Missing vacuum line? Help me find it please!

[pachakutek]

So my truck started idling weird last night. While stopped and gear on P the tach will oscillate a bit, but as soon as put into gear D it would go crazy.... the engine will rev up and down 400-800 RPM, almost killing the engine sometimes....

At first I thought that it had to do with something electrical (coil), since I recently installed a remote start system on it (see my DIY link at the end)... but it was nothing of that sort....

Today with sunlight I took a look,and found out the cause.... I noticed a loud hissing that was coming from the open nipple in the pic (I have mi finger blocking it)... As soon as I blocked the vacuum leak the car started to idle normally... I have temporally "fixed it" with a plug (made out of a napkin )

There was obviously a vacuum line there before, but I cannot seem to find it (I looked)... can somebody help me out (look at your car) and tell me where/what the line should be... what does it connect to? where is the other end? (Pics will be great too)

Thanks!
Tona

PS:
Check out my remote starter DIY HowTo

 

[mikeinri]

Um, you have two lines circled. Which one are you missing?

Mike

 

[pachakutek]

you see the metallic nipple that I'm blocking with my finger (inside the circle a shiny thing).... there needs to be something there missing, but I cannot find what.... Can someone please take a look at their car? (pic pls

Here is another picture with the paper-plug fix... (the open vacuum nipple is the shiny thing with the piece of paper.... but I need to find what was there before)

 

[pachakutek]

Um, you have two lines circled. Which one are you missing?

Mike

ohh... not those 2 thick lines, those are fine.... behind them (in between them) there is the shiny nipple my finger is blocking.

I suppose there was a vacuum line on that nipple, but I cannot find it.... Thanks

 

[Maniak]

I see 6 vacuum lines there.. That is all there should be on a '92.. IIRC 3 are hard lines (hard plastic), two are large (Brakes and Cruise) and then another line for the Automatic Trans.. The extra(s) are just capped..

In 1993 (CA model) and 1994 there is also a hose for the EGR.

~Mark

 

[pachakutek]

Thanks for all the input... but I think I wasn't clear... here a zoomed in pic... hopefully that makes sense now:

I need to find the line that goes on that nipple.... If someone pls tell me where the line that goes on that nipple connects to, I can possibly look for the other end of that line and track it/reconnect it.

 

[Maniak]

We are on the same page.. Under the word "for" is a vacuum line and it appears to be connected (the only one I wasn't sure about).. if it is.. you have all the lines connected. What you are missing is a vacuum cap. Most parts stores sell them.. My guess is it got brittle over time and just fell off.

~Mark

 

[pachakutek]

ohhh.. ok, so you think that there was no line there connected at the nipple ever.... just a cap that fell off? Can someone confirm? (check in their car please, and post here, Thanks!)

I'll double check that line under "for" you mention, but I think all the lines that are pictured (visible) are connected.....

 

[Shen2187]

Yeah it's a line for manual transmission (they use the same block in rangers if my information is correct) and since yours is auto, it's capped off. I had the same thing happen to mine when I got it. The cap eventually rotted enough to fall off so I just took some fuel line stuck it on the nipple and screwed a screw in the end of the fuel line.

Or you could buy a new cap, mine fell off on a trail so I just did the fuel line instead... And because I'm cheap

 

[fixxxer]

X2 You can either make or buy a cap for that vacuum nipple, I checked my '93 Ex w/Auto and there is just a rubber boot to seal that port.

 

[pachakutek]

Thank you guys for helping out solving "The mystery of the missing vacuum line" ... there was no "missing vacuum line" after all.... no wonder I couldn't find it.

I'll cap it off then and forget about it!

Thanks a bunch!

 

[fixxxer]

Since the original seal-plug was old enough to come off/fall off that vacuum tree, you might want to check the other hoses there. The rubber will crack, dry out and rot with age, heat and gas fumes. A little preventive maint. now may save you from a breakdown a little ways down the road.

 

[mikeinri]

Sorry I didn't see that the first time (forest for the trees, so to speak)...

fixxxer beat me to it, you should be looking to replace all the fittings that you can, elbows, plugs, etc. Usually when one goes, the rest aren't far behind.

Also, this would be a good time to be sure there is no ATF in any of those lines. If there is, you need to replace the vacuum modulator on the tranny. Not saying yours is definitely bad, but it's really common, and that's usually the main clue. Do a search here if you need more info on that.

Hope this helps.

Mike

 

[mkilday21]

I do have three line back there two go across to the passenger side and one loops underneath the tree and joins to a double boot with another smaller line going up from there

 

[mkilday21]

But I am missing the hard line in front of the tree can anyone tell me where that goes I have it plugged now 94 explorer 4x4

 

[mkilday21]

missing hard vacuum line on front of tree

All of my vacuum lines are wet and kept popping off but only on the back now I am missing the booted hard plastic line on the front of the tree I have it plugged and the? truck is running fine but I don't think this could be good