Leaking Injector Fixes Itself

I had a gas smell the other day, noticed the front injector leaking from where it meets the head. It was very wet with fuel, with a small spray emerging. Suspected the O-rings, so I got a $10 set. I went to change them all today after driving it a bit, and when I popped the hood, no gas smell, and no evidence of fuel leak. Checked it while running, and no fumes, or fuel spray as before. So, I left it as is, and will change the O-rings only if I have the problem again. What could have caused this temporary injector leak? Anyone have a similar experence?

when you noticed the injector leak, did you move the injector around at all?? if you twisted it some, you may have moved it just enough to seal back up.... If you already have the new o-rings, you're better off just changing them at you're earliest convenience, why wait till it leaks again?? by then you could have one crispy XJ!

Don't trust it - change it! Also, if you have a Renix XJ (87-90 4.0) plan on a new set of injectors, as they are known for leaking at the body seam - where the metal and plastic meet.

Doing the orings really isn't that difficult, it takes about half an hour (an hour if you are figuring it out as you go.) Tips...

1) Soak the new orings in a small cupful of gasoline while you tear everything down. This softens them and reduces the possiblity of "skinning" them on installation.

2) Check the bungs in the intake for debris when you remove the injectors. A 12gage or 16gage shotgun bore brush (bronze) works quite well for cleaning the bores.

3) A small amount of assembly grease works wonders when slipping the injectors in place.

4) Remove the entire fuel rail as an assembly. It really is easier that way.

5) Change the quick-connector seals while you are in there. They're as old as the injector orings, and just as prone to failure.

That's it off the top of my head. I'm sure there's more, and someone will sound off (I hope!) with the bits I missed...

5-90

Second opinions are great but I gotta give ya the same answer ya got on JU...

Either change the o-rings / swap out the leaky injectors or buy a bag of marshmallows and a fire extinguisher.

Click to expand...

C'mon! FIX the dang thing! It's an easy job! This isn't something to fool around with, especially for no more than it'll take to fix it and what can happen if ya don't!

O-rings are cheap. ($11)
(6) eBay injectors are cheap. ($40)
Your XJ catching on FIRE is expensive. (Can you replace your XJ for less than the cost of some o-rings or injectors?)

Seriously, FIX it.


Heat changes clearances as things expand / contract thus the leak can come & go... wanna know what happens when the leak decides to come back on a hot engine & gas hits the exhaust downpipe?

i had one injector that would only leak when it was cold outside. i even changed the o-rings last spring and it didn't leak all summer long, but when it started getting colder i could smell the gasoline again. just changed the entire injector a few weeks ago and no more leaks...

The Renix injectors will also sometimes leak intermittently around the rubber grommet at the electrical connection. You should check for this too, and unless you have a serious doubt whether your Jeep as a whole is worth more than a set of new injectors (a possibility that does sometimes exist), consider getting a whole new set.