Ignition lock won't turn to start

[walt83sc]

I just resolved an issue with my ignition lock on my 1983 SC and though I'd share. I started having trouble with the ignition switch where it would turn to "run" but wouldn't turn further to "start". It initially corrected itself after trying a few times (and turning the key over, but that wasn't what fixed it). It finally got so bad, I gave up and removed the ignition lock.

It didn't appear to be user-serviceable, so I shopped around for a while, and finally ordered one from an Amazon reseller. (Fortunately?) They canceled the order the next day, said they didn't have it and presumably didn't feel like trying to get it.

So, it sat for a couple weeks, while I was out of town and basically ignoring it. Then I got bored while watching a training video, and started fiddling with the lock again and noticed something I hadn't seen before: a retaining pin that was ever so slightly loose and stick out. I grabbed a pair of side-cutters and gently removed it. Detail shown in red circle:



It was... The Holy Grail... Then the fun began.

The lock cylinder itself came out, and I found that there was a locking pin that's designed to prevent re-engagement of the starter once the key has been turned to start, then back to the run position.




That pin was supposed to be retained by a small shim/washer/retaining disk that wasn't turning correctly. Also notice how large the gap is in there; there really isn't supposed to be any. That's really the heart of the issue; the switch is worn and loose.



I put it face-down in the vice jaws, with the black keyhole cover sticking out so it wouldn't get bent, and gently tapped it with a very small ball-peen hammer. Meh, still loose.

So I got a center-punch, set it face-down on a rag on the anvil, and tightened up a couple of rivets on the back that seemed to be suspect. A little better. Then I gave the rivets a few more good whacks with the peen-end of the hammer again, and it's *much* better now. Sorry I forgot to take pictures of the rear before I reassembled the whole thing, as I can't seem to get it back apart now, and don't really want to break it.

Whoohoo... I just saved $460. BTW, the lock assembly is a Standard Motor Products p/n US-664. If you search on a Porsche ignition lock, it's significantly higher. Unfortunately, it has to be purchased with the electrical switch portion as well, as an entire assembly, so whether or not your electrical switch is still good, you have to replace it. Of course, you can buy the electrical portion by itself if you need to, for $115 or so here at Pelican.

One last bit. It seems that forcefully pulling out on the key while turning it from "run" to "off" helps re-engage that retaining disk, so if you get in a jam, try that. Then when (if) you get home, take it apart and whack it.

Hope this helps someone else. And if anyone knows whether the lock cylinder itself can be replaced, I'd appreciate the info. It's bound to happen again, maybe somewhat sooner than 30 years from now...

[tazzieman]

Originally Posted by walt83sc

I just saved $460. .

Well done! Yes , lots of things can be rescued with a bit of analysis , patience and basic know how. Every $ saved can be justifiably pointed at the next upgrade

[86 911 Targa]

Now pour yourself a few Crownies................

[Oldmother]

Great write up, thanks! My ignition lock has been doing this intermittently for the past few years, and I have just been dealing with it. Will fix it with your method this fall.

[spuggy]

Interesting write up Walt!

Originally Posted by walt83sc

The lock cylinder itself came out, and I found that there was a locking pin that's designed to prevent re-engagement of the starter once the key has been turned to start, then back to the run position.

It's different on my '77. There, if you remove the electrical portion, the key will do anything you like (I've also got an earlier lock - chrome on it - that behaves the same way).

Trying to debug another problem, I borrowed and fitted an '86 930 electrical part - THAT had something internal that prevented you going from run to start if you'd already hit start without turning it all the way off - with a screwdriver and just the electrical bit, it's pretty clear

I re-fitted my original electrical doo-dad, back to normal. Both the earlier electrical bits behave the same way as each other.

So it looks like they did it in the lock itself - for the SC - but not later....

[tirwin]

This is a great write-up! I replaced my assembly last year. When I took mine apart, the tumbler wasn't "catching". I could feel whether it would work or not just by how the key turned. Figured it was a lost cause and swapped it. Had Tony Eugano refurb the rest of my cylinders and re-key to the same key. This might've saved me some cash!