frustrated

I was told that it wouldnt run properly with the pump relay bridged if it was that. Was he wrong?

frustrated

What am I looking for with the pumps? over current? resistance? lack of resistance? does anyone know what readings I should be getting?

the flyin' scotsman

I'd just confirm whether there is or not an internal pump.......it jams as the hose disintegrate internaly. You mention a new external pump, pieces of the hose could be in there also and the filter.

If this is the case that may cause the the over heating of the relay/LH and subsequent shutdown.

We can easilly rule this theory out if you take the cover off the fuel pump and look at the location pictured as well as checking the fuel pressure.

Once we confirm/deny we can move on............(why would a bad CPS/wiring cause the fuel pump relay to overheat?)

928GTSM

I bridged the fuel pump on mine to ensure it was getting fuel and it still wouldn't start because with the CPS failing no matter how much petrol you push through there's no spark to ignite it.
I didn't have any issues with my fuel pump relay getting hot and other weird noises so it's more than likely you've got a different problem. Hopefully your on the right track though with getting your ECU to John to test.

frustrated

Thanks guys. Yes once John confirms the ECU is ok (or not) will hit the pump/pumps. but will check where the fuel immobiliser connects to first. hopefully its on the relay side of the ECU which would only leave the pumps, ECU. or ground resistance. I think. Will keep you informed.

frustrated

Ah! John has found something wrong with the ECU. Hopefully that is the only cause and not something underlying which has made the ECU fail. Will know Thursday. But will still check the pump. its not completely RIGHT so I think an overhaul and new filter at the very least. Its handy having breakdown cover! I think the company will think again before giving it to another 928 owner!

auzivision

Doesn't the fuel pump have some sort of circuit built in that shuts it down so it won't overheat?

Anyhow, your symptoms sound exactly like what mine was doing down at SITM last year... a new fuel pump solved the issue.

Maybe your 12 month old pump is just a dud.

frustrated

Yes I'm thinking along the same lines. I have only got an external one (checked this morning) and It was an aftermarket pump! So as it is covered I shall go get a nice shiny new one.
Thanks for all the input people. It is much appreciated.