engine bogging/vacuum problems

[DavidD]

I usually dont post much on here. Cause I usually dont have any problems with my X. But today I had a problem

First of all I have a 92 XLT with around 130k miles on it. When I started my X to go home tonight it started bogging real bad and tried to die on me. The whistling type sound let me know it was a vacuum issue.

I found the culprit after feeling around for a couple of minutes. It was the vacuum tube behind the big hose that goes to the brake booster. I didnt know what line hooked up right there so I just plugged it up. Once I plugged it the X was fine. But I noticed 2 disconnected vacuum lines from there (behind the intake manifold). One of the lines was about half inch in diameter and 1 1/2 feet long and was hanging under the brake booster. The other I believe was going to that cylindrical looking object next to the foil covered thing having to do with the A/C.

I also noticed that from the small round canister located next to the brake booster there was a small line that looked wet with what appeared to be either ATF or Brake Fluid. It had sprayed on the hood and on the brake booster.

my questions are do I just leave the plug on the vacuum spout or do I hook up one of the lines? which one? what do I do with the other lines? Why was there fluid sprayed in there? why is it sunny during december in Cali?

Thanks and sorry for the long post. I was just trying to be as detailed as possible.

 

[jimbo74]

i have no idea, but i live in cali and we have rain!

 

[Howard]

The only way ATF gets up a vacuum tube is via the modulator valve on the gearbox. Relatively cheap and not too dificult to replace. Hope this helps.

 

[Opera House]

Search for the post

"Vacuum modulator replacement." This gives a good procedure for replacement. The hoses get weak from the fluid and should be replaced. Could also use clamps or ty-wraps to secure the old hoses. Modulator is only $12 at bulkpart.com and they have $10 SPX filters if you get in the mood to drain the transmission too. You shoud notice that the transmission is shifting higher than it used to.

 

[SteveVB]

The vacuum line under the booster is most likely the cruise control - it should be hooked up to the tee at the back of the engine. The ATF is from the vacuum modulator as pointed out before. The ATF may have caused the hoses to loose their grip on the fittings, you should replace the hoses, or maybe clamp the existing so you dont have further problems with the hoses blowing off.

There are no vacuum lines which should just be hanging- which if I read your post correctly- you have capped the vacuum tee, and have two lines that have no place to connect? Check your vacuum tee, for an open port, I think that all of the ports should have a hoseattached- except for one which is capped.

Can you get a pic of your engine compartment? specifically the vacuum tee area, and the brake booster/speed control area, or the other area you mentioned by the A/C

Good Luck

 

[X-1]

Tranny fluid from a bad modulator valve will cause the rubber hoses to slip off, and will eventually destroy the rubber lines. After you replace the valve, I would suggest replacing the rubber hoses and fittings, I went thru the same exact thing.

 

[DavidD]

Thanks for all the help guys. As requested by Steve, here are some pics so you guys know what Im talking about. Just click on the link and you will see the list of the pics

Dead Link Removed

I still dont know where to hook up the lines...HELP!!!

 

[SteveVB]

Pics are great!! Easy to see whats going on.

Ok David,

What you are calling the second hose should be attached to the port you capped. There should be only one capped port from the factory.

The other hose is from your speed control servo I believe, the end that is hanging loose should go to a big drum looking thing to the right of the brake booster thats mounted on the inner fender- you can see it in your "where does this hose go"pic. Take a look at the drum, it will have either a fitting, or maybe a hose with a fitting(check valve) on it that needs a mate- it should be obvious.

Replace the hoses as suggested, and get a new vacuum modulator installed, you should be good to go. I cant imagine the engine is running too well right now, but fix the vacuum leaks and the modulator and you should be in good shape.

Good Luck.

 

[DavidD]

Thanks Steve, I hooked up the vacuum lines early this morning before heading out. I kinda figured out where they went and just hooked them up, it worked, but I was still kinda worried as to wether I had hooked them up right or not. But you have confirmed that they are hooked up right.