Another Vacuum Question
Thread Starter
Junior Member
Joined: Jul 2011
Posts: 59
Likes: 0
From: Brentwood, CA
Year: 1988
Model: Cherokee
Engine: 4.0L
Hello,
I replaced the vacuum harness and I'm still having a vacuum leak. I believe I've found the culprit, the vacuum tube that runs from the throttle body to the map sensor. If I spray throttle body cleaner on it where it joins the throttle body, the engine revs up. Does anyone know where to find that part? It's for an 88 XJ, and I haven't been able to find the part. Here is a pic:
https://i.imgur.com/dTjrT.jpg
Also, I found this while tracing out vacuum lines:
https://i.imgur.com/xytTf.jpg
Does that plastic plug look legit? It seems pretty custom to me.
Is it something I should be concerned about?
Thanks again!
I replaced the vacuum harness and I'm still having a vacuum leak. I believe I've found the culprit, the vacuum tube that runs from the throttle body to the map sensor. If I spray throttle body cleaner on it where it joins the throttle body, the engine revs up. Does anyone know where to find that part? It's for an 88 XJ, and I haven't been able to find the part. Here is a pic:
https://i.imgur.com/dTjrT.jpg
Also, I found this while tracing out vacuum lines:
https://i.imgur.com/xytTf.jpg
Does that plastic plug look legit? It seems pretty custom to me.
Is it something I should be concerned about?Thanks again!
CF Veteran
Joined: Oct 2009
Posts: 2,867
Likes: 16
From: Fauquier County, Virginia
Year: 1991
Model: Cherokee
Engine: I-6 4.0 HO
Hello,
I replaced the vacuum harness and I'm still having a vacuum leak. I believe I've found the culprit, the vacuum tube that runs from the throttle body to the map sensor. If I spray throttle body cleaner on it where it joins the throttle body, the engine revs up. Does anyone know where to find that part? It's for an 88 XJ, and I haven't been able to find the part. Here is a pic:
https://i.imgur.com/dTjrT.jpg
Also, I found this while tracing out vacuum lines:
https://i.imgur.com/xytTf.jpg
Does that plastic plug look legit? It seems pretty custom to me.
Is it something I should be concerned about?
Thanks again!
I replaced the vacuum harness and I'm still having a vacuum leak. I believe I've found the culprit, the vacuum tube that runs from the throttle body to the map sensor. If I spray throttle body cleaner on it where it joins the throttle body, the engine revs up. Does anyone know where to find that part? It's for an 88 XJ, and I haven't been able to find the part. Here is a pic:
https://i.imgur.com/dTjrT.jpg
Also, I found this while tracing out vacuum lines:
https://i.imgur.com/xytTf.jpg
Does that plastic plug look legit? It seems pretty custom to me.
Is it something I should be concerned about?Thanks again!
Edit: Got bored and looked for you lol.
Here's the entire harness if you have old brittle hoses:
http://www.teamgrandwagoneer.com/par...iled/3001.html
As for the MAP sensor hose specifically, I didn't see it. However, I may have missed. Try gettin in contact with them about what you need... I'd bet they have it somewhere lol.
parts@teamcherokee.com
Hope this helps!
CF Veteran
Joined: Mar 2010
Posts: 47,923
Likes: 38
From: Broward County Fl.
Year: 1989 xj sport 2dr
Model: Cherokee
Engine: 12 hole bosch Injectors
the vacuum for the map sensor can come from any vacuum port if its the grommet leaking plug the hole in throttle body and tap into a nother constant vacuum source...
CF Veteran
Joined: Mar 2010
Posts: 47,923
Likes: 38
From: Broward County Fl.
Year: 1989 xj sport 2dr
Model: Cherokee
Engine: 12 hole bosch Injectors
Trending Topics
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
Likes: 1,578
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
I just called Napa and they only show the harnesses, a front and rear.
Freegdr is correct. You could use any manifold vacuum source. The issue is gonna be plugging the hole in the throttle body.
Is the harness plugged into the correct hole in the throttle body?
Freegdr is correct. You could use any manifold vacuum source. The issue is gonna be plugging the hole in the throttle body.
Is the harness plugged into the correct hole in the throttle body?
Thread Starter
Junior Member
Joined: Jul 2011
Posts: 59
Likes: 0
From: Brentwood, CA
Year: 1988
Model: Cherokee
Engine: 4.0L
Yeah, I got the harness from Napa already, that's how I got into this mess.
It only plugs in one way. If you look at the picture, that black grommet is a single piece of rubber. As far as I can tell, the top nipple is just there for stabilization. There was nothing plugged into it when I started this affair, and if I put my finger over it, there is no suction, or change in RPM. I think the problem is that the grommet is old and sits in there loosely. I saw a few other threads from Renix engine owners and they said that their's was the same way. Although if any of you have information to the contrary, feel free to let me know. I guess I'll just have to pony up the 30 bucks to get the right part shipped to me. $12 for shipping for a 2 ounce part is just ridiculous! Oh well. Thanks for all the help guys!
It only plugs in one way. If you look at the picture, that black grommet is a single piece of rubber. As far as I can tell, the top nipple is just there for stabilization. There was nothing plugged into it when I started this affair, and if I put my finger over it, there is no suction, or change in RPM. I think the problem is that the grommet is old and sits in there loosely. I saw a few other threads from Renix engine owners and they said that their's was the same way. Although if any of you have information to the contrary, feel free to let me know. I guess I'll just have to pony up the 30 bucks to get the right part shipped to me. $12 for shipping for a 2 ounce part is just ridiculous! Oh well. Thanks for all the help guys!
Senior Member
Joined: Jun 2009
Posts: 553
Likes: 1
From: West Texas
Year: 1991
Model: Cherokee
Engine: 4.0 L

