Vac System Removals, 1984 F250

[Starliner]

I have read the great Documents on the Vac Systems that Gary has posted.  I still need help as I see some redundancy to my system.

Feel free to laugh at the color coding.
 Red, (top port), goes to a multi T connector which goes to vac at carb base.  
yellow, (middle), goes to vac advance
green, (bottom one), gets more complicated but it loops back to the same T as the red.

I will stop there for now, it already sounds ridiculous.
Thanks

[Starliner]

This is the more complicated mess.

[ArdWrknTrk]

Color coding is great!

The little Tee in the yellow line is a vacuum restriction. (coming from the green side)
The distributor advance gets restricted vacuum until the thermal vacuum switch senses something above about 225*.
At that point it switches to full manifold vacuum which pulls in a little more timing and steps up the idle.

Increasing idle speed causes the fan and water pump to turn quicker and aids cooling if you're stuck in a hot traffic jam or something.

[ArdWrknTrk]

What do you want to do with the other thermal vacuum valve?

Return it to functionality?

[Starliner]

Jim as far as I can see it hasnt hurt anything to cap it off.
I took the smog pump off, and capped the egr but didnt remove it, just capped the vac line.

On the valve with the hoses, i have vacuume from carb base attached to the top and bottom connections, with the vac advance in the middle. That has to be wrong.

I wish I could post a video to walk through it but I will draw a diagram of the current condition and post it tomorrow.
Thanks

[ArdWrknTrk]

No, that's right for an '84.

Later trucks had 3 port valves, but the function is the same.
You have restricted flow until the wax pellet in the valve pushes the port open and then full manifold vacuum is applied.

It's ALL coming from manifold vacuum. (or base of the carb)

[ArdWrknTrk]

Does your truck still have an emissions vacuum routing diagram on the radiator support or DS valve cover.

Can you take a pic showing the diagram and the calibration code?

[Starliner]

[Starliner]

[Starliner]

What are the odds that I could find a vehicle which has spend 34 years on So. Cal. would be non-cat?

[ArdWrknTrk]

Give us the whole sticker

There should be a bold alpha numeric calibration code on there.


Oh your diagram does show a three port valve with one side having the little plastic vacuum restriction.
So, everything seems normal.

[ArdWrknTrk]

Anything over 8,500 GVWR  NON-CATALYST until 1988.

[Starliner]

[ArdWrknTrk]

Sorry.

I guess I was looking for the code while you were posting

[ArdWrknTrk]

Throttle kicker solenoid..

[ArdWrknTrk]

You've already disabled the EGR and A.I.R. systems.

You have vacuum advance and a vacuum delay valve for the throttle kicker.
Plus the air cleaner temperature compensator.

What's left???

Go have a look at the mess Bill and I had to deal with.

[ArdWrknTrk]

I guess I'm not sure if you're asking a question, or sharing some photos?

You said you 'think you have some redundancy in the system.'
Uh, no.
There was no redundancy when it rolled off the line.

If you could explain what you're trying to accomplish we can help, but none of that removal is going to fly in Cali.

[Starliner]

Will do. I can only imagine. I've seen much of the birds nests.  I thought mine had no charcoal can or other junk because it was born on the east coast. I didnt consider the weight class.

Ok, so to be clear about the temp vac regulator, what should be full carb manifold in, and what should be out or capped?
Should I test this? I got a vac guage from H.F. to adjust the carb, 14 bucks!

[ArdWrknTrk]

Manifold vacuum is going to be dependent on how worn your engine is and how well it is tuned.

You will see the same vacuum through the restriction.
It just builds and falls more slowly.
The same with the throttle dashpot (kicker)
It's there to help moderate engine reaction speed.

[Starliner]

Ok, got it. And wow, looks like the vac routing is fine, I just need to clean the mess up a bit. Thanks all.