Motor not stopping on ignition off
 

My '87 3.2 911 sometimes runs on after the ignition is turned off.

It has about 120K miles on it and uses absolutlely no oil.

I'm about to carry out a standard service (plugs, valve clearances etc) for the first time (my first time not the car's!) and am wondering if there is anything else I should check?

Puttt, puttt, run on or full engine running with all the gauges and lights dead?

phut, burp, fart etc. Never for more than 2-3 seconds but that feels like an age when your pride and joy sounds like S**t. Lights etc are shut down by the ignition off.

That's dieseling....could be timing or fuel mixture or a leak in the exhaust.

more info needed
 

When you say it stays running with ignition off:

1. does it chug along for a few seconds and then die? If so, it is dieseling.

2. does it keep running as if the ignition is on? In that case, your talking about a problem in the ignition switch, which I have had.

could be dme relay under your seat - check it...

/Jack

Chugs along for a few seconds - So sounds like dieseling. Hmm - what do I do?. fueling was recently checked and okay. What else can cause this?

timing and octance on gas?
 

Some immediate things to check. Do you have a timing gun to check the ignition timing. All the standard books and this forum have instructions on how to do this.

Alson, try using a higher octane gas