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Wayne 962 Wayne 962 is offline
Author of "101 Projects"
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Tricky 959 Problem Resolved by Callas today - (was Wayne's messup?)

Okay, so I took the car over to Tony Callas' shop yesterday for a photo shoot. Randy Leffingwell was shooting a bunch of cars on lifts there for the cover for Bruce Anderson's 3rd edition of the 911 Performance Handbook, and the guys wanted the edge of the 959 in the shot. Very cool. Tony, Randy, and Bruce are all very cool dudes.

So, while we're waiting "for the light to be right", Grant and I took a closer look at the car. Grant is formerly from Andial and used to work on the 959s (and did the prepurchase inspection with Tony too). Well, I explained everything that I did, and he mentioned that I may be barking up the wrong tree with repspect to where the problem lied. Since the problem started so suddenly, I assumed that it was related to a component failure.

For those not familiar with the problem at hand, here are the two previous threads:

Frustrating 959 Problem -> Need suggestions...


Still stumped - 959 Fuel Injection problem...

Well, we started looking at the basics, and took out the manual to set the mixture and idle speed according to the factory procedure. I tell you, those Germans don't really know how to translate too well, as it didn't quite work the first time because we read the book literally, instead of what made sense. After setting the idle speed / mixture, we then set the mixture for the loaded range using a procedure that violin959 emailed me a few weeks ago. This procedure is not in the factory manuals (seems like an important omission to me).

Then we got interrupted and had to move the car to shoot the photos. I then had to leave to take my daughter to MyGym (because my wife was having eye surgery), so I left the car with Callas' crew. Well, they worked on it a bit more after I left - checking the mixture again using their CO machine (mine at my shop is no longer working ). Conclusion - after readjusting everything, the car appears to be starting and running fine. It was raining today, and I was in a hurry again, so we didn't get a chance to drive / test it, and I left it at Tony's shop so that it will be there for tomorrow's Tech Session (12 noon for those of you who are interested in 1990s and later 911s). But, the good news is that it started up perfectly cold, and idled fine, which is what it hasn't done since I came back from Florida (Rennsport).

What happened to it? I think I made a mistake using the handheld computer. Here's the deal - to put the car in diagnostic mode, you switch on the ignition while holding down button 'S2' on the box. However, if you hold down button 'S3' - well, that resets the flash (apparently), and clears out all of the idle and mixture settings and resets it back to a default level. When we tested the car, it was running very lean at idle, and rich in the loaded range. I think that when I was showing the code reader to someone, I accidentally pressed down the 'S3' button when turning on the car instead of the 'S2' button. Seems like you'd think they wouldn't design a system that can be cleared out / reset by such an easy mistake, but indeed I have seen things like this many times before.

So, tomorrow when I go pick up the car from Callas Rennsport, I will be able to tell for sure if the resetting of the mixture has fixed the problem. This is the problem that caused a bunch of other problems when the car stalled at Willow two weeks ago.

Wayne R. Dempsey, Founder, Pelican Parts Inc., and Author of:
101 Projects for Your BMW 3-Series 101 Projects for Your Porsche 911 How to Rebuild & Modify Porsche 911 Engines 101 Projects for Your Porsche Boxster & Cayman 101 Projects for Your Porsche 996 / 997 SPEED READ: Porsche 911 (October 2018)

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Old 11-30-2007, 11:17 PM
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