Won't idle w/o choke - sudden change in function
 

1983 with manual and carbureted 12a

I just finished changing my clutch. Other than pulling the transmission, the air cleaner and the clutch slave cylinder, I don't think I touched anything up top....intentionally anyway.

The clutch is in, the car starts, but after the choke drops out, the engine immediately dies if it is at idle. You can restart it with choke and it runs with throttle held above 2000 rpm. This has been confirmed twice now. Once last night and once this PM. Both starting from cold. Runs OK until the choke drops, then nothing.

Tried with the cleaner removed and the idle compensator plugged per the shop manual instructions on idle speed adjust. No change. It is not the choke butterfly, it runs fine when that is nearly open as it warms.

Since this is a sudden change, it worked fine before and doesn't work after the clutch job, I assume something got bumped or disturbed but I can't find anything that looks out of place.

Suggestions appreciated.


Thanks,

Zane

Check everything that is emissions and vacuum related, also the ground wire fron the firewall to the engine. You may have broken a plastic piece in the rats nest, does sound like a vacuum leak.

One hose from the air cleaner goes towards the rear of the intake. If this has come off the intake, it will act as you describe.

Found it!
 

There was on large hose that was not connected at the bottom end. Found it when I was checking for leaks in the line from the cat. Plugged it in and all is well, idling smooth and slow.

Thanks for your suggestions, and those in the "frustrated" thread.

Zane

I bet it was the hose I was refering to. Between removing the air cleaner, and the location near the rear of the intake, it's very easy for the hose to become disconnected, especially when pulling the trans.