Vacuum Elbow

[XJ Wheeler]

Hey guys, quick dilemma.

Short while back when i was replacing my radiator i noticed the elbow on the vacuum line at the fuel rail coming from the intake was very rotted and cracked. I removed it and got a set of various elbows from the parts store. Replaced it and after being driven i noticed the new one was melted and deformed beyond use. Replaced that one with a new thicker one but after going up to Matts the other day this one as well melted and created a hole. Is there a special elbow i should be using or something?

1275

[LizardRunner]

I would get a new one and wrap it in heat shield foil, I've done that to mine on both the green lizard and now the red lizard. There are several types of this stuff, one is cheep (aluminum duct sealing tape, several wraps of it works pretty well) and a thicker true Heat shield that is sticky backed. http://paceperformance.com/c-152247-pace-super-stores-heatshield-products-heatshield-tape-and-fasteners.html

[xj4life2]

Tap it and use a metal one, but for the life of me I cant figure out why its getting hot enough to melt the normal ones ?????

[prerunner1982]

Just proves how hot it can get under the hood of an XJ.

And seeing as how he said "various ones from the parts store", I would be inclined to believe they aren't the same material/strength as the stock unit.

Maybe hit the junkyard for a factory one in decent condition?

[xj4life2]

Upon further review and discussion with my master tech, You either have an exhaust leask at the #1 runner which is right there or your running way to lean causeing an extreamly high exhaust temp. No XJ should be hot enough at a vac line to melt plastic. Hope this helps

[ParadiseXJ]

Do you have an aluminum heat shield on the manifold??

[XJ Wheeler]

No on the heat shield, i don't think it came with it. My brothers '90 has one but not mine. :confused:

I keep coming back to how it didn't melt the original, that's why i think these new ones are just inferior.

[xj4life2]

No on the heat shield, i don't think it came with it. My brothers '90 has one but not mine. :confused:

I keep coming back to how it didn't melt the original, that's why i think these new ones are just inferior.

read post #5 , check into those two , pretty sure one of them is the culprit

[Comanche91]

You can always convert to the 1999+ intake and use the dealer supplied heat shield like I did. Keeps the fuel rail a lot cooler. It was a TB to help prevent heat soak.

http://i182.photobucket.com/albums/x297/comanche91/HeatShield-1.jpg

[cpttuna]

If that heat shield is only $3.oo, it might pay to pick up an extra one: no telling where you might be able to use a piece of that somewhere else on the XJ.

[Comanche91]

I did. :D

[XJ Wheeler]

read post #5 , check into those two , pretty sure one of them is the culprit

I did read it. I'll check for the leak and what's the best way to check for it running lean?


You can always convert to the 1999+ intake and use the dealer supplied heat shield like I did. Keeps the fuel rail a lot cooler. It was a TB to help prevent heat soak.

http://i182.photobucket.com/albums/x297/comanche91/HeatShield-1.jpg
I like this idea. :D I actually do plan on getting one of those intakes, just down the line a little.

[ParadiseXJ]

My MJ did not have the shield, my XJ did.

The split loom wiring casing was melting along the head/valve cover of the MJ. Snagged one at the junkyard of a 4.0L for $2. I don't mean the quilted heat shield bought at AZone...just the one that bolts on all along the length of the manifold (bolts TO the manifold) under the fuel rail. Catches spills, leaks from the top and channels heat from below.

[XJ Wheeler]

My MJ did not have the shield, my XJ did.

The split loom wiring casing was melting along the head/valve cover of the MJ. Snagged one at the junkyard of a 4.0L for $2. I don't mean the quilted heat shield bought at AZone...just the one that bolts on all along the length of the manifold (bolts TO the manifold) under the fuel rail. Catches spills, leaks from the top and channels heat from below.

Yeah, my brothers '90 XJ has one. I just rarely get time to go to the jy.

[xj4life2]

[QUOTE=XJ Wheeler;139796]I did read it. I'll check for the leak and what's the best way to check for it running lean?


With out a gas analyzer (smog machine) its tough. Have you checked for codes ? Probably where I would start , then check TPS and IAC for cleanliness and proper adjustment. If you havent changed the o2 in a while that would be a good move also. As per Jeep they should be changed every 28K , strange number I know but it is what it is.

[XJ Wheeler]

I figure a month is long enough to post up my solution. :rolleyes:

I ended up getting some original type elbows from another member (Blaze) who was parting out a XJ. That did the job. So, for everyone to know. The auto parts vacuum elbow are junk. Their too thin and collapse, and can't handle the heat. The "new" ones are much thicker and harder rubber.

Btw, i checked the codes too. Only a previous battery disconnected code.

[cpttuna]

after mentionbing the idea, I purchased 4 myself. I believe they were $2.75 each.

[XJScarlet]

I had to replace the same elbow. I bought a mixed pack from AZone and have had no problems with it melting. However, I have redone my cooling system and my jeep rarely runs hot.

[XJ Wheeler]

I had to replace the same elbow. I bought a mixed pack from AZone and have had no problems with it melting. However, I have redone my cooling system and my jeep rarely runs hot.

I just replaced my radiator, thermostat, and hoses too. Mine is running around 160° now (probably need to change that), but i don't see it being a problem.

[Carves]

I just replaced my radiator, thermostat, and hoses too. Mine is running around 160° now (probably need to change that), but i don't see it being a problem.



ohhhh dear lord ... an XJ running at less than 210* :eek::eek:


.... you'll be swamping the cylinders with petrol, getting 2mpg, killing fluffy animals with exhaust gases ... and all sorts of things .. :rolleyes: .. :smiley-laughing021:


Probably want to do something about it ;)

At 160* you've only just cleared what the later model OBDII manual calls a "warm-up cycle" temp.

... So its likely your running in the lowest - of any "warmed cycle" fuel settings
... and in the longterm, will probably also, get some moisture build up in the engine.


PCM type regardless ... You will be better off getting the temp back up in the 190*/200* vicinity.

[XJ Wheeler]

ohhhh dear lord ... an XJ running at less than 210* :eek::eek:


.... you'll be swamping the cylinders with petrol, getting 2mpg, killing fluffy animals with exhaust gases ... and all sorts of things .. :rolleyes: .. :smiley-laughing021:


Probably want to do something about it ;)

At 160* you've only just cleared what the later model OBDII manual calls a "warm-up cycle" temp.

... So its likely your running in the lowest - of any "warmed cycle" fuel settings
... and in the longterm, will probably also, get some moisture build up in the engine.


PCM type regardless ... You will be better off getting the temp back up in the 190*/200* vicinity.

Lol, yep. :D

I don't really get it though, has a 180° thermostat in there. I guess i'll swap it with a 195° and see. Just glad its not overheating anymore, and hope touching it doesn't set it off again. :rolleyes:

[XJScarlet]

:rolleye0012:

Mine runs at about 160 too......
Looks like I might swap that thermostat.