Hi again,
After investigating, I found a vacuum tree mounted on the driver's side rear of the upper intake manifold that was missing (maybe) two hoses. I don't know how they could have come off. I found one hose that connected to some sort of vacuum "can" next to the power brake booster, so I reconnected it to the vacuum tree. But there is another port on the back of the tree that's missing something. I can't find any other loose hoses. Maybe this port just gets blocked off?
I looked in all the books I have and this "tree" is called a diverter valve-vacuum motor. But there are no clear pictures or diagrams that show all the connections.
This tree has 7 ports on it. One goes to the power brake unit, one to that vacuum "can",one that has something to do with the A/C, and the rest are too hard to follow.
Anyone with a 92 explorer out there?
Let me know if the rear most ports have hoses connected to them or maybe one is capped off.
Thanks,
Joe

I think i found what you were talkin about and i had a tube comin off the front side of it just one

Joe-
I have a 1992 Explorer and I was wondering the exact same thing. It was idling rough so I looked around under the hood and found that back recepticle on the vaccum tree had nothing on it. I looked for an unconnected line to put on it and couldn't find anything. I plugged the hole with my finger and the idle smoothed out. I assumed it previously had some kind of rubber cap on it...which must have fallen off. As tacky as it may be, I used a golf tee to plug the recepticle and it hasn't given me any problems since. I am not sure if that was the best solution, but I works.

Joe-
I have a 1992 Explorer and I was wondering the exact same thing. It was idling rough so I looked around under the hood and found that back recepticle on the vaccum tree had nothing on it. I looked for an unconnected line to put on it and couldn't find anything. I plugged the hole with my finger and the idle smoothed out. I assumed it previously had some kind of rubber cap on it...which must have fallen off. As tacky as it may be, I used a golf tee to plug the recepticle and it hasn't given me any problems since. I am not sure if that was the best solution, but I works.

Yeah, I just plugged it also and it's been running just fine. I guess, like you said, it must have had a cap or something on it.

I also had this same exact problem (starting to think there's a reason everyone says that at the beginning of this reply) Iwish would could find out exactly what the thing is -

I bought a vacu-tite vacuum cap at an auto parts store - looks like the same thing you put on the tire valve stem to prevent leaks almost - just slides right on. BUT, now I have a severely noxious and most likely toxic fume problem inside my truck. I got really sick and had to shut it off and get out. Only started after I covered that mysterious vacuum hole. Yet, my engine problems completely stopped when I covered it too. If anyone has figured it out please let me know because now it sounds great but with that fixed it's probably deadly to drive in. :disappoin

LIke the rest of you, I too had same problem on my 92. The fix was the rubber cap. Also be aware that the other may have also come off the manifold vaccum tree, but because the others have a vaccum line attached to it, it didn't fall on the ground. What you may also find is that the insides of the rubber are oily and that's one of the reasons they popped off. Be aware that if your car backfires while starting the engine you may want to pop the hood and check the cap and connectors on the tree. For good measure change your PCV, that may have something to do with oil getting into the insides of the rubber cap and connectors. I haven't had any problems since. Many of us overlook the PCV.

As to the smell, you didn't mention if it was gasoline etc. Most smell that is potent smelling is antifreeze leaking at the heater core. Check your coolant level. Also look on the front passenger floor to see if it's wet. Be sure that you engine is hot and that you have turned on the heater first. Then shut off engine and get a flashlight and lift the carpet away from the firewall and look for antifreeze leaks. The only other thing is a valve cover that is leaking oil and the oil drips on the exhaust system and with the fumes coming into the car via the vent system (hood cowl).

The smell was never there until right after I put the cap on the vacuum and started driving. It was foul - I want to say like eggs I've heard that before but I'm not positive. It wasn't really like gasoline more like garbage or something I guess egg is the best description - I got a bad headache from it though.

I'm just learning all this stuff as I go - but maybe the smell means the PCV is bad I've heard that mentioned before with emissions - but would capping the vacuum bring that out in the open through the smell?????

