I just joined the site, so I may have missed previous discussions around the computer control problems with 928s.

Has anyone else had problems with the car just plain "shutting down" in mid-transport?

I am by no means an "auto expert". At this point, my girl is behaving (no stopping dead in mid drive). However, I would be curious to know whether any other 928 owners suffered the same experience, esp. after the car getting wet, etc.

Many thanks,
BE and her Trixie

 

I have (or hopefully HAD) a similar problem with my 84s where the would enigne cut out at any given time (like a busy toll booth for example!). In my scenario, I found I had spark but no fuel delivery. I then isolated it to the Jetronic control unit, as I was getting current to the fuel pumps. I popped the ECU open checked for burned resistors, etc. and plugged it back in to find the engine fired right up. Bad solder joint inside the ECU? well 2 hours worth of resoldering each component in the ECU seems to have done the trick (for the last 3 months at least).

Anyway....I digress, if it dies again, pull a plug to see if you have spark. If you do, then at least you know it's most likely fuel related. I believe your vehicle has Motronic engine management (fuel & ignition control). If it's more prevelent in wet conditions, sounds like a short or ground issue. not to sound obvious......

 

Welcome BEG and Trixie.

Was a passenger onboard at the time the car died? If so, it's possible that they were pressing their feet hard against the forward footwell area. Behind this lies the fuse/relay board. In this scenario, the fuel pump relay or fuse can become distorted within its connector, resulting in loss of power to the fuel pump, and the engine dying.

When the car died the passenger sits up in alarm, releasing pressure from the relay/fuse, then the car starts and runs OK after that.

Sounds bizarre, but it's happened to me before...

 

Blue Eyes,

Can you describe your symptoms in further detail?

When I had my 87S4, all of a sudden, it wouldn't hold a steady idle creeping along, then died as I came to a stoplight. Restart, drive a ways, then die. Repeat. Then crank, but no ignition.

Replaced the brain - once again a happy shark.

You might try resetting the brain by disconnecting the battery for 15 minutes or so, then reconnecting.

If you can afford to have the car down for a few days, you might consider removing the brain (lobotomy!) and sending it out for testing (e.g., to DEVEK).

If the brain is defective, be sure to get the latest revision (corrects previous defects).

Good luck.....

 

Some possibilites:
Bad fuel pump relay (XX)
Bad EZK (ignition) relay (XVI)
Bad LH (injection) relay (XXV)

Bad ignition switch (Try jiggling the key slightly if it dies again - be careful to avoid hitting the starter if the engien is still turning over!)

Your car has basically two independent ignition systems and two injection systems, so there are alimited number of "single point of failure" items that will totally kill the engine.

More clues (Do the gauges drop to zero? Do any warning lights come on while the engine is still turning? Do any warning lights come on after the engine stops turning?) might help with diagnosis.

 

Good suggestions Wally, but I think this person is one of those hit-and-run Board visitors - they post a question, then never return, nor post an acknowledgement to others for their assistance. In the words of Jar Jar Binks - "How wrood!"