SAAC Forum

The Cars => 1969-1970 Shelby GT350/500 => Topic started by: 66thunder on February 24, 2019, 09:33:56 PM

Title: high idle when warm
Post by: 66thunder on February 24, 2019, 09:33:56 PM
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?   
Title: Re: high idle when warm
Post by: Mongo on February 24, 2019, 09:43:29 PM
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.
Title: Re: high idle when warm
Post by: 1967 eight barrel on February 24, 2019, 11:37:00 PM
CRC-56 is a better choice.
Title: Re: high idle when warm
Post by: Don Johnston on February 25, 2019, 01:44:08 AM
Quote from: 1967 eight barrel on February 24, 2019, 11:37:00 PM
CRC-56 is a better choice.
Yes it is.
Title: Re: high idle when warm
Post by: richflorence on February 25, 2019, 08:04:04 AM
Good info, Mongo. Mine is doing the same thing.
Title: Re: high idle when warm
Post by: rhjanes on February 25, 2019, 08:47:52 AM
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.
Title: Re: high idle when warm
Post by: Don Johnston on February 25, 2019, 01:34:16 PM
Choose wisely to continually use either a wet lube or a dry graphite.  Do not alternate.
Title: Re: high idle when warm
Post by: 1967 eight barrel on February 25, 2019, 07:15:11 PM
If that doesn't help you might see if your power booster has a vacuum leak internally.

                                                                                             -Keith
Title: Re: high idle when warm
Post by: rhjanes on February 25, 2019, 10:54:37 PM
Quote from: Don Johnston on February 25, 2019, 01:34:16 PM
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.
Title: Re: high idle when warm
Post by: 1967 eight barrel on February 25, 2019, 11:32:42 PM
I would NOT use Brake Kleen on old dried plastic parts. Sometimes it reacts with plastic and will melt it. 
                                                                                       -Keith
Title: Re: high idle when warm
Post by: Don Johnston on February 26, 2019, 02:36:14 AM
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.
Title: Re: high idle when warm
Post by: rhjanes on February 26, 2019, 11:21:06 AM
Quote from: Don Johnston on February 26, 2019, 02:36:14 AM
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).