Help! Where does this vacuum hose belong?

[nads83]

Bad starts, a suddenly bad idle led me to dig around my 1983 5.0L for a vacuum leak. Think I found the culprit- an unattached vacuum hose. When the car is cold, plugging the hose causes the car to nearly stall out. But when the car gets warm, plugging it makes the car idle well. What the...Where does this thing belong?

I think its a 1/4 inch and has a red stripe. The hose starts on what looks like a ported vacuum switch attached to the intake manifold behind the carb, just to the right of the EGR valve. The switch also has a piece of what looks like heater hose off the top that goes to a multi-hose relay on the firewall and then on to the power brake cylinder.

I tried to interpret the emissions sticker under the hood but I couldn't understand it!

Thanks!

[Marz]

Under the air cleaner base. Good possibility. There is a little valve with a nipple sticking out that it could attach to. Sometimes

Also, is your car an Automatic or a manual?

It's easy to read the diagram. Just take your time. It's fairly easy once you understand it.

[nads83]

Thanks- its a 5 speed. Been looking at diagrams for hours and I think you're right about it being under the air cleaner.

When looking at the diagram, is that the air cleaner assembly shown seperately to the right? I'm not sure about all the abbreviations.

Thanks again.

[85stanggt]

From what you describe and if it does have a red stripe on it, that is the manifold vacuum line to the air cleaner. It should plug onto a tan plastic piece on the driver's underside of the air cleaner. This is a very likely thing to have hanging off, because it must be disconnected in order to remove the air cleaner from the engine to do work on it.

On my '85 diagram, I have a small hexagon in the upper right corner labeled "Man Vac". The tube coming off it from the top goes to a piece in the diagram labeled "A/CL CWM". That is the green piece you see on the back of your air cleaner. The tan hookup piece for your red stripe hose is between the "Man Vac" and the "A/CL CWM". You'll see what I'm talking about when you take a look at it.

[nads83]

Thanks for the inf0- definitely belonged to the air cleaner.

Still weird though- to start, I have to disconnect the hose. When it warms a bit, I have to hook it back up. Otherwise idle is rough.

Anybody have any ideas?

Thanks!

[Muscleford]

Temperature sensor is likely bad.

[JACook]

Most likely the choke pull-off has been maladjusted, and is not cracking the choke open
wide enough. Leaving the hose off allows it to bleed air into the engine, countering the
rich mixture. On an '83 4180C, the choke unloader adjustment on the choke housing, at
the base of the cylindrical part that hangs down.

(That's presuming the choke cover hasn't also been made adjustable, and then maladjusted...)