Non-starting 944 Turbo - any pointers?

Spongebob · Feb 23, 2016

1986 944 Turbo. Was running fine last week. Got in last night and cranked engine over. It fired and then died. Does this every time. Got in it this morning it fired and then ran for about 3 mins before dying again. Now turns over, fires and dies. Refuses to run.
I have a spare DME relay which i tried just in case and it makes no difference.
Any pointers as to where to look first?
Nothing visibly wrong or hanging off. Half tank of fuel and good battery!

white944 · Feb 23, 2016

Die kraftstoff pompe ist kaput.

Spongebob · Feb 23, 2016

was thinking that. Where actually is it on one of these?

Spongebob · Feb 23, 2016

Sods law. Turn on ignition. Can feel fuel pump running by placing hand under tank. Crank motor. Fired, settled to comfortable idle and remains running. Is the pump on the way out or could something else cause an intermittent problem? Should i replace pump to be safe?

Richair · Feb 23, 2016

Well if it's the original pump then it would be a good idea to renew it any way, so I'd start there personally... A new Bosch one is around £90 I think.

robwright · Feb 23, 2016

Fuel pressure would be my two penneth also.

vitesse · Feb 23, 2016

Could just be a bad connection at the pump hidden away within the rubber terminal sleeves-presuming there is still an external bobbin mounted pump on a Turbo

Spongebob · Feb 23, 2016

Bosch fuel pump from OPC Swindon.......£260!!! Even their parts guy couldn't believe it.

robwright · Feb 23, 2016

Where are you at? I have a good spare for an ummodified turbo. Not saying it is your solution but would at least serve as a test bed.

Spongebob · Feb 23, 2016

robwright said:
Where are you at? I have a good spare for an ummodified turbo. Not saying it is your solution but would at least serve as a test bed.

I'm Faringdon, Oxfordshire so not close but thanks for thinking of me . Porscheshop is substantially cheaper for OEM Porsche so might open the credit card to them. My car is modded but not hugely. Augment ECU, Tiall dual port wastegate, upgraded fuel pressure regulator. Was running fine on stock pump so dont think it needs upgrading to something like this:
http://www.ebay.co.uk/itm...its=Car+Make%3APorsche|Model%3A944&hash=item233d771cf2:m:mreeM6i4IQpYnhkO3_fNjTQ

DavidL · Feb 23, 2016

Mine runs very similar mods and has a stock pump so i'd say that should be ok. You aren't far from me or Mr Trasler, it should be a wilts/oxon modded turbo meet!

DavidL · Feb 23, 2016

Spongebob said:
Bosch fuel pump from OPC Swindon.......£260!!! Even their parts guy couldn't believe it.

They've got to pay for their new showroom somehow!

Richair · Feb 23, 2016

Euro Car Parts is your friend, they do an OEM spec Bosch pump for around £90.

blade7 · Feb 23, 2016

Fuel pressure regulator.

944 man · Feb 23, 2016

robwright said:
Fuel pressure would be my two penneth also.

And mine, as it is the 'DME relay' of the current time.

Hearing the fuel pump running concerns me though, because it shouldn't run unless the engine is cranking, so someone has f*cked about with it, and they NEVER improve on Porsche's original wiring... This also means that immobilisers have been fitted, which again, is seldom a good thing.

bmnelsc · Feb 23, 2016

DavidL said:
Spongebob said:

Bosch fuel pump from OPC Swindon.......£260!!! Even their parts guy couldn't believe it.

Click to expand...

They've got to pay for their new showroom somehow!

According to either Excellence magazine or Panorama magazine (P.C. America) article, Porsche is responsible for 25% of VW group profits (while being 5% or less of revenue). So just remember the multi-billion dollar line of credit VW established to deal with the fallout from the emissions test cheating ECUs the next time you empty your retirement fund to buy a few Porsche parts. Here in Canada, all our parts come via the US so we "enjoyed" a 30% increase over the last few months as our dollar followed the price of oil :-(

9four4 · Feb 23, 2016

The things that stop a 944 Turbo from running, in order of most likely (in my experience) are.. DME relay, old alarms and immobilisers, crank sensors (aka speed/reference sensors), air flow meter, ...along with the above too, they are all correct..

Personally, I suspect you have an old immobiler that is about to die. Have an auto spark remove it. Its worth the hour labour it'll take him to remove it and you ca rule it out of future problems.

You dare not take it to a garage when it breaks down either. I took a non starting 944t to a "specialist" and told him I suspected it was an old immob'. First it was a new coil. No joy. Days later he says its the crank sensors, need to take g'box out to get them out.. big job. He does that, still wont start. Traces the fault to an old alarm. I get a bill for over £900 weeks later after much stress, waiting, false hopes and hair pulling.. after saying it I thought it was an old alarm all along.
Save yourself that hassle. Prevention is better than cure... Specialists.. phew, my arse.

Spongebob · Feb 24, 2016

Thanks for all the advice folks. Fuel pressure - brand new regulator fitted when performance mods done. Immobilizer - yes it has one of those really annoying ones that you have to touch a gizmo on your key fob to before it will start. If that's not set it kills everything though. Removal is on the list. DME - i keep a spare DME in the glovebox. I tried that first and no difference. It all points to intermittent fault with the fuel pump. didn't think of Euro Car Parts so thanks for the prompt. Porscheshop is £160 for Bosch pump.