So, I am a new kid on the block and have just bought a 1986 F150 4x4 with the 5.8 carbed engine. The truck has numerous prior issues with the smog equipment, the smog pump was locked up, the pipes that go into the back of the heads were damaged, the valve that those pipes go into was broken, the pipe that goes down to the exhaust pipe was rotted off and there are numerous vacuum lines that are plugged off with some that are just not connected. Some of the metal vacuum lines have holes rotted in them and the carburetor is not the correct original carb. I do not have to worry about passing an emission check and since most of the above pieces were no good, they have been removed. Also the exhaust pipe was almost completely rotted off and is being replaced with no cats. The exhaust down pipe on the drivers side no longer has the flapper valve.<O</O
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My question is what vacuum lines are necessary for the truck to run correctly and what can I remove? I know I need to keep the lines for the distributor vacuum advance, PCV, the transmission modulator, the line to the vacuum reservoir that would feed the HVAC controls, and likely the line that runs to the canister where the fuel tank vents.<O</O
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There are two canisters at the front of the engine compartment and from what I can tell, each one vents a separate fuel tank? I would like to only use one as one already has the plastic piece where the vacuum lines attach broken off. Also there are two small plastic pieces that I believe are labeled as the Purge CV, can I remove these? They have lines that connect one to the other, I would like to just run a line from the carb to the charcoal canister and one back to the tanks with a tee to go to the dual tanks. <O</O
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There is also a piece mounted to the drivers side valve cover with electrical wires and a vacuum line running to it, what does it do, and can I take it off? There are some other pieces on the passenger side of engine with vacuum hoses and electrical connections, can these be removed? On the intake where one of the heater hoses connects, there is a valve with electrical wires attached and a yellow piece with several vacuum lines, can these lines be removed and the heater still function correctly? One more question for now, there are vacuum lines that run to red piece that screws into the intake by the upper radiator hose, can those hoses be taken off and what is that red piece do?<O</O
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Sorry for the long post and thank you in advance for all your help.<O</O

 

Can anyone offer any advice?

 

The emissions systems are a hassle. They had several flavors for each engine, and different ones each year. A bunch of abbreviations also.

The first thing you need to do is study the diagram stuck on the radiator support. It will have everything listed that was on your engine. You can then look at this site, and decode what the abbreviations mean. Automotive Dictionary - 'AA'

Will it take a lot of your time? Yes. But you can learn a lot about it.

 

The only lines necessary are; the speed control line, the vacuum modulator line for the transmission, vacuum advance for the distributor, the brake booster and the one that runs to the hvac controls.