Wongfat.......this is gonna sound crazy, and 'lafffa while you a can..a monkee boy!" (ha whats that from? 10 beers you get it right!)
Anyway.....that thin piece o crap plastic tube you took out and replaced with the kit you bought? Hope you kept it?
Here is what I did with the split and broke in half flimsy crap tube....
first i put super glue to the two broke pieces put together as close as possible so they meld close.. waited 20 minutes. then I used black rtv all around that joint, waited about 20 minutes again, then put electrical tape around the wound. as for the split, I put black rtv along the slit, then taped it over with electrical tape...
as for the funky cracked rubber elbow which the chinsy plastic tube goes into, I used the same black RTV all over it and let it dry.
the whole assembly I let dry for 24 hours then put it on the jeep and it has been running great, NO leakee!!!
again, my opinion and what worked for me.
good luck sir!
cpnwrench
Thread Starter
Junior Member
Joined: Jul 2011
Posts: 59
Likes: 0
From: Brentwood, CA
Year: 1988
Model: Cherokee
Engine: 4.0L
I was actually thinking about using RTV to make the seal. At 30 bucks, I think that may be the way to go. Just put some RTV around the grommet, stick it in there and let it cure. I just need to go lightly enough so that none of it makes it into the throttle body itself. I got nothing on the quote, sorry!
Senior Member
Joined: Jun 2009
Posts: 553
Likes: 1
From: West Texas
Year: 1991
Model: Cherokee
Engine: 4.0 L

Quote is from..........
wait for it......
Buckaroo Bonsai Across the 8th Dimension...
Bada$$ Ford F250 goin through a mountain is the awesomest!
cpnwrench
Senior Member
Joined: Aug 2011
Posts: 760
Likes: 6
From: Landers, CA
Year: Several
Model: Cherokee
Engine: 4.0
That thin plastic tubing is used for as reason. That's a critical vacuum signal to the MAP.
Parts houses have the tubing, just not molded. They also have the rubber bends, elbows etc.
Dealer have the molded hoses.
To repair bad spots, simply cut out thr bad spots and slip a small rubber hose over the break.
The thin plastic doesn't collapse like rubber, and being small subtle changes in vacuum cause an immediate reaction in the MAP. Larger rubber lines act like a big storage tank, slowing reaction time = stumbles etc., plus they collapse causing problems too. Jeep engineers really weren't crazy.
Parts houses have the tubing, just not molded. They also have the rubber bends, elbows etc.
Dealer have the molded hoses.
To repair bad spots, simply cut out thr bad spots and slip a small rubber hose over the break.
The thin plastic doesn't collapse like rubber, and being small subtle changes in vacuum cause an immediate reaction in the MAP. Larger rubber lines act like a big storage tank, slowing reaction time = stumbles etc., plus they collapse causing problems too. Jeep engineers really weren't crazy.
::CF Moderator::
Joined: Aug 2011
Posts: 43,971
Likes: 1,578
From: Prescott, Az
Year: 1990
Model: Cherokee (XJ)
Engine: 4.0

Wongfat.......this is gonna sound crazy, and 'lafffa while you a can..a monkee boy!" (ha whats that from? 10 beers you get it right!)
Anyway.....that thin piece o crap plastic tube you took out and replaced with the kit you bought? Hope you kept it?
Here is what I did with the split and broke in half flimsy crap tube....
first i put super glue to the two broke pieces put together as close as possible so they meld close.. waited 20 minutes. then I used black rtv all around that joint, waited about 20 minutes again, then put electrical tape around the wound. as for the split, I put black rtv along the slit, then taped it over with electrical tape...
as for the funky cracked rubber elbow which the chinsy plastic tube goes into, I used the same black RTV all over it and let it dry.
the whole assembly I let dry for 24 hours then put it on the jeep and it has been running great, NO leakee!!!
again, my opinion and what worked for me.
good luck sir!
cpnwrench

Wongfat's situation is a little different as teh rubber plug going into the throttle body must be deteriorated.



