high idle when warm

[66thunder]

On a 1969 351, i'm experiencing a high idle after car is warm and running.  I notice it when i come to a stop, if i tap the gas, it does drop down to normal.  The hot air choke is disconnected, and carb plates are wired all the way open.  Sound like something in the carb, or still choke related?   

[Mongo]

i had that same problem with my 69 gt350 and found it was the throttle cable. i disconnected it from the carb and sprayed wd40 both when cable was extended and close. if figured to was rust or dirt,  be careful the plastic part of the cover shield over the cable is brittle and if you bend to much up and down, it might break.  keep us posted.

[1967 eight barrel]

CRC-56 is a better choice.

[Don Johnston]

CRC-56 is a better choice.

Yes it is.

[richflorence]

Good info, Mongo. Mine is doing the same thing.

[rhjanes]

Powdered Graphite.  Find it in the Locks aisle of the big box hardware stores.   Also great for choke cables, which can be taken apart, cleaned with brake cleaner and then use the graphite to lube it.

[Don Johnston]

Choose wisely to continually use either a wet lube or a dry graphite.  Do not alternate.

[1967 eight barrel]

If that doesn't help you might see if your power booster has a vacuum leak internally.

                                                                                             -Keith

[rhjanes]

Choose wisely to continually use either a wet lube or a dry graphite.  Do not alternate.

Very true!  Clean the cable, take apart.  Use brake cleaner as it dries with no residue.  Then clean it again.

[1967 eight barrel]

I would NOT use Brake Kleen on old dried plastic parts. Sometimes it reacts with plastic and will melt it. 
                                                                                       -Keith

[Don Johnston]

CRC Brake Kleen in red can will melt many plastics as it is a tri-chlor. product.  The alcohol based green can is safe on plastics.

[rhjanes]

CRC Brake Kleen in red can will melt many plastics as it is a tri-chlor. product.  The alcohol based green can is safe on plastics.

good info.
I've not done an accelerator cable.  My 1970 428 Mach, has the manual choke.  My old brake clean (don't know brand) and the graphite keeps it working for 10 years now and counting (between cleanings).