1987 3.2 dies then runs ok Help !!

parkers · 05-29-2006, 05:50 AM

when driving along without warning the engine dies completely
its like there is no gas or no spark
don't know which
it will normally start right up and be OK for a day or 2 days or a week then same thing again
anyone had this happen, ?
all help welcome
thanks
Mike

tshih · tshih's Garage

Try replacing the DME relay under the driver seat. That relay often fails over 10 years of use especially if you have had water enter the car. Most wise owners of 3.2 carreras carry a spare relay (about 40-50 bucks) to avoid being stranded when the fuel or spark is cut off by the relay failing. Next check spark plug wires and change fuel filter if that were never done or maintenance was due.

john walker's workshop · 05-29-2006, 06:47 AM

along with the DME relay, be sure that the head temp sensor has been updated to the one with the fat wire and double terminal plug.

parkers · 05-29-2006, 08:36 AM

Thanks
can I get to that without removing the seat ?

Nine9six · Nine9six's Garage

Yes you can.

Jeff · 05-29-2006, 09:10 AM

I'll second the Cylinder Head Temp Sensor.

parkers · 05-29-2006, 09:17 AM

Thanks again
what is this cylinder temp sensor and where is it located (I guess its somewhere on the head )
is this easy to replace ?

dsmeyer · dsmeyer's Garage

Quote:

Originally posted by parkers
Thanks again
what is this cylinder temp sensor and where is it located (I guess its somewhere on the head )
is this easy to replace ?

Third vote for the cylinder head temp sensor and it's not a real easy part to replace.

ZOA NOM · ZOA NOM's Garage

CHT can be reached from the driver's side, under the car. Remove rear wheel, and look for the sensor poking out of the #3 cylinder (closest to driver) head. It should require a slotted deep socket to remove due to the permanently attached lead that comes out of it and goes up to the bracket behind the heater blower motor. I just ground a slot in an old socket for this purpose. Your symptoms seem more likely to be caused by a bad DME relay, however. I would try that first.

Ned nyna 11 · 05-29-2006, 02:17 PM

Um, Ah, if you are trashing the old oh two sensor, chop the wires and use a regular deep or dare I say an adjustable ( metric) to get it out.

ZOA NOM · ZOA NOM's Garage

Um, ah... what does the "oh two" sensor have to do with this thread?

brcorp · brcorp's Garage

The CHT is actually fairly easy, if you have the correct tool. I bought a deep well socket at Harbor Freight and cut a slot in with a dremel.

(I'll post a picture later)

Noney · 06-08-2006, 08:28 AM

Had your exact problem a few years back. Would randomly die while driving or sometimes just buck like a bronco for 3-10 seconds and then either die or run fine. After replacing all the usual culprits (DME relay, CHT sensor, flywheel sensor, plugs/wires, etc.) and still experiencing the problem, I finally gave up and took it to my wrench. He was stumped too, as the problem was very intermittent and difficult to corner. Two weeks later, he finally narrowed it down to the fuel injection harness. Replaced it, and she ran like a scalded dog.

Bonus: all new sensors and relays.....

Good luck.

Rot 911 · 06-08-2006, 08:34 AM

CHT sensor replacement tech article: http://www.pelicanparts.com/techarticles/911_cyl_head_temp_sensor/911_cyl_head_temp_sensor.htm

parkers · 06-08-2006, 02:05 PM

Thanks to everyone who replied
I changed the DME relay Sunday and so far ...... it has been
perfect
in fact it hasnt run this smooth for 12 months
so thanks again
Mike

ZOA NOM · ZOA NOM's Garage

You bought two and put one in the glovebox, right?

lindemans · 06-08-2006, 02:36 PM

If the engine is completely dead at times, it will not be the temp sensor.

I had identical symptoms that disappeared after replacing the DME relais.......good chance you're ok again.

charleskieffner · 06-08-2006, 02:41 PM

when i hear 1987 911! that sure woke me up! quanity (1) new style w/fat wire and double terminal plug cylinder head temp sensor ordered! i aint getting stuck in BFE! well i'll at least try like hell not to! thanks for the TOP TIP! thats whats great about this site....................der stuffen wir nicht ge-thinken about!

rusnak · 06-08-2006, 05:48 PM

I second the "not the temp sensor" sentiment.

It's more likely to be the ignition switch, then the dme relay. I'd start by changing the relay because even if it's not the relay, you'll have to replace that eventually anyway.

ZOA NOM · ZOA NOM's Garage

Rusnak, you realize the problem was fixed by replacing the relay, right?