Here's the vacuum diagram for my truck.


I'm trying to put it back to stock, if that's reasonable, after putting a junkyard engine from an '86 in. The hoses had been changed around on the old engine, and some stuff is missing, such as the "HICV." I've searche the web and this site, and haven't found a reference to this. Anyone know what it is?

I'm also unclear about which parts are referred to in the upper left corner; A/CL DV: Air Cleaner, what?

Thanks for any help,

-Mark

 

Mark,

I too have an `85 460 but I have pulled all my stuff off since it was all non-functioning anyway. Every vacuum hose and diaphragm was dry rotted. I do still have the PCV but I am almost positive that it was hooked directly to manifold vacuum without going through any other device.

I think the A/CL is the flap in the air cleaner snout that directs either fresh air or warmed air to the air cleaner. The vacuum goes through the bimetal switch in the air cleaner to signal the flap when it is warm enough in the air cleaner housing to let fresh non-warmed air in. But, there is also a secondary opening that is vacuumed operated that lets fresh air in so it could be that too.

If this stuff isn’t needed for emissions testing I know I would not try to put it back on.

Good luck,

Mark

 

Mark,

Thanks for the info. Oh, it definitely is needed for emissions. They test your vehicle every year here in Arizona, and inspect the emissions equipment.

Mine also has the PCV valve connected directly to the large port in the base at the front of the carb (which, by the way, is a 4180, if I recall correctly), but I wouldn't bet that that was the way it was originally set up. There's a newer chunk of heater hose where the HICV is shown to be.

I've still got to locate the charcoal cannister that I think I took off when pulling the old engine...

 

Guys, since we are currently dealing with the same vehicle. I need your help with a 85 F250 with 460 and standard. we just(last night) put a long block engine in it. We have removed all of the vacume lines except egr, vac advance. etc. My question is on the passinger side of the engine compartment just back from the radiatior on the frame is two little boxes Charcoal canisters?? I think. we are going to remove them but their is a tube that goes from one of them to the rear fuel tank. What is it and secondly what should I do with it.

Thanks,

Adrian

 

Adrian,

Yes, that sounds like the charcoal canisters. Vacuum from the engine pulls vapor through that small tube running to the rear tank(s). You can remove the canisters, leave the tube, and the tanks will be vented into the atmosphere.

Mark

 

Great! Thank you Mark very much!!!

since we removed all of the other vacume stuff. Any thoughts or suggestions from prior experiences of removing that stuff?

Thanks again

Adrian

 

Adrain,

What are you looking to remove?

Mark

 

Mark,
Well, there is one air pump and I don’t know what the other thing is they are right above the alternator just to the passenger side of the fan that we were told that the we could live without. One was frozen anyway. We took the remaining vacuum lines that were connected either off or pluged them off. And that is what we removed. I hope my rambling on makes sense. Basically the truck will just be used as a farm service truck to haul welder air compressor misc parts here and there. All we really want under the hood is engine carb and just the necessities to make it run. The simpler the better. Any thoughts or cautions?

 

Adrian,

Both of the devices above the alternator on my truck were air pumps. One for each bank of cylinders. If your truck has a cat then your setup may be different than mine. Unfortunately, the air pumps share a bracket with the alternator and when you remove the pumps you are left with a monstrous big bracket. I found a used car alternator bracket and was able to get ride of the other.

I have removed all emissions equipment except PCV. To get rid of the EGR you will need to re-jet the carb (if it has the Holley I don’t think it can easy be modified) or even better go with a non-EGR carb. I went with an Edelbrock 1406 600 cfm unit. Big improvement over the junk Holley that was stock.

If you keep the EGR then make sure it is still functioning and the vacuum hoses are not dry rotted. Hook it up the way Ford did it and you should be okay. The EGR is not a big deal but it needs to function or you will get pre-ignition under light load. To remove it and not have pre-ignition you will need to have a richer mixture than the stock carb.

My air pumps added oxygen to the exhaust manifolds through stainless steel tubes. Yours may add oxygen at the cat (if you have a cat). If you remove the air pumps and you have a cat then you will probably need to remove the cat too since it won’t last long without the added air.

