Porsche Enthusiasts Club Forum

Well I suffered my first breakdown with the GTS tonight, which was a sod as it had been running fine all day. I went out this evening to pop and pick something up, came onto a roundabout, round second gear and launched it coming off went to change into third and all of a sudden th engine died. With a great deal of embarassment I cost to the side of the dual carriageway and managed to ge tit off the road. Called a mate who thought it might be the fuel pump relay but whilst talking to him I tried starting it and hey presto it did. I gingerly pulled back on the road and away I went, all of about 1/2 a mile before it cut out again. This time it point blank refused to start.
my mate came ot and tried swapping the horn relay for the fuel pump relay but still no joy. He was going to tow me home but the socket for the towing eye appears to be completely buggered so I had to call a recovery company. I'm hoping it's something simple like the fuel pump but knowing my luck it'll probably be something expensive, doh!

It's actually convenient (hah - not when you were waiting for recovery!) that she won't start as easier to identify than intermittent problem.

Check whether it's fuel or spark-related.

John Speake has a handy 928 no-start troubleshooting guide here:

http://www.jdsporsche.com/fault%20find.html

It's a complete PIA as I asked the garage where my car was taken to have a look at it andthey said they had to clear a few jobs this morning but would look at it later. 12.15 pm I got a phone call saying we're not sure what the problem is as when we went to the car it started first time! So I'll check out John's troubleshooting tips and set about replacing the relays and likely as not one or both fuel pumps.

On a seperate note does anyone know if the front towing eye socket can be helicoiled or repaired without cutting it off and welding another one on, I never realised that there was nothing covering this and there was major corrosion inside it. So much so that I couldn't get the towing eye in and hence why I had to get recovered instead of getting a friend to tow me home. I rally need to get it repaired so if nothing else if something happens again I can at least get towed to safety even if I still end up needing a recovery.

I'm sure I read somewhere that you can get a tap, but they are a thread from a fire engine? I might have dreamt this, but think it happened to someone else. Turned out his bumper had slipped down after he done all the hard work of getting material. Try filling the thread with WD40 and cleaning out the rust, might get lucky.

BTW if yours is corroded, a Scottish winter coming soon is not going to do mine any good.

Any Pictures of the damage?

Well there was speculation that this may have been the fuel pump or a relay but neither appear to be the problem. The car will start and run fine for 20 mins or more and then won't start, or even fire, at all with apparently no spark at the plugs. Suspicion has now moved to there possibly being a problem with either the immobiliser or an ageing fuse board.
I dread to think how much it would be but does anyone know if a replacement fuse board is still available?

One possible cause is failure of the crank position sensor, which signals to the injection ecu that the engine is turning. If the sensor becomes intermittent then it can fail when it gets hot, then be ok again when cooler.

I am away from my copy of wsm but there is a procedure for testing output of the sensor, but only helpful for you when the engine has cut out. Easiest test is to get hold of a 'spanner' diagnostic reader from JDS Porsche and that runs a crank sensor test. Well worth having anyway as a big timesaver when troubleshooting and will save money in replacing parts which are in fact ok.

The tow eye is notorious for corrosion. A bad choice of materials on Porsche's part (probably same chap who specified the driving light bolts). There are some excellent threads on Rennlist describing procedure for drilling out the seized cover. Just puzzled because I thought the gts used a rubber cover on the eye, and didn't have this problem?

Stratfordshark unfortunately at some point the rubber bung has gone missing, hardly the sort of thing you notice unless you need it I suppose, what I really need is a tap of the right thread to try and re-tap it. I've tried a couple of local tool supply wholesalers but no joy so far, bit of a strange thread apparently, I'll have to look into the 'Spanner' that you've mentioned.

http://www.jdsporsche.com/jdsdiagtool.html

Link to the spanner.

If I had your symtoms, I'd have a squeeky bum! But as you have a manual you don't need to worry about TBF!

I hope you're back on the road soon, petrol is due to go up so get as much 928ing done before the end of the month.

http://www.jdsporsche.com/fault%20find.html

Sounds like you've checked all this stuff, but worth a read to double check.

Hi,

I've been had similar problems with my 944, First time after a weeks worth of head scratching in the garage an ECU replacement fixed it (£250 for a used one!), my recent prob was due to a faulty fuel pressure regulator. Your prob sounds more like my ECU troubles.

Rich

I shall check the crank position sensor first and gradually try a process of elimination to see if I can track this down as I don't really want to be driving a car that may let me down at any time. 'The Spanner' may have to go on the wish list as funds are a bit limited at the moment, I have to budget for a service but it's a bit of catch 22 as I need to be able to get the car there in the first place.

Well a friend of mine came round this afternoon and we ran the engine up to operating temperature and and shortly after reaching this as soon as you put your foot on the throttle everything died, the cooling fans immediately cut out and it would crank but not start. I have to say a big personal thank you to John Speake here as he was offering us advice over the phone on a Saturday when his good lady really hoped that he'd be left in peace to do some paving, thank you John.
With the fault 'live' we tried changing both the fuel pump and EZK relay's for a known good one with no joy, we then connected the fuel pump directly to a 12v gel cell battery and it was pumping like a good'un, cranked it over and it still wouldn't start. The next thing was to check for a spark so we pulled a plug and cranked the engine, oh bugger it started on 7 cylinders and the plugless cylinder spat out fuel in my friends face! We put the plug back and started it and let the temperature come back up (it had obviously dropped while we were fannying around with the relays and pump) and sure enough it cut out again. Straight out with a plug and cranked and no spark.
I shall order a crank position sensor and whilst I have located where this is I'd apprecaite anybody that know's telling me where to find the connector for it and if I have to remove anything to get to it? John did try to explain but neither of us could see where it went, we msut both be going blind!
Sorry for the long post and thanks for the advice.

Only experience I have with a crankshaft sensor is on a Mondeo. If it's faulty the car won't start as the timing is out. ie: It doesn't know when to fire up...

The crank sensor sits on top of bell housing behind engine, visible with airbox removed (remove intake tubes, top of box and filter, then two 10mm nuts hold base down).

It's held in by allen head bolt.

Follow sensor cable back to connector amongst a number of electrical connections under fuel pressure regulator.

The sensor can be tricky to remove from the top as it gets stuck and needs careful prying/turning to remove without leaving bottom half stuck above flywheel. Best to soak with penetrant for day or so. Costs around £120 I believe (it's shared with 944 and has 944 part number 944.606.115.00 so do run tests to see if it's at fault before changing. Porsche calls it a Pulse Sender.

Is it best to unbolt the fuel pressure regulator to get to the connector, I've had the air filter assembly off and I can see the sensor but failed in my attempt to trace the wire back as I couldn't see or feel where it went for things being in the way. John Speake suggested changing it anyway as they are prone to failure and it is more than likely as not the culprit. I don't actually have anything to test the sensor with but the fact there is no spark or fuel there when it cuts out suggests a loss of signal.