I have a 77 F150 with the 351M and an Autolite 2bbl carb. When I start my truck it holds fast idle perfectly at 1350 rpm and then kicks down to 750 perfectly when the engine is warm.

If I happen to bump the gas while monkeying around in the cab on a cold morning the carb comes off fast idle and the engine consequently dies. A restart only puts the cam back on curb idle and the truck simply cannot run that low when cold so I'm stuck there holding the gas for 10 minutes until the engine can run on it's own. Is this normal? Shouldn't the choke keep the cam rotated enough that a restart when cold will put it back on fast idle?

 

I'm dying to help you because it seems that all of the threads you started have been the problems I've had, and then they get solved

2 things you could do to remedy this problem
1: Adjust your fast idle screw
-Hold the vacuum pull off all the way in. Then open the throttle all the way, and slowly release. The end of the screw should be on the "V" part of the fast idle cam. If it isn't, screw in or out to adjust.
2: Before you start it the second time "load the choke" (open the throttle fully, then let slide your foot of the pedal so that it snaps back closed as fast as the springs will make it go)

 

This is happening because your fast idle index is set incorrectly; this is what wycked is talking about in number 1. The end of the fast idle speed screw needs to be starting out higher on the cam; your fast idle is dropping out too fast. There are two screws - the hex screw in the fast idle arm adjusts the index. The slotted screw (the end of which rests on the fast idle cam) is the fast idle speed screw.

Here is a little more detail on setting up the fast idle: https://www.ford-trucks.com/forums/7...ml#post6422219

 

Hey guys, thanks for the replies. FMC...I used that info in your link to get "the Rebel" this far! The manuals and instructions with carb kits are worthless!

Looks like I didn't quite get it right.

Tomorrow is probably the last warm day of 2010 so, I'm all over it. I'll post back what happens.

 

A follow up posting.

So, I studied the tuning info FMC supplied a link to and revisited my carb. I repeated the choke loading procedure over and over to see where the cam falls. This is difficult since the choke housing obstructs the view but a small inspection mirror helps.
My cam has 3 distinct steps and 2 different markings. The cam did fall directly on the "V" marked on the cam...I remember doing this while it was on the bench a year or so ago after I rebuilt it. Come to realize my "V" mark is at the top end of the second step just belowthe high step of the cam. There is another mark at the top end of the high step...looks like an "R" maybe?

My fast idle index screw was backed ALL the way out! I adjusted it so the cam falls on the "R" at the top of the high step on the cam. Ran ok yesterday but I will follow it for a few more days just to make sure.

Either way this would explain my problem. What I was thinking was "high idle" was really the second step or the "warm" stage of the cam. I was never on high idle!