The vacuum line to the distributor should be connected to ported vacuum on the carb. Ported vacuum does not have a vacuum signal at idle but it does above idle. Also make sure that the diaphragm in the vacuum advance unit of the distributor is not leaking air. Simply put a piece of hose on it and suck on it with your mouth. If it is leaking then you will be able to draw air through when you suck. You should not be able to draw any air.

Your local auto parts store should have assortments of rubber caps to plug the various line connects on the manifold that are no longer going to be used. Make sure each is blocked otherwise you will have a huge vacuum leak.

One last thing. The ignition timing can probably be set a few degrees higher than stock. Try 12 degrees and see if you have any pre-ignition under load. If not then move it up in 2 degrees increments and retest. You probably won’t be able to get past 16 degrees. Once you find where it pings then drop it back one degree - or two if you want to be safe. Higher initial timing advance will give you noticeably better low end torque.

I hope that helps but ask if you need anything clarified.

Good luck,

Mark

 

Mark…you’re a genius. What I have done and what you said are exactly the same. I do have another question. On the rear of the engine there is a tube that goes from one head to the other. Since we removed all of the other items do we just plug it…at say right above where they join above the little canister type thing. I am just not sure what to do there.

The engine is the same as yours it doesn’t have the cat. It has the stainless steel tubes.

The only vacume lines we left is the one going from the distributor to the carb. And under the carb is a plate with a brass thing that has a place for a vacuum line on it. The line went to the manifold vacuum tree for lack of better words. I hooked that up. Should I leave it???

This evening after work we are planning, hoping, crossing our fingers, praying… that the engine will run.

Thanks again,

Adrian

 

Adrian,

The rear tubes can be left as they are. There is a one way flap or valve so nothing will be leaking out of it and there shouldn’t be a problem with stuff getting in. If the motor were still out of the truck you could pull those tubes and block off the openings in the back of the heads with a small freeze plug type of cap. With the motor in the truck there isn’t enough room to get back there to do it. So, just leave them the way they are. You can look on the front of the heads to see the small freeze plug if you are curious about them.

I have left my stainless steel tubes because the fittings at the manifold are too rusted. If you can get yours out just get a cap and screw it in the manifold to close off the eight openings. Not a big deal to leave them, but it does make it a bit easier to pull a valve cover without them there. If you need to pull a cover simply remover the bracket on the valve cover and pull the whole group of tubes out from the motor a bit – not far but a little and it will free up the area to get the valve cover off. And since I mentioned it, if you do keep these tubes then you will need to keep the support bracket that attaches to the top of the valve cover. Without it the tubes will vibrate and snap off.

The plate under the carb should be the EGR valve. There should be a vacuum diaphragm on the back of it where the vacuum line hooks up. You can suck on the vacuum line to make sure that diaphragm is not leaking but you will also want to make sure the EGR valve is opening and closing properly. If it does not close completely then it will be re-circulating exhaust gases all the time and that will make for a rough idle. According to the decal the EGR vacuum line goes through a switch (labeled VCV and switch based on coolant temp) that has a carb vacuum line (port E line color white) coming to it too. I suspect that carb line is ported vacuum but I can’t tell if anything else connects to switch VCV. You may want to recheck the hook up of the EGR.

If you can find an alternator bracket you can get rid of the monster bracket. As I mentioned I used one from a car but added aluminum spacers to move it out enough to clear the sub frame and align with the crank pulley. That cleaned up the engine compartment a lot.

Sounds like you are on the right path. Good luck with the fire up and have a few cold ones ready.

Mark

 

OK, now that Adrian has finished hijacking my thread... can we get back to the question I posed originally? I cannot remove any emissions equipment in my state, and I'm STILL wondering what an HICV is.

 

Have you checked with Ford?

Mark

 

Well...I will keep this short. The pickup ran well. We had the carb guy work his magic on it this morning. Thanks to all!! Especially Mark. Since we are all for the common goal of having our Ford run the best it can.

Thanks again,

Adrian

 

Answer to a couple of the above questions:

1) the PCV comes off of the big port on the front of the carb.
2) The 4180 is extremely easy to rejet if needed.
3)Hell if I know what a HICV is? I'll try to look this week end. It may be some sort of electric type deal? I rember that there were some wires going into my vacuum lines and not knowing what they were.

Good Luck.

Larry