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I started having problems with a 968 in the hot days of August. The engine would shut off on hot and humid days even when the coolar temp was normal. Sometimes this would happen even when the car had not been running, just sitting in the hot sun. When the sun went down, it re-started fine. I replaced the relay and computer for the cooling fans which seemed to cure the problem. However, last week, on a warm but not particularly hot and humid day, it just died and will not re-start. The nearest dealer with a computer is 80 mi. away so I am looking for some solutions to try before towing it in. Thanks.
Answer -
Hi Don. I would be hesitant to tow it 80 miles too.
One thing that causes the symptoms you've described is a faulty air flow meter. The "meter" is really nothing more than a swinging door...the position of the door is a reflection of how much air is rushing into the intake manifold...and the car's computer responds to that measure by matching the airflow with the right amount of fuel. When the door has built-up gunk and crud surrounding it, it will get balky and will not move smoothly into its proper position, thus sending an erroneous measure to the computer. Heat will cause all kinds of grief in terms of expanding metal surfaces and how gunk will react.
If the computer thinks more or less air is moving and can't accurately send the right amount of fuel as a result you could easily have the equivalent of the old fashioned flooded carburetor...or vice versa.
The air flow meter is known by many different names...and I can't check my normal references for the 968 to give you the best name.
By the way...once the dealer's mechanics have dug in deep enough to get the air flow meter in a position to evaluate the gunk level...they'll replace it...not a trivial expense.
Dave
OK, with your help and that of a friend who sent my a picture of it, I found the air flow meter and have removed it (Actually it was part of the assembly I had to get out to replace the fan sensors). You are correct in snticipsting that it is covered in gook. But where is the "door" you refer to? Is it the black apparently plastic plate on the bottom (as installed in the car) that says "Bosch"? Thanks.
AnswerFollow-up 9-23
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Hi Don. Yikes you're quick. I've only got a picture as well, but the Bosch plastic piece should be the "door". I'm referring to my Haynes manual: Porsche 944 1983 thru 1989 Automotive Repair Manual (their book # 1027. If you can get your hands on a copy, the text and pictures covering the "air flow sensor" are particularly good...especially in testing its action electrically...while you're there. If you don't have access to one...I can fax you 3-4 of the key pages and you'll see what I mean. If you'd like me to do that send me a fax #...send it to my e-mail: daves356@yahoo.com.
Dave
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