sam

This past weekend, I had a few extra moments under the hood of my 924-S, so I decided to put my newly-fabricated intake system pressure tester to use and see if: it worked, and if I had any intake leaks.

Well, the water/soap solution showed that I indeed had 2 leaks which showed up under pressure. One of them I fixed by replacing one of those hose crimp-on type hose clamps with a screw-on type. The other leak (a big one) kinda has me curious. The leak was coming from the idle stabilizer housing cover where the wire connector is made up to it. It was actually pissing a lot of air. I don't know if this is normal (remember it normally operates under vacuum, not pressure). Previously, I had a stethoscope and had trouble figuring out where the noise was coming from. No wonder, I didn't think wires would do that.

Anybody have any thoughts on this? I would think that this may very well be my false air which is messing up cold idle. <img src="confused.gif" border="0">

webberman

It should not leak. I've done the same soap and air pressure test with my 951 looking for boost leaks and found my stabalizer leaked as well. I replaced it. Repeating the test with the new one did not reveal any leaks there.

sam

What??? Ya mean I'm finally gonna have to replace that thing? I've been cleaning it everytime I have the intake off, and have managed to keep it functional (except for this leak).

webberman, did replacement of it solve whatever problems that made you do the test in the first place? What were those problems anyway?

adrial

Sam, how did you fabricate it?
I've read that a cut up fuel filter in the intake manifold works well...(recommended in the factory manuals)

I'd like to do the same to my car soon.

thanks,
Adrial

sam

adrial

Talk about easy! a 2 inch PVC waste and drain fitting will fit exactly indide the boot with the air flow meter removed. I used a 2 inch cap, drilled and tapped a 3/8 inch NPT swagelock fitting into it. Connected a piece of 3/8 Copper tubing, and added a 1/4 inch globe valve on the end. To the globe valve, I added a standard quick disconnect fitting to connect to my compressor.

If ya do this, make sure the valve is closed before you connect the air. While I didn't do it, it seems like it would be easy to pop a whole bunch of stuff apart.

This was fairly simple. If anyone who is interested, I'll take a pic of it and send it too them.

I saw some of that stuff about fabricating a plate to fit where the filter housing should go. Too much trouble, besides, the rubber stuff is what is gonna leak.

sam

adrial

Talk about easy! a 2 inch PVC waste and drain fitting will fit exactly indide the boot with the air flow meter removed. I used a 2 inch cap, drilled and tapped a 3/8 inch NPT swagelock fitting into it. Connected a piece of 3/8 Copper tubing, and added a 1/4 inch globe valve on the end. To the globe valve, I added a standard quick disconnect fitting to connect to my compressor.

If ya do this, make sure the valve is closed before you connect the air. While I didn't do it, it seems like it would be easy to pop a whole bunch of stuff apart.

This was fairly simple. If anyone who is interested, I'll take a pic of it and send it too them.

I saw some of that stuff about fabricating a plate to fit where the filter housing should go. Too much trouble, besides, the rubber stuff is what is gonna leak.

sam

damn hick-up. Sorry for the double post.

951Tom

Sam,
Can you post pics of your intake leak finder? I've been patiently waiting for my fuel filter replacement, but I've got another 10K to go. What pvc did you use? The inside boot diameter looks to be more than 2 inches? Thanks.

sam

There is nothing real complicated. Get a 2 inch PVC, schedule 40 DWV cap. Go to lowes and tell them you want to cap a piece of 2 inch PVC. The cap fits beautifully on the inside of the boot. It'll cost you less than a $1.00. Now you have to figure out how to connect the air.

The only caution is, I would (and did) put a valve. It doesn't take much airflow to see the boot expanding. I didn't want to start popping hoses. That would be a real PITA

adrial

Did you cap off the exhaust or did the engine (and in my case turbo) create the necesary back pressure?

sam

Adrial, the 924-S is an N/A. Can't tell you much about the turbo implications. I didn't see any reason to worry about the exhaust with my vehicle. I didn't have to crack the valve very much to achieve the results I was looking for.

I would think it would work on a turbo, but I can't say for sure with all the extra plumbing.

I was of the opinion that my air leak was enough to give cold idle problems, but not enough to give warm idle problems when the thing is in a closed loop. My warm idle is good, cold was a problem.

I noticed the recommendation on my previous post of a number of months ago, that the exhaust should be plugged also. I guess that may be for the turbo models.

Hope this helps. It did what I wanted it to do.

sam

Adrial, the 924-S is an N/A. Can't tell you much about the turbo implications. I didn't see any reason to worry about the exhaust with my vehicle. I didn't have to crack the valve very much to achieve the results I was looking for.

I would think it would work on a turbo, but I can't say for sure with all the extra plumbing.

I was of the opinion that my air leak was enough to give cold idle problems, but not enough to give warm idle problems when the thing is in a closed loop. My warm idle is good, cold was a problem.

I noticed the recommendation on my previous post of a number of months ago, that the exhaust should be plugged also. I guess that may be for the turbo models.

Hope this helps. It did what I wanted it to do.

sam

anybody know why this is repeating itself when I post? That is twice in one day now. With all the posts, someone may think this is a hot topic.