PatrickP

Driving yesterday with the engine sounding great, all gauges looking good, etc. Suddenly, car just died. Turned over but would not start. Flat bedded it home. This morning, just for yucks, turned the key and it started. Ran for about 15 secs and died again. Thoughts?

athenian

Hello...read the replies on the post "non start, after 2 miles, temp. sensor?"...It seems that you're having a similar problem.

Tony

PatrickP

Thanks, Tony. I did read that post. My concern is that the engine was anything but "cold" when I started as I had been driving for about 40 minutes and then had only stopped for about 10. Regardless, I will probably give Ed's diagnostic tip a try. Still, any suggestions from anyone will be appreciated.

Patrick
'85 auto

pd'83SC

Patrick,
...sounds like the fuel pump relay to me...mine acted up similarly...I could almost time when it would cease functioning.
...good luck,
Patrick

Thom1

Hi Patrick,

This may sound strange, but it's true. My car died after going over some railroad tracks. It turns out the the mechanic who worked on it earlier left a battery terminal loose. Loose or dirty battery terminals can do it.

Donald

Patrick- Mine died under similar circumstances (warm, w/ a bump at highway speed). Early diagnosis was external fuel pump (replaced) then relay (replaced) and it ran. Switched it off and it refused to start again. After a month w/ my local independent, it was traced to a burned-out wire on the back of the fuse panel, post fuel pump fuse. Rewired, ran, stopped. This time it melted the new solder. Finally, (another month) traced to... bad diode in the LH computer which fed current back through the relay, which is why the fuse never blew and the relay was a dead end but caused the resistance which melted the wire.
Hope that was the last of the chase>
Good luck,
Donald

PatrickP

Thanks for all the input. I am picking up a relay tomorrow and will see what that will accomplish. Can't hurt to have a spare in the event that isn't the problem. In the event I need to move on to the cold start valve, can anyone advise as to wher it is an how difficult it is to get to?

Alwin928

I too am an owner of a '85 928 and had a very similar problem approximately two months ago. Not only would mine die warm but since it is only driven on weekends, I had an additional problem with it not always starting after sitting all week. I replaced the fuel pump and relay but that did not solve the problem. The problem was solved when I replaced the LH Jetronic Relay (XXV). I have not had a problem since. I would start with the relays and work my way up to the fuel pump. Good Luck!!

Moss928

For the 85/6 years. The LH Jetronic relay XXV is the same as the Twin-Tune Horns XII relay. You may want to switch them out for testing.

PatrickP

Thanks Alwin & Moss for the tip re the LH Jetronic. Swapped the relays but no go. In fact, horn worked with all relays swapped. Jumped XX and, assuming I made a good connection, no sound from the fuel pump. Looks like, at least at this point, that this is where the problem is. Flat bedding it for a check up in the morning with a 928 mech.

PatrickP

FYI, it was the fuel pump. Happy to be back on the road and VERY pleased that, thanks to this board I was actually able to diagnose the problem. (Wife is also impressed!) Next step on my learnig curve is to do the work! Thanks again, everyone.