Rod Underwood

I'm still working on the funky 82 and have checked this part for vaccum and it holds it, it also has no vaccum when the car is running.

The next most important question is: WHAT IS IT and SHOULD IT BE CONNECTED TO SOMETHING?

My 87 has something similar and it has a hard vaccum line connected to it, but it's buried and I can't see where it goes.

The WSM hasn't provided any identification so far, can anyone help?

Thanks
Rod

hacker-pschorr

IIRC it has something to do with the gas fumes / Charcoal canister / air pump emissions system.

Whatever it’s called, my 81 no longer has one. If it's not causing a vacuum leak, I doubt it has anything to do with your issue.

Have you tried the break cleaner trick? That is how I found my massive air leak. Buy some good quality break clean (stuff that is mostly isopropyl alcohol - leaves no residue) - using the coffee stir size hose, spray everything that has any kind of seal. If your idle speed changes, you just found a vacuum leak.

Since you were spending all of the 4th weekend working on the car, should have brought it up here!

Dennis Wilson

Rod,

It appears to be the EEC (evaporative emissions control) valve that controls the fuel vapors from the charcoal cannister and the fuel tank. Not sure about your 82 but they typically have a manifold vacuum line connected to the small port at the end and two larger ports connecting to the intake manifold and fuel tank. It appears that yours has been disabled.

Dennis

Rod Underwood

I've tried spraying the engine on three different occasions. I can't imagine I have a big vaccum leak that hasn't shown up. I used a whole can and drenched everything last time without the slightest change in idle speed.

Rod

Mrmerlin

Hi you may have found the vacuum leak try to find the hose that this vacuum diaphram connects to, if its plugged try reconnecting it, also look under the intake with a mirror on the passenge side, look for a thick metal tube that runs to the back of the engine then look for any hoses that may be touching this metal line, any hose that touches the line will probably be burned as this line has exhaust gasses running thru it, re[place any lines that are suspect

Dennis Wilson

Rod,

Might be worthwhile to check the hoses at the charcoal cannister.

Dennis

Rod Underwood

At this point, I have no old hoses anywhere under the plenum. I will disconnect this vaccum valve from the line and plug and see what happens. It does have vaccum on the engine side, obviously, but I can't detect any leak anywhere else. What are the long term ramifications, if any of disconnecting and plugging this line?

It sounds like Hacker has removed his completely with no ill effects. Of course he is selfishly not giving me his blower, which apparently solves the problem.

Rod

PorKen

That's the vapor recovery valve. It should have a small hose that goes to the ported vacuum on the back of the TB, by way of a thermo-valve installed on the heater hose connection at the rear of the right cylinder head.

While you're capping and plugging, remove the vacuum limiter (if still installed - the flying saucer shaped thing on the side of the TB), and plug with 3/4" and 5/8" heater hose blockoff caps. It can give you problems, and is not necessary.

Scott M.

Rod;

As Ken points out... my lines to the vapor valve have always been a small red rubber hose.

Yank it!!

Rod Underwood

Thanks, I removed and capped the vacuum limiter about a month ago. Still having the idle problem approximately 45 seconds after start up. Once I get by this balking, everything is clear sailing from then on. Even after removing, capping, swearing, etc. all this stuff. There's hardly anything left. How about a brain problem, mine or the cars, either one?

Rod

Rod Underwood

Thanks, it's long gone.

Rod

Dennis Wilson

Rod,

A vacuum leak, unless really big, would cause a high idle rather than stumbling. A low stumbling idle when cold, sounds more like a nonfunctioning AAV.

Dennis

Rod Underwood

Actually I have temporary removed the AAV and it made no difference. At least I'm getting more room to work on the engine with all of the items I've deleted. ;-)

Rod

Dennis Wilson

Rod,

The AAV is supposed to open and give more air during cold starts to prevent the stumbling. Did you plug the inlet and outlet lines?

Dennis

Rod Underwood

Oh yes, they're well plugged and it was the second AAV that I'd tried. I know it must be something that I've already tried since I have very little left. Maybe a new engine?

Rod