Engine idle drops with A/C - Page 2

MPDano · MPDano's Garage

Also, where are you located. It would be best to just swap with a know working one so your not wasting your $$

Yoni_d · 05-26-2009, 07:01 AM

If this valve is also used in other cars then this is what I will do...just buy something similar since I dont live in the US and it does cost a lot with the shipment...

MPDano · MPDano's Garage

Fill in your profile with your location.

Yoni_d · 05-27-2009, 03:49 AM

Done

Danglerb · 05-27-2009, 08:27 AM

Its a 12v about half inch passage air valve. My guess is that any aux air valve that opens with 12v should work.

Yoni_d · 05-31-2009, 01:39 AM

Well, I have some interesting findings...

The valve that i have now is working. the default position is closed and when there are 12V it is open.
The interesting part is that when I disconnect the hose from the valve (the output hose), close it with my finder and then start to remove the finger while the engine is working - the idle starting to drop instead of rise!!!

Does it mean that I have a poor fuel mixture? I have to much air in the system so when I put more air the engine cant hold the idle?

Does it mean that I have to adjust the "CO bolt" so the engine will get more fuel and then when the air valve will be opened the idle will rise?

Or should I do something else?

Danglerb · 05-31-2009, 09:49 AM

Air through the Aux Air valve should come from the same place as air for the throttle comes and goes to, which is metered air. Since you used your finger, I am assuming the source was NOT metered air, try it hooked up correctly.

Unmetered means the air did not pass through the air metering device below the air filter. If it doesn't go through, no fuel is added to compensate for the flow, and no "adjustment" will really fix it, just hook it up correctly.

Yoni_d · 06-01-2009, 12:38 AM

Well, when it is connected correctly, the idle also drops...I tried to connect it directly to the hose from the air meter (bypass the air valve) but the idle droped even more.

Maybe the air valve - that is NOT original, lets too much air to go through it?

Its really confusing...

Danglerb · 06-01-2009, 07:57 AM

Maybe you have a serious vacuum leak(s)?

Are you comparing having the valve connected vs leaving the hoses open to the air?

Post some pictures if you can, but I suspect some things are not hooked up correctly.

Yoni_d · 06-02-2009, 12:54 AM

Yes, this is what I did.
I compared between those 2 cases.

The "output" hose that goes to the engine has a strong vacum but the input hose that comes from the air meter under the air filter seems to be neutral (?). I assume that the output hose "takes" only the amount of air that the input hose provides (according to the air meter)
I didnt see any air or vacum leaks but in the weekend, I will look under the air filter as well...
I will try to upload some picture during the weekend becasue I am busy until then

funny problem...

Danglerb · 06-02-2009, 11:30 AM

Only air that passes through the air meter has fuel added for it.

Any connection below the throttle plate in the throttle body should be "neutral" pressure metered air.

The Aux air valve goes from the base U below the throttle to a port above the throttle. When the valve is open is should be exactly the same as slightly pressing the accelerator to open the throttle.

My guess is that you have some "creative" plumbing, with hoses going where they should not go.

american-kiwi · american-kiwi's Garage

My 78 doesnt have this "electric air valve" from the crossbar either, and it does have A/C

Yoni_d · 06-04-2009, 01:09 AM

Quote:

Originally Posted by Danglerb

Only air that passes through the air meter has fuel added for it.

Any connection below the throttle plate in the throttle body should be "neutral" pressure metered air.

The Aux air valve goes from the base U below the throttle to a port above the throttle. When the valve is open is should be exactly the same as slightly pressing the accelerator to open the throttle.

My guess is that you have some "creative" plumbing, with hoses going where they should not go.

I think that tomorrow I will upload some pictures of my plumbing...
There is so much "creativity" in that car that was done by the previous owner that it just makes me sick.

MPDano · MPDano's Garage

Quote:

Originally Posted by Yoni_d

I think that tomorrow I will upload some pictures of my plumbing...
There is so much "creativity" in that car that was done by the previous owner that it just makes me sick.

We all wonder why these cars were put to so much torture. It's literally mind boggling to see such workmanship being abused.

Yeah, post pics as they are worth a 1000 words.

MPDano · MPDano's Garage

Quote:

Originally Posted by american-kiwi

My 78 doesnt have this "electric air valve" from the crossbar either, and it does have A/C

Yeah, same with Raymonds (rjm65) 79. I did tell him I had some spare pieces of wood lying around and I could Dremel up one if he felt out of place. Same offer applies.

Yoni_d · 06-04-2009, 07:37 AM

I though of something...can someone post some pictures of that air valve area so I will be able too see the hoses connections.
I want to see the input hose origin area and the output hose...
I will post my pictures tomorrow

Danglerb · 06-04-2009, 11:25 AM

On my US 83 the Aux hoses are very simple.

Hose from the front of the intake "body" goes to the Aux valve.
Hose from the Aux valve goes to a Y fitting.
One hose from the Y fitting goes below the base of the throttle body.
Other hose from the Y fitting goes to the carbon canister vent flow valve on the fender.

Normy · 06-04-2009, 05:02 PM

One thing to remember about this guy's car is that it is CIS.

Yoni, if you pull a vacuum line and your car loses idle speed, then it is getting too much air and probably running lean. There is not enough information for us to tell you whether you need to adjust your idle mixture, which is what that screw actually does. In fact, your car might be running perfectly.

M '85 S2 has LH injection, but it also has this vacuum valve. I think it makes a tiny "click" when it comes on with the AC compressor, and the idle stays dead even. This part is your culprit. Have you tried spraying some WD-40 into it?

Good luck. pix will help.

N

MPDano · MPDano's Garage

Yoni_d · 06-05-2009, 09:46 AM

Quote:

Originally Posted by Normy

One thing to remember about this guy's car is that it is CIS.

Yoni, if you pull a vacuum line and your car loses idle speed, then it is getting too much air and probably running lean. There is not enough information for us to tell you whether you need to adjust your idle mixture, which is what that screw actually does. In fact, your car might be running perfectly.

M '85 S2 has LH injection, but it also has this vacuum valve. I think it makes a tiny "click" when it comes on with the AC compressor, and the idle stays dead even. This part is your culprit. Have you tried spraying some WD-40 into it?

Good luck. pix will help.

N

Hi!

I am sorry but I dont know what you mean by CIS...
This vacum part is working perfectly. it makes the click and it becomes open when I turn on my A/C.
Maybe it puts too much air through it since it is NOT an original part.
Anyway, I am uploading some pictures...maybe it will help.