I picked up an 82 F-100 with the inline 6 back in October. Did a basic tune up, got the lights working again, still waiting on the license plate lamps to get in(received wrong part the first go round). I've been hanging around here for awhile trying to figure out vac lines and the emissions system in general. Lots of open ports on the carburetor. EGR is unhooked, and non functional. Choke tubes are gone. Both lines off the Distributor are hooked to manifold vac. PCV is hooked right best I can tell, though the breather is gone and the fresh air line hangs down by the oil pan. Truck had factory A/C but compressor and clutch are gone. Carb bowl vent is capped and the line supposed to run to it is laying loose. No air pump, bypass valve, purge control valve, or Ported Vacuum Switch. Also have a bad vac motor on the air tube. No gasket between carb and air cleaner. When I got the truck home all the valve cover bolts were loose as well as most of the manifold bolts.

Along the way I've picked up a Haynes and a Chilton, as well as an 82 emissions/electrical diagnostic manual, 82 owners manual, and a pretty sweet '82 Ford F-series Pickup catalog.

The motor and trans had about an inch of dust and oil sludge when I got it, and I think I've removed about 40% of that, maybe. I got new valve cover and manifold gaskets. Been debating on replacing them now vs. later. Last night made my decision for me, finally found a vac leak and an exhaust leak. I figured between that and not having any idea what most of the unused ports on the exhaust and intake were for, and there being three gaskets under the manifolds, might as well pull them.

Long story short, crashed this train last night, now I need an opinion. Pulled the carb, egr, adapter plate, and both manifolds, called it a night, and when I started in again today I noticed this.

That's coming off cylinder 5. Any idea what caused this and if it indicates more problems? Right up until I saw this I figured the exhaust was fine, had decent back pressure anyway. Also, the exhaust pipe only had one nut holding it on, and the gasket looked like it was made of rust.

Oh and then here's another picture for you. And one more question.
Those lower ports with the freeze plugs in them. What are they for? Accessories?

Thank you for your time.

 

 

Those lower ports with the freeze plugs in them. What are they for? Accessories?

If you're referring to the larger round circles, which you properly identified as freeze plugs, that's what they are there for. Should the block start freezing they get pushed out to prevent the block from cracking. Maybe your thought was there just needs to be 1?

 

Ok you have a decision to make.
Stay with the stock manifold or go with EFI manifolds.
if you with EFI manifolds you will need to get a new Y pipe ant it only comes with a catonverter.
Think I got my Y pipe & cat thru Rock Auto.

If you get the EFI manifolds from a junk yard you can get the Y pipe too.
The Y pipe I hooked to the stock exhaust system as it was almost new.

You then need a way to heat the intake manifold. I got a plate off Ebay that you run got water thru before it goes to the heater.

I have not had it on the road, still building truck, but does run great.
Dave - - - -

 

They are not freeze plugs but everyone calls them that.
They are casting plugs. When the block & head are cast they have sand in the passages and to get the sand out they make them holes.

It just happens when a block freezes if you get real lucky the casting plug, also called an expansion plug, will push and not rack the block or head.
Dave - - - -

 

That exhaust manifold is probably the result of the engine running bad, and whoever was the previous owner just ignoring it and kept driving it. If they had carb problems that cylinder could have been running hot and cracked the manifold. I think you are going to get it running correctly or you are not going to drive it. I would get a new manifold and push on.

Autozone has new manifolds for $167.99. If they have them, I am sure other people have them and you might get it cheaper online, though shipping might be a little steep.

 

 

If you don't have smog check you can ditch most of the vacuum lines.
If power brakes you need that line the most the other you can drive the truck with out but it helps to have them.

As said ported from carb to the advance side of the dist. That helps with power & fuel mileage.
Factory AC needs vacuum to the HVAC controls to work the HVAC doors ie: defrost / floor or dash vents.
The last would be carb bowl vent to keep fumes from getting into the cab.

