Porsche Enthusiasts Club Forum

After buying my 944 a year ago one day it decided to cut out every few minutes or so, so I went through everything and never found out what was causing it then it decided to just go and has run fine ever since. I have had other electrical problems like the passenger window stopped working, the voltage meter stopped working and then the sunroof stopped all at different times but all started again soon afterwards so god knows what is causing it. Anyway went to work on Friday came home parked on the drive and all fine. We were going to the Porsche shop on Saturday and been a nice day I took the roof out and put it in the boot went to start it and it wouldnt start so I took the roof back out of the boot and slammed it shut and it started so put the roof back in and drove to Halesowen got the bits they had for me and drove about half way home and it stopped so I restarted it and went about 100 yards and it stopped again this happened all the way home so I took it out Sunday and tried a few things but no its the same as a year ago. What I have noticed is that the ignition goes off when it stalls it wont bump start straight away you have to wait 10 seconds coasting and then it will fire up again for the next 100 yards also if you try to turn the key over straight away the starter just groans and the lights go very dim as though the battery is flat, any ideas anyone there great cars but Im sure its Christine disguised as a porker...

check earths, engine block and battery, as break down over time

As said, take a look at your earths first. Give them a clean, maybe change the straps if they are looking manky and brittle.

Also, check out your rotor arm. Many rotor arms produced recently are not that hot due to not being made of Bakelite like they used to be (Plastic is not a great insulator). Do a continuity test on your rotor arm. This problem has affected me once on a Beetle, and a Midget, and also on a mate's Dolly Sprint.

However, they always seem to be well made on a 944...

Do 944 suffer from the same problem as a 924? ignition switch failing??? Just a thought.

That is my thought actually, or dodgy connection in relay/fuse box.

I'm thinking ignition switch as well. I've heard of an increasing number starting to go over the years.

And the immobiliser if it has one. I'm a bit nervous about mine with it being 20 years old.

I'd guess the immobiliser, 10 second delay in restarting is clue

Mike

I know the Cliffords work on a timer like this. If it has a Cobra alarm, they need to be disarmed to even let the engine turn over.

How the Porsche immobiliser works Lord knows. Did they come with one?

Later cars were fitted with a Hamilton & Palmer alarm at the dealers,they are based at Kemsing which is a stones throw from where the SELNK group meet. Not sure when this started, I think about

Well the latest installment is as follows- checked the ignition and all is fine, checked the earth straps and all seem ok, took the worst ones off and cleaned them, checked the dizzy cap all clean, rotor arm all clean. I took it up the road and it ran fine for miles then I gave it a boot full and it died. Restarted fine so I sat and reved it on the side of the road at 4k revs for 20 seconds or so then blipped the throttle and the biggest cloud of white smoke appeared out the back so blipped it again and it smokked again so off I drove again and it went for the usual 100 yrds and stopped then it ran fine again for a few miles. So I brought it home and let it tick over on the drive where it ran fine, I have lifted the fuse box out and checked the wiring, had my hand up the back of the dash and shaken the crap out of the wiring but nothing so off I go again up the road and its stopped again by the time I get to the t junction.
I can only think of a few things to swap, the dme relay, ecu or coil unless anyone else has any ideas as im totally blanked out now. Can someone tell me what the dme relay actually controls I know about the fuel pump and did the 3 wire trick last time to no avail so thats out and also where is the brain on my model.
Cheers for all your help as this is really testing my patience and is heading towards an ebay item.

News flash, I read on Clarks about a guy who gave the ecu a knock and it failed so wouldnt start so I gave it a smack and now it will turn over but not start or starts but only runs for a couple of seconds so I`ll take it out tomorrow night for a butchers, a soildered joint I`m banking on

Have you tried a new proven DME relay ? they can be intermittent and can cause loads of grief.
I carry a spare !

Not yet im going to order one tomorrow but ill check the ecu aswell.

What's the progress on this?

Regarding the rotor arm, check it with a multimeter from where the carbon bush touches it to where it distributes the spark. I've suffered from one going like this on a VW Beetle 1200 (with similar symptoms to yours) with a brand new rotor arm. A mate of mine had the very same problem on his Dolly Sprint too.