What's this for?

[OldBlue1981]

There is a pump of some sort that is located on the passenger side fender under the hood. It looks as if it has a total of 3 hoses running from it. It connects to the intake and then underneath the engine somewhere. What is this thing for? It's always running when the car is.

[Lincolnmania]

a picture would help

[Archangel]

Old Blue, are you sure it's actually a pump, and not just the diverter valve mess for the smog stuff?

[OldBlue1981]

a picture would help

Yeah, I know it would. I don't have my digi camera with me. Friends borrowed it for their trip to Florida.

[OldBlue1981]

Old Blue, are you sure it's actually a pump, and not just the diverter valve mess for the smog stuff?

No, I'm not sure. It may be a diverter. It is just running all the time. I'm trying to figure out if I need the thing or not.

[Lincolnmania]

sorry i'm not familiar with the underhood of an 81.....could it be the egr soleniod clicking? do the 81's even have that?

[Archangel]

Well if it's the diverter valve wht you'll be hearing is the hissing of the air going through it along with some vibration sounds from the spring inside it - the actual air pump is under the A/C compressor on the passenger side of the engine, it works all the time (mechanically driven with the A/C belt off the crank pulley) and the diverter valve is the outlet for the air it moves. So yeah, what sounds do you hear?

[OldBlue1981]

It's the diverter then. That's exactly what I'm hearing. So, I don't need that then?

[Archangel]

generally no, it does nothing for the drivability of the car, however it may be necessary for passing visual emissions if you have to deal with that kinda bull. If no emissions you can ditch the whole A.I.R system - pump, diverter valves, hoses, all that should be able to go, just make sure the vacuum lines that operate the diverter valves are properly removed or capped off. I know how to do it on a SEFI 5.0 but yers ain't one, so unfortunately I can't give you tips on what exactly to remove and how.

[Tiggie]

Here's about the only pic I have of my engine compartment (not much to see...). It's all smog junk over there. There's the gigantic air diverter valve over there, and air comes out of that. That's probably what you are referring to. Later cars had it mounted down lower after the smog pump, and a more compact setup.

[Nathan in MI]

Desmogging a carbed car is incredibly easy--much simpler than an SEFI car. Basically just rip all the crap out and cap off the vacuum lines. Only hard(ish) part is plugging the holes on the backs of the heads, and even that ain't bad. Heck, I didn't even do that until I swapped the heads out. Just left the pipe in there and took the rubber hose coming off of it, bent it over and tied it off so it wouldn't leak. Drove it that way for the better part of a year lol

[Archangel]

Heck, I didn't even do that until I swapped the heads out. Just left the pipe in there and took the rubber hose coming off of it, bent it over and tied it off so it wouldn't leak. Drove it that way for the better part of a year lol

Or you could have went to a parts store and spent like $2-3 for a set oh coolant port rubber caps and used the 5/8 one on the one-way valve if it was leaking.

[1987cp]

Or you could have went to a parts store and spent like $2-3 for a set oh coolant port rubber caps and used the 5/8 one on the one-way valve if it was leaking.

Or since he's all skilled with metal and stuff, he could have just brazed or welded the tube shut! :p

[Archangel]

You know, I've noticed that usually when the valve leaks the tube behind it is also rusted out, and rusted thin-wall tubing don't make for nice welds - hell, it's easy enough to burn through nice sheetmetal, I'd imagine welding the tube shut in such a tight space would be a major PITA. I actually took mine off completely and plugged the holes in the heads with 5/8" bolts, tried using 1"-long ones but they still stick oy some, I'm gonna replace them with 1/2"-long ones someday but getting to them ain't easy at all.

[gadget73]

I'm betting he's looking at the canp valve. Pre-1986 they were vacuum actuated. one small plastic cappilary line, and 2 rubber hoses. One to the intake, one to the box under the battery.