Car keeps running after key is shut off.

[Mike]

Originally posted by Z-Priv

had everything you suggested checked and adjusted two weeks ago and it still did it..

2manyZ's you where right it was the ignition switch. Fixed it this afternoon. Thanks for the suggestion..

Can you explain the fix? I don't see it. You replaced the ignition switch and it fixed your dieseling?

Or, was your car continuing to run at full idle speed after you turned off the key?

[2ManyZs]

Glad I could help. Everyone else was giving you the obvious things that cause it, I just thought of the one thing people don't think about until it's the obvious one.

My first Z was a 73 I bought around 81 or 82. It wouldn't run when it when the engine was warm so the girl traded it in. I bought it and tinkered with it for a couple weeks before someone told me to check the water contol valve going to the carbs. I blocked that and it ran great. It also had a ignition switch that I could start the car and then take the key out while it was running. After a while it wouldn't shut off without stalling it in gear, it was shorting out in the switch. Sometimes it ran smoothly, other times it ran rough like it was "dieseling". Since these cars are now 30 years old it is going to be more common since this happpened to me when my car was less than 10.

The greatest thing about this forum is the variety of answers you can get to a question, the answer is bound to be there somewhere.

[My260Rocks]

Yea, im confused how an ignition switch would fix the problem. My car liked to diesel until I dropped its idle abt 250rpm and that was the end of it. If you turn off the key and the thing sputters it should be a predetination(sp?) problem. If it were an ignition problem then the dern thing wouldnt spark OR you'd turn off the key and the dern thing would run until you unpluged your distributor or coil! But hey, these cars to the craziest things.

[2ManyZs]

In my case and evidently in his the switch contact were worn, the barrel of the switch gets worn out, and what happened is it wasn't cutting off the ignition currant. It was as if the key was still in the run position. When you are dealing with cars as old as these weird things are bound to happen, at least they are still simple enough for most anyone to fix, sometimes it just takes a little time to find the cause.