through,called the AA and they reckon as I do that the fuel pump has seized or the other alternative may be the fuel filter or both.
Has anyone fitted or had one fitted and rough idea of cost.

Edited by aln928 on Sunday 3rd April 11:05

[Angelus]

I'd start with the relay in the passenger footwell. You can swap it with one of the others that is the same (I think there are a few the same) to see if it starts? Most 928/944 drivers carry a spare in the glovebox. Come back once you've tried that and we'll see what else there is.

[marks3drtaz]

Likely that the internal pipe from the intank filter to the scavenger pump has broken up and been sucked into the main pump, Very common as the 928 gets older. You can do away with the intank pump as it generaly not required in this country and make a new pipe with a general gauze filter on. Be very careful with the large nut when removing the intank pump as this can damage the tank by breaking the internal sleeve in the plastic tank.

http://forums.rennlist.com/rennforums/928-forum/25...

This link will give you an idea. Or as already said could be the relay or the LH unit. Best of luck

Mark

[barchetta_boy]

If it is the pump theyare about £120 from GSF

[aln928]

Angelus said:

I'd start with the relay in the passenger footwell. You can swap it with one of the others that is the same (I think there are a few the same) to see if it starts? Most 928/944 drivers carry a spare in the glovebox. Come back once you've tried that and we'll see what else there is.

Angelus
Any special tooling required or technique required to remove the relays as they seem to be solid?

[Angelus]

aln928 said:

Angelus
Any special tooling required or technique required to remove the relays as they seem to be solid?

There is, somewhere on eBay, but you would wait days on that. I would disconnect the battery, in case one shorts and be careful. Mine came out quite easily, rocking it from side to side. They're only about £5. The relay chart is on the underside of the cover. My 1991 was either 25 or 26? Check the horn works, if so use relay 16? I think, to replace it with. Keep us all posted, and you should get it fixed.

[barchetta_boy]

aln928 said:

Angelus
Any special tooling required or technique required to remove the relays as they seem to be solid?

Slide a piece of stiff packing tape such as that used to secure a large parcel under the relay. Pull up gently with equal pressure on both sides or rock gently from side to side. Do *not* use a metal tool to force it off.

Joel

[aln928]

Angelus said:

There is, somewhere on eBay, but you would wait days on that. I would disconnect the battery, in case one shorts and be careful. Mine came out quite easily, rocking it from side to side. They're only about £5. The relay chart is on the underside of the cover. My 1991 was either 25 or 26? Check the horn works, if so use relay 16? I think, to replace it with. Keep us all posted, and you should get it fixed.

Angelus
I have tried what you suggested ie:removing one of the relay's and swapping with the fuel pump but still it will not start.The engine will eventually run but only for approx 10secs and then dies.It barely reaches 300rpm.I have ordered 2 new relays from Porsche and will try again late tomorrow,failing this I think it will have to go to a specialist within the Glasgow area.

[stratfordshark]

You need to work through things in sequence.

Are you getting spark when cranking (use in-line plug tester or just ground a plug against engine)?

Is fuel pump running? Pull fuel relay and use a jumper to bridge contacts 30 and 87 on panel. Can you hear pump whine?

Once you know whether you have fuel or spark problem you can work through more detailed alternatives. Note there are 3 relays crucial to 928 running though fuel pump relay most likely to fail as switches most current. the others are the injection (LH) ecu and ignition (EZK) ecu relays. They all use the same simple type same as horn relay, though EZK relay incorporates a fuse tester.

[Angelus]

aln928 said:

Angelus
I have tried what you suggested ie:removing one of the relay's and swapping with the fuel pump but still it will not start.The engine will eventually run but only for approx 10secs and then dies.It barely reaches 300rpm.I have ordered 2 new relays from Porsche and will try again late tomorrow,failing this I think it will have to go to a specialist within the Glasgow area.

I wish I'd looked where you are before now. My 928 is just back from George Morrison in Rutherglen, a few 928 UK guys use him, there were 3 in with mine. He impressed me with his knowledge of the car. I would take it there if I had your issues and didn't feel confident. Stratfordshark has given good advice if you want to continue trying to fix it yourself? It is sounding more like fuel starvation if it will start but not rev.

BTW we are having a Scottish 928 meeting just outside Biggar in July if you would like to come.

[deadslow]

Also recommend G Morrisson in Rutherglen. He looked after my S4 and the thing never missed a beat. Very smart guy and nice to deal with.