[1968 GTO Resto-Mod]

Originally Posted by fbrown540

The key not turning the engine off actually happening fairly frequently back in the day when these cars were fairly new. The cause is generally a feedback loop that keeps powering the ignition. You can test for this by simply unplugging the wire to the alternator. If the engine stops with the key off and by unplugging the alternator wire, you have a feedback loop.

If you have a feedback loop, You could leave the alternator unplugged while you trouble shoot the high idle rpm.

Some causes are:

- lack of a resistor in the GEN light line.
- not properly converting the wiring when swapping from an external to internal regulator. This seemed to happen to many of my friends back in the early 70's.
- improper conversion from a points type distributor to a electronic one. Again this happened to many of my friends.

It been so long that I don't remember what was done to fix the problem, but the fix was very minor in all cases.

I don't know if this applies to your engine, but many GM engines of the 60's had a thin metal plate between the carb gasket and the manifold. Leave the metal plate out and the engine won't idle. I had seen many of my friends leave the metal plate out and couldn't get their engine to run very well.

Maybe someone with more recent experience will chime in.

Originally Posted by PBarkley

Subscribing to this thread...and seeing your recent engine-related post has me on high alert for the same reason with my car, haha.

Glad to see another build staying Pontiac powered!

cheers guys- thanks for your input.
i really appreciate your comments!



the engine is running smooth tonight.
next time i should remember to verify correct throttle cable adjustment before start-up!
today i replaced the spark plugs and it started back up no problem.
still need to troubleshoot key not turning the ignition off.
also, there's a small coolant leak at the top of the water pump gasket and a small power steering fluid leak at the pump high pressure line out.



despite a few interesting unexpected challenges recently i've been making some good progress.
i'm happy to know the machine will run.
thank you for having a look at my project!
danny