More progress on the 959...
 

A brief update: Last night I spent about 5 hours reading the factory workshop manuals to try to figure out how to build a diagnostic code reader for this car. Then this morning, I got the information emailed to me (violin959 - thanks Bryan!). Tony Callas from Callas Rennsport also offered to help me with the box too. I was very close in my "guesses", but I had made a few mistakes that might have damaged one or more of the computers if I had tried to plug the box in. With the new information in hand, I modified the box I wired last night, and successfully read and cleared the Motronic trouble codes.

Unfortunately, one of the codes was "Motronic unit damaged - replace unit". Well, we'll just ignore that one for now, and hope it doesn't come back.

The trouble lamp is still on, on the dashboard, I'm assuming that's related to the trouble codes in the drive-control system. The procedure for clearing those faults seems somewhat complicated, and I will probably have time to do that tomorrow (before I take my kids to Disneyland!).

Anyways, having a functioning box is of paramount importance - you can't really work on these cars and figure them out without it. I did drive the car today, and there was indeed something wrong with the first-stage turbo. I'm not an uber-expert on turbos, to the point where I can figure out what is wrong just by listening, but my first guess was that it sounded like the wastegate was stuck open. Boost pressure was only at .5 bar absolute, which is lower than atmostpheric pressure. Didn't seem right to me, and the car at lower RPMs had no real power. The upper end is still very strong, but the lower ranges are sluggish, to put it mildy. I'm looking forward to working on this, I need to remove the rear bumper to access all of the exhaust and turbo machinery - I suspect that will make a really, really neat photo when that's off. Also, I need to hook up a boost pressure gauge to test the total boost (gauge in the dash isn't accurate enough, supposedly, from the factory manuals). The factory test procedure actually calls for you to drive around on a flat surface and floor it while braking at the same time. Odd, but I guess a rolling dyno is out of the question since this is a 4WD vehicle.

I wanted to button up the driver's side door today, but I found that the electronic door lock microswitch was broken, so I had to order a new one for delivery tomorrow morning. Hopefully, I'll get this installed and working, and then I can button up the driver's side door and not worry about it again for a long, long time. After that, if I have a few moments, I'll put the new hood crest on the car (The one I have is made in Germany).


Here's one of the plugs under the seat that accepts the diagnostic box. It's a six-pin connector that's similar to the one used for the power seat harness.

http://forums.pelicanparts.com/uploa...1192690632.jpg

Here's a photo of my box plugged in and working. Today I read and reset the codes for the first time...

http://forums.pelicanparts.com/uploa...1192690651.jpg

Closeup of the microswitch that is broken. New ones are $75 in the Pelican catalog...

http://forums.pelicanparts.com/uploa...1192690662.jpg

Here's where the microswitch goes, it wraps around the door handle:

http://forums.pelicanparts.com/uploa...1192690671.jpg


Here's the door handle and microswitch that broke:

http://forums.pelicanparts.com/uploa...1192690678.jpg

Here's a photo of the passenger side window switch hooked up. It didn't work when I first put it back together. I then started checking fuses, before I remembered that power is routed through the driver's side switch, so if that switch is broken or disconnected, then the passenger side window won't work.

http://forums.pelicanparts.com/uploa...1192690757.jpg

Here's what the driver's side window switch looked like. If you're going to have the wires hanging like this, it's a good idea to pull the fuse for the window motors so that you don't accidentally ground a live lead.

http://forums.pelicanparts.com/uploa...1192690749.jpg

Also a bit of good news, the Air Conditioner randomly started working today. I think maybe some temp sensors need to be replaced, or something like that. It would also help if I read the manual on how to use it - it's unique to the 959, and not completely obvious...

-Wayne

Remove it, you won't need it - Hey, think of the weight savings!

Heating and cooling not being completely obvious in a Porsche? Surely you jest.:D

Only 911s (& old beetles) have 3 completely independent systems:

1. Fresh air
2. Heating
3. Air Conditioning

Find any silver paint?:)

Not trying to be a smartazz - just wondering if the conjecture has been put to rest.

Is it just me or does anyone else find it charming that even on a showcase item like a 959, Porsche continued to engineer in a bit of quirkiness to befuddle HVAC-spoiled Americans (What, a single unit that combines heat, A/C and fresh air? Wie dumm!). ;)

Brian

"New ones are $75 in the Pelican catalog..."



--call up and ask for Scott, he gives buds with cool cars a 60% discount and doesn't tell the boss about it... He figures it fosters return business...

;)

Hey now http://forums.pelicanparts.com/support/smileys/wat5.gif

Wayne in case it hasn't already been said, thanks for sharing all this with us. The pictures and descriptions are awesome.

Keep up the good work.

Sorry Scott, target of opportunity....

Responding with that quote made me chuckle, and since I remembered your name 1st from treating me well in the past, well, you got lucky and got chosen...


http://forums.pelicanparts.com/smileys/smileys1.htm




(why aren't smilies working for me lately ??? That's supposed to be the little guy holding up a beer glass...)

Yes, it was detailed in this thread:

http://forums.pelicanparts.com/porsche-911-technical-forum/371288-959-ppi-update-re-color-change.html

The car was originally black-metallic and was repainted black. The silver car featured in the Road and Track article was another car that they imported at the same time. That is the car that some people have seen in the Newport Beach area from time to time (the guy uses it as a daily driver).

-Wayne

[QUOTE=

Unfortunately, one of the codes was "Motronic unit damaged - replace unit". Well, we'll just ignore that one for now, and hope it doesn't come back.[/QUOTE]


This sounds like it could be an expensive one on your list of fixes!

Good Luck with that. Love the documentaion of fixing up an abused 959.

Kinda funny to see that even Wayne diagnoses stuff like us average doods- the wish for it to be a "glitch." :D

Ask around your local area and I bet you'll find one. The Audi and Diamond Star turbo gurus have to have one to dyno their cars.

GT Pro in Fullerton has a 4WD Dynojet 424X http://www.gtpro.com/index.cfm/ that you could use. You could set the dyno to hold a load at a specific rpm and it should keep you there - they use big locomotive brakes to load the drums. They've dyno'd Boxters, Caymans, 993TTs, 996TTs and n/a, 997 TTs and n/a and have all their run files stored in the computer. It would be interesting to overlay your power curves over some of them.

So how does the diagnostic code reader work? Does it blink in morse code? ;)

I've got one word for you guys "spell check"

Where's my smiley guy?

turbo systems are fairly simple, i'm sure it's a little more complicated than what i used to mess around with though on the control side.
the wastegate is controlled by a vacuum, if it's multi stage then there is most likely going to be a couple vacuum switches, one for each stage with it's pre-determined boost level.
i had a setup in my glh-t which was 3 stage and was controled via micro switches on the shifter, i controlled the set boost for the 3 stages with 3 grainger valves/switches (a ball bearing/spring valve).......
i can't see the 959 being too far off of this basic principle, but most likely uses a main control box, being vacuum switches are mechanical it may be as simple as that but all hidden away in a module.

did you check the board on the dme for any bad soldered connections?

959 sequential turbicharging
 

I found this understandable (?) explanation in my 959 'Sales' Brochure (only have the pamphlet -never picked-up the p-car)


http://forums.pelicanparts.com/uploa...1192756393.jpg

Wayne its nice to see that the 959 uses the same microswitch as the 911s of its time period.

BTW, did you just slide it off away from the handle? I tried prying mine from the side, and I thought I was going to break it in two.

Thanks again for sharing,
Matt