Help. Stuck in CA with 964 C4 stalling in the Rain

So I need your help guys. I'm stuck in a bind. I purchased a 1990 964 C4 with 115K on it from Arizona. There has been 3K miles on the rebuilt engine by Motor Meister. The total cost of the rebuild was $6K. The car runs great. Very stong and solid.

The warning light goes on at 70mph. The previous owner took it to Porsche and they told him it was the Vertial and Horizontal accel sensors. I have the print out from the diagnostic. They need to be replaced but the car is still drivable. (According to the dealership)

I was hoping to drive it back to seattle to have them replace it there.

I made it as far as San Francisco until it started raining. About an hour into the heavy rain the car suddenly lost power and stalled. I can immediately restart the car and it will idle and run just fine for about 30seconds to a minute. Then the same thing will happen. If I tap on the gas it will immediately stall.

After a 10 minute wait and 6 attemps I restarted the car and it idle for several minutes. I was then able to drive back to a friends house in Los Altos.

Unfortunately I need to make it back to Seattle by Monday. Any ideas on what it could be?

I just tried to start the car again but it idles roughly at about 500rpm.

Eventually the idling normalizes to 820rpm but after some driving the car idles rough and stalls.

I also own a '88 911 3.2 and I've never seen anything like this before.

Fuel filter? Fuel pump? Ignition coil? DME relay? Unfortunately the dealship is close until Monday.

Any advise or wisdom would be very much appreciated.

Thanks.

Carlo

I don't know if this will help, but my 77 had the same symptoms, i got caught on the way home from work one day, I replaced the distributor cap and rotor, this worked, it has happened again. I'm not sure if this is it but try to dry out the cap, or spray wd-40 on it and see what happens????

Good luck, and let us know the results.

Shawn

Unless it is just a coincidence, I'd say water (as in rain) equals some sort of wet ignition component. Spray WD-40 or CRC on every ignition part you can find in the engine compartment. A new cap and wires would be nice, but you won't find them at the 7-11 on a Sunday! I hope this works, but I know next to nothing about these new fangled Porsches.



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Doug
'81 SC Coupe
Canada West Region PCA

Carlo,

It certainly sounds like a simple case of water into the distributor cap area! Dry off the underside of both caps, and see if you can find a tube of silicone grease tomorrow at a parts store such as NAPA. Pull all of the wires out of both caps, one at a time! Dry and wipe out each receptacle, and the wire end, then put silicone grease into the receptacle and on the wire end ... plenty of grease! Do the same at the wire terminal of the two coils. Also, run a bead of grease around the base of each cap.

The car SHOULD now run as before and be safe from further rain showers. If it does not run correctly, I suggest a dealer or independent shop on monday. Good luck!
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Warren Hall
1973 911S Targa

[This message has been edited by Early_S_Man (edited 03-03-2001).]

Try drying and WD 40 tricks. If your in the dry and it is still F...ed up. Check the gas for H 2 0. Drain the tank and replace the filters. Also check the fuel pump. The H 2 0 can be a real bugaboo. Good luck.

I had a wierd one with a 650 Yamaha. I trailered it on an open trailer through heavy rain for an hour and a half. Gas tank was filled before the rain and closed tightly. I left the trailer and car at my cabin and tried to ride the bike. Lost power cut out restarted, little power. The solution was to drain the carb float bowls every now and then and ad gas to the tank.
6 drains or so in the 200 mile trip had it running fine.

Dan

Sorry double post......Dan

[This message has been edited by diverdan (edited 03-04-2001).]

Wow! Thanks for all the replies guys. Unfortunately the distributer drying didn't solve the problem. I ended up dropping the car of at a Porsche dealership and flying bacy to Seattle. I have a business trip back in SF this week so hopefully I can pick up the car then. I'll let you guys know what the dealer found.

Thanks again for all the advise.

YOU DRIVE YOUR CAR IN THE RAIN?
JMPRO

Hell, you should see us in the Midwest, driving around in rain, sleet, and snow. 911s are great in the weather. Just don't lift on a corner Trust me!

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Mark Szabo
1986 911 Targa 3.2
1987 Escort 5-speed 1.9
The Porsche Owners Gallery

I'm gonna take a guess and say fuel pump or filter. What do I get if I'm right?

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Tyson Schmidt
72 911 Cabriolet

If your right you get a $1k bill from Porsche.

The dealship is suppose to call back this morning to give their diagnosis. They charged $127 just to look at the car. Ughh... I can't wait to see what they find. I suspect it's the fuel pump or fuel filter as well. I doubt its any of the major systems because there were no warning lights on the dash.

I'll send an update when I get the news.

-Carlo

So here's the latest. The dealship claims that the O2 sensor is bad and the fuel mixture needs to be adjusted. I thought they couldn't be adjusted on the DME cars. Hmm.. I have never known a bad O2 sensor to cause a car to stall.

This is a very reputable dealship and I've taken all my VW's, Porsche's, and Audi's there. They have never misled me in the past. The car is suppose to be completed this afternoon.

So here's the latest. The dealship claims that the O2 sensor is bad and the fuel mixture needs to be adjusted. I thought they couldn't be adjusted on the DME cars. Hmm.. I have never known a bad O2 sensor to cause a car to stall.

This is a very reputable dealship and I've taken all my VW's, Porsche's, and Audi's there. They have never misled me in the past. The car is suppose to be completed this afternoon.

Yo believe that? Your driving in the rain, car dies and its an oxygen sensor and a fuel mixture adjustment? I don't think so, unless the adjustment is to to reduce the amount of water in the petrol. Dang, you could throw away the oxygen sensor and it should still run fine, maybe a tad rich, but you probably wouldn't not know the difference. Just from my humble limited experience, but I'd be willing to learn something as long as they don't clean out my wallet in the process.

Good luck and keep clear of smoke.

Dan

Well the car's back from the dealership. It's still raining and the car runs like a champ. No stalling. Still confused as to the connection between stalling and the O2 sesor. Maybe the dealership did something and didn't tell me. Not likely though. This is why I don't take my cars to the dealership unless I really have to.

Just in case you wanted to know. I was charged $250 for the O2 sensor and $275 labor. $525 total for a $75 part and 30 minutes labor. Other than the mixture adjustment it was a pretty trivial job. Of course I would have thought about checking the O2 sensor.

At least the car is functional and I can drive it back to my mechanic to look everything over.

Many thanks "Pelican Support Group Anonymous" for all your help and advise.

Cheers.
Carlo

Was there any water down under the drivers seat?

Nope. The inside was bone dry. The engine compartment was relatively dry. Both ditributer caps were dry as well.

I suspect that the rain and the stalling might have been coincidental. That night when it happened I let the car drive off in the car port and it did the same thing after warming up. I don't suppose you've had this happen to your 3.6?

-Carlo

I'll knock on wood, but I haven't had any problems at all with the 3.6. I have the 02 sensor in a test pipe.

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Jack Olsen
1973 911 T (3.6) sunroof coupe
jackolsen@mediaone.net

Congrats on getting it back on the road. This modern high tech stuff makes it tuff on us DIY types....and the wallet. Guess it save on gas, engine wear, and the environment. I wonder what the financial penalty is in the long run. I may never get to know because I think that my mid eighties turbos are as far as I'm going to take it. From here on in I'm looking for older stuff.

Dan