If it's smelling light rotten eggs it would be sulfur. that would be a indicator that your catalytic convertor is gone. Capping the vaccum leak would not cause that smell. Maybe someone else has a better idea on this forum.

Well, thanks for the ideas guys. Sorry to hear about that nasty smell, mine doesn't do that. But the other day the vacuum lines popped off again. This time I did what someone else suggested, I used tie wraps (those zip tie things). I'm hoping that will perminently cure it this time. However, I'm definately going to change my pcv valve, it sounds like a good idea, they don't cost much and I can't remember when I changed it last.
Good Luck,
Joe

Hey everyone,

I found a few things since last posting. One, yes you must have all ports closed, obvious I guess, but the vacuum cap i bought has held strong and was only 1.29 for a whole pack. My smell and whole problem stemmed from antifreeze leaking and going into the exhaust as someone mentioned could be possible, and the antifreeze cycling through the vacuum tree makes the hoses and caps soft and slip off. So if yours keep slipping off you may consider checking on that as well.

Good luck thanks for all the input.

Hi JoLEE55,
How and where was the antifreeze getting into the exhaust as you said? And how did you correct the problem?
Thanks,
Joe

:2cents:

there most likely was a plug that fell off - mine did also and I just plugged it


not sure how anti freeze would get into the tree, but be aware that TRANS Fluid can be sucked up into it from a faulty (leaking) vacuum modulator on the transmission. That was what was happening on mine :disappoin
I was slowly burning tranny fluid that was sucked up the vacuum line and the X would backfire and blow off the vacuum lines at the tree (funny now but not at the time). The lines would also slip off because the trans fluid was lubricating them. I replaced the vac mod and nylon tyed the hoses after draining trans fluid from them. worked like a charm :lol2:

just my $.02 worth

Oily hoses are a dead giveaway that the modulator is leaking. As to the smell, I would make sure that the vacuum line to the fuel pressure regulator is still connected. This is located on the fuel rail on the pass side of the engine. With no vacuum line, the fuel pressure increases about 8#. This would be compensated for in some conditions and not others. It would still run fairly well but the exhaust might have a periodic smell. I think devices are:
brake booster
PCV
FPR
tranny vacuum modulator
cruise control
climate control

There are specific ports for different hoses. If you have a Haynes Manual you acn find it on page1-14.
In the front you have to ports, one straight (fuel pressure reg) one bent out (speed control) top side you have one bent out (3/8 power brakes) you have four across the back (CCD, Vac res/EGR, Air cleaner, Auto trans) If you have a five speed one in the back should have a cap. You can use small zip ties to hold the hoses on if you are having issues.

As Fire and Ice mentioned, the cause of the rubber fittings slipping off is because of a small leak in the vacuum modulator on the side of the transmission. Trans fluid is sucked up and most of it is burned off but the rubber fittings get soaked and swell and they slip off really easy or the fly off if the engine "backfires". The fittings and vacuum hoses are not available from Ford. You can make your own by buying the vacuum caps in a package and drill the end of it to receive the small vacuum hoses.
But first replace the vacuum modulator otherwise the problem will come back.

Thanks for the reply, that sounds like some good ideas.
Later,
Joe

I've got a '93 explorer and my vacuum plugs/hoses have come off quite a few times. I keep a package of those little plugs in the car now. Mine seem to be oily, maybe the antifreeze leak problem you talked about earlier. Where is it leaking from, any ideas? And which "modulator" are we talking about? Thanks for any help!

The modulator is on the passenger side of the transmission, just follow the tube. One bolt takes it off, if you can get to it! There is also a little steel dowel pin that will fall out. If you don't want to remove the exhaust, many have done it by removing the seat and going through an access panel. Lot of work for a $12 part. Have you noticed loss of transmission fluid? You could verify the leak by putting in one of those clear inline gas filters like they have for lawnmowers up at the vacuum tree. If filter turns pink, you know for sure.