I have a 1965 F-100 with a 390, Edelbrock intake and Holley carb. This weekend, during a hard start problem, I accidentally pulled the choke cable all the way out of the dash (wire followed the **** and it flopped around). Following that I pushed the **** back in, removed the air cleaner and tried to see if I had pulled anything loose. Everything looked fine, but this is a new truck and I haven't learned all of its peculiarities yet. Since then, starting has been a breeze, but the engine is idling slightly high and when driving, the RPMS are "sticking" at about 2000 some times, even when no throttle is applied. The result is that I am fighting the transmission and have to apply the brake when stopped or the truck will lurch forward.

Still learning about carbs, so bear with me here. While checking the various linkages, I removed a spring that appeared to be a throttle return spring. The heavily coiled part is now back on the linkage side and the long straight piece is now back attached to a metal bracket, but that could be the problem. In my haste to check everything out I did not note precisely how the spring was connected.

Does this sound like the problem is related to the choke mishap or could removing the spring have somehow caused the throttle to stick? Any suggestions for potential diagnosis or fixes would be greatly appreciated. Thanks!

 

Get the engine warmed enough to run in neutral, then shut the truck engine down and disconnect the choke cable at the carb. Restart the engine and see if the carb backs off to a normal idle.

If it does, I would replace the choke cable. It's probably sticking and holding the throttle slightly open or the fast idle cam in a position that holds the rpms at 2000. I would say there is a good chance that even though you pushed the choke back in, the carb end of the cable did not return to the unloaded position.

 

Thanks to E30tdf for giving me some things to consider.

I looked at the carb and it actually looks to me like it might have an electronic choke. Yesterday when I left work I looked again for the cable and found nothing. What I did find was a black plastic assembly on the passenger side that looked like it might be an electronic or automatic choke.

When I started it yesterday afternoon, there was a lot of fuel puddling around the edges of the air intake and the RPMs were still sky high. Upon closer examination, the spring that holds the throttle closed was attached to a hole closer to the throttle. The throttle was literally bouncing slightly open at the low end, causing the problem. It was also dieseling on shut off. Moving the spring to the proper setting (i.e. increasing the spring tension) corrected the problem. It now starts easy with no choke required, runs smooth and shuts down instantly.

I am still going to have someone work the choke cable so I can see what is happening. It is kind of funny that I had been using a manual choke cable that wasn't connected.

 

If it turns out you have an electric choke, see if it is all connected. Hot wire,ground, and there is a fast idle screw, the lean to rich adjustment...sometimes I wonder which is really the best way.

 

Thanks for the suggestion, I will check the wiring on the choke. I looked under the dash and the choke cable was just stuffed under there, totally disconnected. Kind of funny since I had "used" it several times.

 

I bet you were blowing some serious black smoke out the pipes too! Now it will be a little easier on the pocket book!