This is on a 1980 302 with a missing tube from the air cleaner horn to exhaust manifold shroud.
The factory service manual calls out Clamp 386311-S8 and Tube 9B632.

I was going to scour local junkyards, but may have more luck with part numbers.

Or I could maybe get by with flexible exhaust tubing. I think 2" ID.

The truck is running rough, I thought I would at least put all the parts back on it before going further.

 

That tube helps it run better in cold weather. It's good to have it on there, they sell the aluminum flex tubes in the store that work fine.

Not sure if it's going to fix the running rough issue but you can try it. Once you get it running after a cold start, stick your hand up in the snorkel of the air cleaner. The flapper door should be shut or partially shut right after a cold start. If it's not, your tube is not going to do anything anyway.

 

Once you get to a point where you need that tube, I put up a page on my web site to answer the question: Air Cleaner Heat Tube - ???Gary's Garagemahal.

But, you are right that it is 2" tubing, and I would think that exhaust tubing might work well - assuming you can get it to conform to the twists and turns that are needed. I think that's why Ford used the paper/aluminum stuff.

 

They sell that flexible aluminum tube at the auto parts store.

(If they don't stock it anymore, look in Motormite)

 

C9UZ-9652-A (replaced E3TZ-9652-A) .. Hot Air Tube-aluminum and paper composite / 2.00" I.D. x approx. 18.00" long - cut to fit / Available from Ford & auto parts stores.

Myriad 1969/96 I-6/V6/V8 FoMoCo vehicles.

Note to OP: Parts catalog sez: 9B632 > Improvise from C9UZ-9652-A and notice in the pic that the clamp is basic number 8287, this is a radiator hose clamp.

 

Yup, as said here:

 

Dorman Air Intake Pre-Heater Hose 96024- ReadReviews onDorman #96024


And being we are on the air filter hose thing here is the fresh air hose from snorkel to radiator support.
Dorman Fresh Air Intake Hose 96052- ReadReviews onDorman #96052
Dave ----

 

That's just one of the fresh air hoses. See all of them here: Air Cleaner Tube #'s - ???Gary's Garagemahal

 

I picked up a hose at NAPA, already had a couple clamps. But you are right on point, there is no vacuum present at air cleaner valve. Now the engine was cold, but outside temperature about 80. There is vacuum going into air cleaner sensor, but not coming out. Should it have operated under that condition?


Of course, this truck is running so rough it dies at idle until warmed up, so being just me, I have to run from cab to hoses before it dies to check for vacuum.

 

It would depend on what Air Cleaner Temp Sensor you have installed, as explained here: Air Cleaners - ???Gary's Garagemahal. But, almost all ACTS would be open at 80 degrees and, therefore, close the flapper and bring in hot air.

So, it seems like you have a problem. If you have vacuum to the air cleaner but not to the flapper motor then you may have a bad ACTS or Cold Weather Modulator.

 

Most of the time I get them working by prying the plastic cover off, and then messing with the mechanics of the sensor. You can see how it works once you take the cover off. Messing with it and forcing it to work with your fingers seems to get them going again. You can also fiddle with the adjustment screw, and sometimes that will get it working again.

Once you get vacuum to flow through and the flapper shuts, make sure the flapper opens when the air cleaner gets hot. If it closes the flapper but then the flapper won't open back up, then the vacuum hoses are backwards on the sensor.

Running rough when cold, and ok when warm sounds like a choke problem on the carb. Another can of worms and a whole system to learn about to get it right.

 

Don't forget to check the flapper's motor. Those are frequently leaky and won't work with the minimal vacuum they are given via the ACTS.