OK so see if you can figure this out...I have finally got my truck back together after the roll over on the highway last fall. (390) new cab mounts , shocks , clutch , intake , headers , exaughst , on my recently(before it was rolled) rebuild motor. All these new parts and all these new noises. Anywho, I finally get the guts to take it out of the trailer park and on to the highway. So after driving up and down a 2 mile stretch of road all day just adjusting and test driving and listening and test driving I decide the truck sounds pretty good after sitting a year. I am kinda leary about driving it scince I rolled last year and had it all apart. I decided to have the old man come with on a test drive. I had him drive.
So we are leaving the trailer park and he starts out in 2nd and puts his foot in it, then 3rd and he is still into the trottle pretty good, and then 4th with his foot all the way in up to 70 mph. Much faster than I dare go in her yet!(76 f250 highboy with 4:10's)
After we make a turn into a developmet she is ildeing way high! I cant find any vacume leaks,the timing hasnt moved and if I turn the idle screw down it still is high. Checked the floats,choke(manual),and it is a new carb aside from sitting for a year while it was being reborn.
I cant for the life of me figure this out. It happened after the old man beat on her.

Any thoughts?

 

Can you push down on the back of the throttle, on the carburetor, and have it go back to normal? Sounds like something either caught or bent in the throttle linkage.

 

You didn't say, so I'm just guessing it has a 4bbl carb.

You were nervous, never had the secondaries open.
He wasn't nervous, the secondaries didn't close all the way.

I think Rusty's on the right track, the linkages for the high idle cam (behind choke housing) and the secondary interlock (same side as idle adjust) can jiggle out of place and make things interesting.

Another possibility could be residue (varnish, oxidation) build up from sitting. I wouldn't be surprized if a few shaft mounted parts were gummed up. Did you take the carb apart and clean it before start up?

I know, I know, all those pesky details! Don't feel bad, I had to learn them first hand my-self.

Good luck, Mike

 

I'm betting on the varnish on the secondary shaft!

Spray carb cleaner profusely on the primary and secondary throttle shafts while working them manually to free them up.

 

I'd also check to see if the throttle blades are loose. I have seen that before. Sounds like you might be well off to just remove the carb, clean it well and tighten the blade screws. Also, if you have 1 year old gas, you'd be wise to drain the tank and start with fresh stuff.

 

secondary linkage!!! now that makes sense...This weekend ill try cleanin things up a bit. Great advise!!!