That is all I have for vacuum lines on my 81 with a 300 six with factory AC.
The EGR has been blocked off and no vacuum line to it. I can fake a line to it if I have to but again it is blocked off below and cant be seen from outside.
Dave ----

 

I habe a 1982 F100 with the I6 300. Below is the underhood vacuum line diagram photo.
You will need to magnify the right hand side of this image to read it.
Sorry it's small - I wanted the whole sticker in one photo and that's what I got!)

 

Got any pictures of your engine and hose routing?

 

My 81 stickers, I have 1 on the project truck and other from the parts truck, have a few less hoses.

Now any pictures would not show all the hoses because of all the other equipment in the engine bay.
Also if you do hook everything back up the way it should how do you know it is going to work right and not cause a running problem?

Know that certain switches flip / flop based on engine temp and others with electrical signal. If a sensor, check valve, or switch does not work as the factory wanted it to you could have issues.
Take the EGR if that valve opens when it is not meant to open the motor WILL run like crap. If the EGR valve will not close the motor will not idle as it causes a large vacuum leak.
I have also seen where the EGR valve was closed but the diaphragm leaked causing a vacuum leak.
In the factory service book it shows how to test every part of that smog system if you want to keep it but also know finding replacement parts will be hard and can take a long time to find.

Mine will not show them because I removed everything that was not needed to run right.
I listed what I have hooked up in the above post.
In my book if not needed for smog check I remove it so it is out of the picture to cause issues down the road.
Dave ----

 

Yeah, my EGR has a diaphragm leak. Rock auto had them for $14 so I picked up two of those and every other emission part they had in stock. Missing air pump, bypass and check valves, as well as Purge CV and TVS(I believe the parts houses list them as Ported Vacuum Switch). Need a new vac motor for the air horn as well. Spent the last few weeks decoding my emissions routing sticker, not sure I've earned my merit badge yet though. Having looked at the manifolds and adapter plate off the truck, I think I can get by with getting the ported vac switch and running all the purge lines from it, into the PCV line that runs to the EGR adapter plate. If that's a terrible idea feel free to yell at me. Still not quite sure what the air pump and related are for, have to do more reading. The fuzzy part of my brain says is puts fresh air through the exhaust to lower exhaust temps for better emissions, maybe something about backfires. It also thinks its supposed to work with a catalytic converter, which I'm almost certain I don't have. Here in a bit I'm going to go out and pull the plugs and run a bore scope down the holes and see what I can see before I order new motor mounts and the exhaust manifold from rock auto, they have them for like $140 shipped.


Almost forgot, still not up to speed on the Wide Open Throttle from the diagram. Not how it functions anyway.

 

From what I under stand on the air pump, my truck did not have one when I got it, it injects air just in front of the cat.
What they say this does is you have un-burnt fuel / no O2 and heat in the cat you now add O2 to the exh. and it burns making it clean out the tail pipe.
My take if you add air even if it does not burn the fuel it will still be clean as you are diluting the exh mixture.

The EGR also sends exh. with un-burnt fuel back thru to be re-burned. They also say it lowers the cly. temps. Well yes it would if you lean out the fuel mix, no fuel no heat!
Then what do I know they do not use either on race cars and why they are not on my truck.

The factory service book also tells you what each system does and when it should work if you want to read it.
Dave ----

 

The EGR does not send un-burnt fuel from the exhaust back into the engine to be re-burnt. It sends exhaust gas back into the engine, which is considered inert, and just takes up space in the combustion chamber. The carb is tuned for the egr to be in place.

 

Does the exh. have un-burnt gas at that point? If it is not pulled from after the cat it has un-burnt fuel in my book.
If it is inert gas and taking up space it is taking that place a A/F mix would be. Because of that I can see it lowering the cly temps.

Now if the carb is tuned for it then it must be rich all the time when the EGR is closed.
Would this not raise the un-burnt fuel PPM high? That sounds like a messed up system to me.

What I find strange is you can remove most of the smog stuff, retune the motor and get it to pass a sniffer test below the set levels for that year.
So why all the smoke & mirrors needed to pass?
Just my .02
Dave ----