JPP

Just a quick update .. I've been taking the car out every day on 'start, shut off, restart' test drives ... just went over 60 out of 60 successful starts under all kinds of circumstances: Immobilizer set, system sets itself, unset system. No failures since I tie-wrapped the clutch microswitch bar closed ...
So, it's looking fairly certain that the switch was indeed the problem. When I had the floor board off and was checking the clutch/switch motion, it appeared that when the clutch was fully depressed, the switch bar was completely closed .. and when the car failed to start, I would press extra hard on the clutch to make sure ... so my conclusion is the switch is funky and needs to be tie-wrapped shut to make good contact.
I should have my can of contact cleaner in hand tomorrow afternoon so my plan this weekend is to remove the switch, clean it as best I can, record the part number if I can find it .. and re-install the switch without a tie-wrap on it .. and do some more testing.

lcorkum

Sounds to me like you are making good progress with this complicated system, it is helpful that we are all learning more at the same time and hopefully will better prepare us of this eventuality. I am expecting that over time we may see this issue also along with the others in this thread.

Good work team!!!
Lloyd

mike cap

Hmm, interesting result. But I said I wasn't very bright.

JPP

^^^Yes, you nailed it in the second post! I revisited the clutch when the car failed after self setting.. Still don't understand all the physical dynamics of the switch failure and may never know exactly what's wrong with it.. But it's been great having the car always start

mike cap

JPP,

Just picking on you my friend. Received your pm. The switch is easy to replace, just a bit of the usual contortions to get in there. I don't have the part number handy - I just got it from the PET.

nine9six

Sounds like you have established that the switch is on its way out...Why not simply replace it and be done with it, instead of all this extra effort?

JB 911

Interesting thread. Since my '96 starts with or without clutch depressed, I am assuming that my switch bar has been tie wrapped shut or possibly the switch just bypassed? I need to have a look to see which I guess, but carrying a jumper along with my spare DME seems like a great idea and gives me something else to try if I ever get stranded roadside.

Now were was that thread that explained how to trick the immobilizer into starting hmmm.... should have bookmarked that one

JPP

Because I'm cursed with the investigative mind of a 10 year old ...

The clutch Microswitch was added for model year '97 and on ... NO SWITCH FOR YOU!

JPP

Yeah ... I thought I felt my chain being tugged It looks easy ... but then again, so did the ignition switch. So ... you just looked at the pet, saw the item 18 for '97 and on and ordered it then? Part showed up ... plug and play?

JB 911

Arghhhh! That settles that then!

Hey, did I tell you I like that mines a '96 yet

mike cap

JPP,

It was easy to change. Picking the right switch out of the PET is confusing. I THINK it is # 993-613-415-00. But please double check this. The PET illustration is not very good.

I checked my records but cannopt find a receipt for the switch.

JPP

I'll probably get groans for this but IMHO, the immobilzer is a fairly decent design. Certainly would stop a smash and drive type of thief ...
So, you have the best of both worlds: Drive Block without the clutch 'safety' switch.

No worries .. in my limited experience, Porsche usually puts part numbers on these things somplace but I'm betting it's the 993-613-416-00 number which rolled from 415 in '97.

pp000830

Interesting. On my 993 there seems to be no switch at all or it is shorted out. Possibly a fix/simplification by a previous owner. Who knows, just one less part to fail and all I have to remember to do is use the clutch or have the car out of gear before staring it, something one must do anyway. I added a similar fix when I tied off the brake pad wear sensors. Like gee I never look at the calipers from time to time, go figure. On the other hand I added a chime circuit when the parking lights, turn signal or headlights are left on and the ignition is off. I guess its to each their own!

JPP

So, today I pulled the switch to clean it up and see if I could verify the part number .... and of course, there is no Porsche part number on it anywhere ... just vendor internal p/n's and stampings. Also, the plunger under the switch bar is sealed with a rubberized cover that's molded into the switch body ... so there will be no spraying of contact cleaner in there. I did order a new switch from Sunset using the 993-613-416-00 for MY '97 and on according to the PET. I sent the part guy some photo's so he could verify it's the correct switch before sending it on to me:

JPP

Also .. another RL'r sent me a couple of links to posts about this switch by our own Steve Weiner .. seems there might be other good reasons why putting our cars in neutral to start them might be a good idea ...

https://rennlist.com/forums/993-foru...ml#post8996067

https://rennlist.com/forums/993-foru...ml#post5800824