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:

http://forums.pelicanparts.com/porsche-911-technical-forum/379418-frustrating-959-problem-need-suggestions.html?highlight=959

and

http://forums.pelicanparts.com/porsche-911-technical-forum/379626-still-stumped-959-fuel-injection-problem.html?highlight=959

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

Tease!

Photos!

http://forums.pelicanparts.com/uploa...1196500664.jpg


http://forums.pelicanparts.com/uploa...1196500682.jpg


Different angle:

http://forums.pelicanparts.com/uploa...1196500815.jpg


Here's the one for the Porsche hunk calendar 2008 (JK):

http://forums.pelicanparts.com/uploa...1196500845.jpg

Of course, probably I've embarrassed the heck out of Tony - but he asked for it - he's going to be on the cover of Bruce Anderson's new book!

-Wayne

Also, don't forget the tech session tomorrow, the 959 and that 996 cup car will be there:

That’s a puzzlement to say the least…

It suggests that there are multiple ‘operating points’ for the idle setting and each time the brain is rebooted a new target setting has to be sought out manually. From a control system point of view (open or closed loop) it does not make sense (?) unless we simply compensated for a failing component (closed the widows in a heated building) and/or found an acceptable ‘setting’ that works...

Its amazing to me that with the complexity of this car that pushing one button could clear the idle and mixture settings. You would think that there would be a base line setting which would still allow the thing to run?

But hey..what do I know...I'm still working on paint and body.

Helmethead

I'll make you a sticker...."S3 do not touch"

:cool:

Very cool, and very happt to hear that youe problem is fixed...!

I wish I could be wearing a short sleeve shirt working on my car with the garage door open...its 22F outside right now here in Colorado Springs..

Yasin

Did you write down the mileage? :D

Good cars. Good friends. ...

Anything can be fixed when you get smart heads together!

That would never happen with CIS :)

Wayne - if you could talk Tony into doing one of these for 3.2 Carreras or SCs I'm sure there'd be a lot of interest from this board. Maybe Pelican could co-sponsor.

I'll keep my fingers crossed on it staying corrected. Such a fine looking car.

87 blk coupe

You'd think. But don't forget this is a Euro grey market car with CATs on it - maybe that changes things, or something else has been changed. The car has definitely been messed with, I'm slowly figuring out what's what on it...

-Wayne

Yes, I'm trying to convince them to have one every other month or so, on a different car. Sandwiches & food sponsored by Pelican. Seems like a perfect fit. I'll ask for votes of support on another thread to help convince Tony...

-Wayne

I drove the car home tonight from Callas' shop. Suffice to say, it looks like the problem has been solved! Wow, I will sleep a lot better, as this was *really* bugging me. Be on the look out later on tonight for info on the next project on the car!

-Wayne

Do you own stock in Callas? ;)

Good news. That would have kept me up sleepless for many, many nights, trying to work it out!