jim_l

Ok heres my sad story, stranded in NJ 150 miles frome home. seemed to be
a hot start issue, ran down the highway fine stopped to make a phone call cannot restart the car. local mechanic thinks flywheel sensor "no spark, no gas" but will have to order. I Have the car towed home and today car starts and runs fine. i would not think this type of sensor would be intermittent? any other ideas.
thanks as always .

Ag02M5

Check the connector in the engine bay for the speed sensor. Mine had disintegrated. May be you are getting an intermittent connection?

FYI...mine is on the left side (looking at it) not too far from the fuel filter but not touching the body of the car (for my turbo). 2 prong connector IIRC.

Good luck.

DAVISRILEY

Dme relay perhaps?

Metal Guru

Resistance values for the reference/speed sensor (from the nearly useless Bentley manual);
pins 1-2 960 ohm
pins 1-3 over 100,000 ohm
pins 2-3 over 100,000 ohm

I measured only 530 ohm on 1-2 (my car isn't running either).
Comments?

mlucitt

Porsche sourced a plastic part that does not hold up well in the engine bay environment. Mine fell apart the first time I tried to disconnect it.

GM makes a very nice 3-conductor weather-proof connector with crimp-on terminals. Here is the link:
http://cgi.ebay.com/ebaymotors/Weath...spagenameZWD1V

It took me about half an hour to replace the crumbling connector.

Mark

Colin 90 C2

has the Dme been out lately?
Was the car cranking with no start?

Ag02M5

Linkie no workie.

jim_l

Yes engine cranking good, no start spent the night in a hotel still would not start the next day. shop told me no spark and no gas, dragged it home on a flat bed 3 days later start and runs, fine. I would like to see the gm connector but the link is gone. and i cant seem to find that flywheel sensor connector in my car. it seems you access the sensor from under the right rear wheel area. have to dig a little deeper i guess

Rocket Rob

The connector for the flywheel sensor is on the left-hand side of the car. If you remove the heater booster blower, you will see it. Its a round connector about 1/2" in diameter and approx 2" long. The sensor is next to the flywheel and its wire routes through the engine tin into the engine compartment itself.

Edit: You may want to read through this thread. It discussed diagnosing the flywheel sensor in detail. https://rennlist.com/forums/showthre...ensor+flywheel

KirkF

I would bet its the dme relay before the flywheel sensor, but there has been a couple of posts on here about the sensor failing over the years.

Put a scope on the leads and check if you have a square wave when you crank it over.

See attached pictures.

Kirk

KirkF

I should add the plug seen above is the DME connector located under the drivers side seat.


Kirk

Colin 90 C2

as said earlier, check the connector. Behind the blower motor.
remove the air ducts and the blower is held in by 3 10mm bolts.
Once removed, you will see the connectors.

jim_l

ok, so i do have a new dme relay from pelican, removed the old one and popped its cover. top coil was a little discolored "darker" and had a smell burnt electronics, contacts look fine. found the 3 pin connector it under knock sensor 1 it seems thanks colin, i will scope the output before i replace it. hope its just the relay. thanks again everyone for all the input

KirkF

I have had dme relays fail, and they would start working again when rapped with a wrench. They are truly a POS.