two remaining problems - 1989 S2
 

Hello:

I am a new owner of a 1989 S2 (as of last October) and have been getting it sorted over the Winter. Now that I have it on the road, it's proving to be a lot more fun to drive than I anticipated, and I really enjoy the process of bringing it back to life. I have quite a list of work completed, but am stumbling over two issues
1) Starting issue: When the car is cold, starts and runs beautifully. When the temperature needle is on or above first mark, also starts no problem. When the needle is between cold and first mark, it starts, sounds and feels as though it is on three or fewer pistons, shakes violently will not correct itself. If I shut off the engine and start immediately, it will often start up and run well, other times it needs a bit of a rest. In the course of the "sorting" I replaced the fuel pump, fuel filter, all rubber lines from tank to fuel rail, timing has been adjusted, DME replaced with new. New air filter, two cycles of injector cleaner run through two consecutive tanks of high test fuel. Car has 100,000 miles on it. Any thoughts?
2) Door locks: When using key to open door locks, works like butter. When I try switch in car, I hear the sound of clicking in the doors coupled with a slight vibration of actual door lock stem (?) but no locking. Is it possible the switch is bad even though I hear action in the door? Seems strange the locks work so well with the key.

Thanks

Not really sure on this but might as well try to help: problem 1 makes me think of the DME temperature sensor on the block. However, I only know NA 8v blocks, so I don't exactly know where this sensor is located on the S2.
Should look like this:
https://cimg6.ibsrv.net/gimg/rennlis...8dc68de6f9.jpg

I will try it, Thanks!

My Turbo used to be somewhat like that .. cold start, no problem but when it was hot, just off the track and you turned it off, you could not restart it for a while. It turned out to be bad earths. When hot the connection was not as good as when it was cold. You might find on a lot of threads references to earths on the 944s. The cars are old and the earths can be in poor shape. There's any number of diagrams online to locate allt he earths and maintain them.

The temp sensor on the S2 is at the front of the engine, when you lift the hood and look down, it's right there, just above the water pump. Maybe check the connections.

Door locks, could be a bad switch, but they are pretty solid, could be corrosion of the joints or loose joints as well. It might even be the path from the internal switch goes to an aftermarket alarm system which was popular in the 1980s and 1990s.

thanks for the advice. The alarm issue is interesting, 'cause this car had some wildly elaborate wiring to a vintage alarm. If that's the problem, i won't touch it. Strange that there is a noise in the door when I try to lock with switch, bad alarm wiring would (probably) keep any electrical signal from reaching the lock?

Keith

Some of the old alarm systems had their own central locking control, I had a Python Alarm system removed from my turbo and we found a central locking control and a seperate movement sensor as well as some relays in other parts of the car - distributed so it was harder to find (yep, it sure was)

I was fortunate to have an auto electrician who did his training in the 1980s who knew exactly what was going on and what the original installers would have done.

We also found the remnants of 2 old "mobile phone" car kits .. so much wire!

The door that makes a noise, might have poor electrical connections, or something loose (Like the earth!)

Note: I locked my S2 once with the key on the passenger side, but unlocked it with the key on the driver side - car would not start, had spark but would not start. We swapped all the relays from another car, no joy. I was about to put it back on the trailer when I got the key out of the ignition and locked and unlocked the car a few times on the passenger side .. the last time, I unlocked it. Went back to the ignition and the car turned over immediately and started. Something to do with the inhibitor of the alarm was not releasing on the passenger door when activating the Porsche locking and alarm. I don't know why, several auto electricians have had a look, but it remains a mystery.

I love the car, it is a pleasure to track and drive, but I stay wary of some of the old electrics. Get yourself a set of circuit diagrams, they are on the web. I put mine in a large binder and have used them many times to sort problems - note, the wiring colours are in German (SW is Black for instance - Schwartz)

Question- when you say you “unlock with a key” are both locks opening (activating) or only the lock that you are turning the key in?

The reason I ask is that on 944’s with electric locks, there is plastic push “rod” (looks more like a bone) that the electric unlocking motor uses push open the lock remotely. These break early and often. Because turning the key uses a different mechanism to open the lock, it is possible for electric lock to not work but to mechanically turn a key and open the door.

Let me me know what you think.

Yes, with the key, both locks (both doors) were engaging and the little black post with the red LED on it was going down on both doors, central locking was engaged.

I know the whiteish dogbone you mean. I have had to replace a broken linkage on this car and discovered part of the handle casting was broken. Had a look around and found a lot of people recommended going to a 968 door handle where Porsche had solved the problem created in the 944 door handle. It put some stress on the axle of the mechanism that controlled the linkage in the door, the 968 handle does it way better. (I have only installed the LH door handle, and have not got to the RH handle yet) 968 door handle kit came from Lindsay Racing.

I did find, that removing the window was by far the easiest way to install and remove the door handles, and allows very good adjustment access - I tried the other way, and it was frustrating beyond belief. The first time I did it though I learned to have the window up (!) and also I scratched the tinting and had to have that window redone.

The incident I describe above was before I installed the new handle. I have never been able to replicate the condition, but everyone seems to agree it is something to do with the alarm(s) and is some kind of inhibitor. The starter motor turned over, lots of spin, had spark and fuel, just would not start.

I am wondering now, on reflection, if you are onto something there, that perhaps the door unlocked (both doors) but the alarm wasn't fully turned off due to the position of the white dogbone on that door .. will have to have a look at that, thanks.

So the key opening the locks is not electrically activated, but the interior switch is? I can use the key, and it is so smooth I assumed it is electric. But the switch makes a noise in the door, but no action. That must be the broken dogbone. This car had a phone, and an after market alarm that created a Gordian Knot of wiring.

The flashing light on the door lock stalk flashes 24/7 - driving, parked, engine on or off, doors locked or not.....

Exactly! The key turns one pushrod from tumbler to the door latch mechanism, and the electric button actives a small motor that pushes a different push rod (the white plastic one). The plastic one is cheap and fairly straightforward to replace. Good news is if you hear the clicking when you push the button, you mostly likely only need the plastic dog bone.

So here is how your power locks should work:

Inserting a key should lock and unlock both doors. If they are not, check BOTH white dog ones. If that is not the problem there is a tiny microswith on the actual latch mechanism that may be broken off and dangling. Check this if replacing dog bones don’t fix your problem. Don't bother checking these until AFTER you have replaced the dog Bones ($8.95 each at 94online) and established that is not the problem. Why?

...removing the door latch has caused strong men to use strong language...

Inside the car, on either door, when you push down on the plunger it only locks the door you push it down on. BUT- when you pull up (unlock) if will unlock both doors. Weird...

Finally, pushing the switch on the dash will cycle the locks. Both up when down and vice versa.

If you need more advice PM me and we can take it off line.

Also, with the key out of the ignition, the switch on dash will only lock the doors and not unlock then. Pulling up on the plunger will only unlock both doors, but not re-lock them. More delightful West Gerrman weirdness.