Engine died while driving- 85 Carrera ???

csmab · 07:21 PM

I just got my car back from a major 60k service last week. Car was running like a champ. I was driving today and the car left me stranded. Cruising at 80mph in 5th gear and I notice some loss in power right as I was decelerating for a stop light. When I came to a stop I noticed an erratic idle. Car was revving from 900 RPM to 2000 RPM, back to 900 back to 2000. Did this about six times and died. The car would not start back up. Starter was cranking the engine but it just wouldn't start. My first thought was the DME relay. I had one with me that I bought from our sponsor. I switched it out but it still wouldn't start. I noticed the original relay said 15 amp but the new one said 30 amp. If it was a bad relay would the 30 amp work fine in place of a 15 amp? I am guessing it isn't the relay. Any thoughts? 1985 turbo body with 62.4k miles.

Thanks,
Craig

JeremyD · JeremyD's Garage

First change out the DME relay.

if that doesn't fix it - pull your connector to your cylinder head temp sensor - if it's a one wire = then I'd replace that.

csmab · 03-27-2010, 07:34 PM

Unfortunately I did replace the DME relay with no success. I will check the cylinder head temp sensor.

Craig

steely · 03-27-2010, 08:19 PM

Craig - while yer looking at that, check your speed&reference sensor cables too - if the insulation is cracking off in small chunks, they could be showing their age. If one opens up, it could cause a shutdown. Maybe the major maintenance job dislodged them and they gave up.

The other primary stuff is fuel, air and spark.

Quicksilver · 03-28-2010, 06:11 AM

A common "Gee it just died" is the fuel pump. The pump doesn't run until the DME sees that the engine is turning over so testing it is more then just turning the key to 'On' and listening.

Disconnect the DME relay and jumper the fuel pump connectors to see if you can hear it running under the front. (The pump is located under the middle front right behind the steering rack and is covered by the same splash pan as the rack.) The DME relay is actually 2 relays in one box so there are a number of connections on it. The connection you want to make is from #30 to #87b. Just connect it long enough to listen for the pump.

chateau · chateau's Garage

To test the relay, feel the relay when you switch to ON "not crank"' you should feel a click, the switch to crank and you should feel another click. If this does not happen then the relay is not working. Have you checked the fuse? Mine died and it was when I checked the Ohms on the speed and flywheel sensors that I found the problem. Mine ran without the CHT sensor connected, so that should not make it stop, just not run correctly.

csmab · 03-28-2010, 11:33 AM

I love this site. For those who were guessing cylinder head temp. sensor - you were spot on. The connection was actually loose on the left side of the engine. Snapped it back into place and it fired right up. Wish I had known this prior to waiting 90 minutes on the side of the road for a tow. As one person indicated it probably got bumped during the 60K service last week. Thanks everyone.

Craig