OK, it's winter time, and now my truck won't idle when
coming to a stop. Runs fine, mind you.

It's a 302 auto with a Motorcraft carb.

Some damn-fool ford engineer designed the screw
to hold down the distributor (to adjust timing) in such
a position so that apparently one needs a special tool
in order to get the sucker loose, as nothing else has
access. So, I can't adjust the timing. (Who designs
this crap? A special tool for the friggin' timing????)

Sorry - frustrated as hell.

In addition, the Motorcraft doesn't appear to have but
one screw to turn on the entire thing that I can find, and
it doesn't help me out. It's an exposed thingy on the left
(driver's) side of the carb and should affect idle, but doesn't.

I can't find anything on the left side (passenger's side)
that's adjustable.

Any suggestions folks? Love my truck, please don't
misunderstand.

 

Well, at least the distributor is on the front of the engine instead of the rear like on a small block Chevy. Many GM, Chrysler and Ford engines need a distributor wrench. I've had one in my toolbox since at least 1957. On some you can use a universal joint on your socket drive to get enough clearance.
The curb idle adjustment screw should affect idle speed as long as the fast idle cam is not engaged, check your choke adjustment. Due to emissions standards most idle mixture adjustments were covered with a cap of some sort to prevent tinkering.

 

Your engine was designed back in the early 60's. Back then, the bolt was exposed. Over the years it gets covered up with emission stuff and air conditioning compressors.

Try all the simple stuff first, like a tune-up, adjusting the timing, checking the vacuum lines, etc.

But what hit me reading your post and Piffery1's, is you have a truck that old, with the idle mixture screws still covered up? That means that carb has never been rebuilt. It's way over due for one if that's the case.

 

Ah, makes sense. Guess I'll have to buy a universal for my ratchet set.

Tune-ups been done. Vacuum lines look good. It's gotta be the carb,
as it was running just fine.

I think it's running way too rich. Here's more background:

When I first got the truck I forgot to check the gap on the plugs. It had
a miss post-tune-up, and decided to bring it into a supposedly reputable
shop to have them do this and make sure it passes emissions. I told
them four times to check the plugs, but they never did - they did get it to
pass emissions.

But it still had the miss so I pulled all the plugs, found that the passenger's
side rear was closed completely (oops). This fixed the miss. All of the
gaps were re-set to factory specs.

Ran fine, but when the cold hit, it started the stalling. This happens
even when fully warm, when the auto-choke should be off - she'll still
stall coming to a stop. My best guess is she's running too rich, 'cause
this is typical of change-of-season stuff.

Can anyone tell me where the autochoke is on this motorcraft two-barrel?

The only carbs I've ever rebuilt was my 84 VW Rabbit 4-speed. Wasn't
too bad, and it went back together right. I'd rather wait three years,
and bag the emissions crap, air pump, put on a holley/edelbrock combo
and call it a day. Besides, she was running fine (if a bit thirsty - 10mpg).

 

Click this link: http://www.autozone.com/az/cds/en_us...rInfoPages.htm and read the portions which apply to your particular carburetor.

 

The choke is the round black thing on the passenger side of the carb. You can loosen the screws and turn it to adjust the choke. But if your carb has never been rebuilt, then yours may have rivets in it, and can't be adjusted till you get a kit that has replacement screws.

You power valve inside the carb is probably leaking causing it to run rich. Also make sure the air cleaner vacuum lines are hooked up, along with the pipe that goes from the snorkel of the aircleaner to the exhaust manifold. This will draw warm air up into the carb on cold rainy day and make it run better.

 

Franklin2 is correct, a bad power (enrichment) valve would cause the symptoms you describe, ie. stalling, poor idle and excessive fuel consumption but it probably wouldn't pass emissions tests due to overly rich mixture. A bad power valve is usually due to a backfire through the carburetor but sometimes simply due to age.

 

Well, sounds like I better check the choke first - rivets mean I
probably should rebuild the carb. Screws means it's been rebuilt,
and I should go from there and make some adjustments to it,
and maybe the timing.