Leaking Injector - Injector or O-ring?

[87MJJeep]

I smelled gas during my last ride, and popped the hood to find a fuel leak at the front injector.  I could see some fuel between the injector body and the opening in the intake, but the fact so much of the injector was wet makes me question where the leak really is.    

 

It was a cold day and I noticed upon restart it did not get wet again.  That made me think it was the o-ring.

 

With the age of the truck, I am wondering even it if it just an o-ring, should I upgrade to new injectors.  It would be wise to replace all 6 o-rings, so while I am that far into it, go all the way.  I saw the link below during my search:

 

https://www.ksuspensionfab.com/store/p8/Remanufactured%3A_4_Port_Upgraded_Fuel_Injectors_XJ%2FMJ.html#/

 

If I get new injectors, that is in the running, though I saw a comment that cummins93 "does 'em right."  Is cummins93 the person behind ksuspensionfab, or is he another source for injectors?  

 

Thank you for the advice.

Brent

 

 

[Ωhm]

Check that hose for the Fuel Pump Pressure Regulator for fuel. Sure is close enough.

[89 MJ]

If you are going through the work to change the injector O-Rings, and yours are OEM, you should upgrade to 4 hole injectors. They usually come with O-Rings and are ready to install. Make sure you use some assembly grease (like you would use when building an engine) when you put them back together to reduce the chances of pinching an O-Ring and helping to ensure that it will seal up correctly.

[BeatCJ]

35 minutes ago, 87MJJeep said:

https://www.ksuspensionfab.com/store/p8/Remanufactured%3A_4_Port_Upgraded_Fuel_Injectors_XJ%2FMJ.html#/

 

If I get new injectors, that is in the running, though I saw a comment that cummins93 "does 'em right."  Is cummins93 the person behind ksuspensionfab, or is he another source for injectors?  

I can't tell you if Cummins93 and KSuspension are the same place. I have purchased from K Suspension, the product I purchased was well made, their customer service was pretty good and the price was reasonable.

 

I did replace my original injectors with some 4 hole injectors from Ebay. It worked out OK, but I need another set for my son's Cherokee, so I have private messaged @Cummins93. I will feel better about spending my money that a member that is well thought of here has vouched for.

 

I had some fuel leaks from my injectors, I am pretty sure my truck sat for several years with a dead fuel pump. I had gotten it running. Replacing the original injectors did give me a smoother idle, and anecdotally, I think it may have improved power. I had not checked fuel mileage, but I wouldn't be surprised that in a like driving situation, that would improve, too.

[89 MJ]

I (actually my mother) ordered a headlight relay harness for my MJ from KSuspension for my Christmas present. She said that the customer service was fantastic. That didn't answer your question, but if you aren't sure if you should buy from them, I'd recommend them.

[MJCARENA]

I have had good luck from Precision Auto Injectors. They are rebuilt units. Put them in my 1989 wagoneer, 1988 Comanche, and my 1995 F150.

Did the upgraded ones. Just ordered some for my 2000 Durango.

The older factory ones on my Wagoneer leaked at the body of the injector.

[87MJJeep]

48 minutes ago, MJCARENA said:

I have had good luck from Precision Auto Injectors. They are rebuilt units. Put them in my 1989 wagoneer, 1988 Comanche, and my 1995 F150.

Did the upgraded ones. Just ordered some for my 2000 Durango.

The older factory ones on my Wagoneer leaked at the body of the injector.

 

Thanks!  That confirms the body can leak.

  

2 hours ago, 89 MJ said:

If you are going through the work to change the injector O-Rings, and yours are OEM, you should upgrade to 4 hole injectors. They usually come with O-Rings and are ready to install. Make sure you use some assembly grease (like you would use when building an engine) when you put them back together to reduce the chances of pinching an O-Ring and helping to ensure that it will seal up correctly.

 

Thanks for the feedback.  I would not have known to use any grease.  Is any other type of grease OK to use?  (never used any for engine building)

 

2 hours ago, Ωhm said:

Check that hose for the Fuel Pump Pressure Regulator for fuel. Sure is close enough.

 

 

Thanks!

 

 

[87MJJeep]

1 hour ago, BeatCJ said:

I can't tell you if Cummins93 and KSuspension are the same place. I have purchased from K Suspension, the product I purchased was well made, their customer service was pretty good and the price was reasonable.

 

I did replace my original injectors with some 4 hole injectors from Ebay. It worked out OK, but I need another set for my son's Cherokee, so I have private messaged @Cummins93. I will feel better about spending my money that a member that is well thought of here has vouched for.

 

I had some fuel leaks from my injectors, I am pretty sure my truck sat for several years with a dead fuel pump. I had gotten it running. Replacing the original injectors did give me a smoother idle, and anecdotally, I think it may have improved power. I had not checked fuel mileage, but I wouldn't be surprised that in a like driving situation, that would improve, too.

 

Thank you for the comments!

[89 MJ]

14 minutes ago, 87MJJeep said:

Thanks for the feedback.  I would not have known to use any grease.  Is any other type of grease OK to use?  (never used any for engine building)

 

That I do not know.

[PhilisDiller]

I just used Vaseline when re-installing the injectors with new orings. I can tell you they WILL bind and pinch/tear if you don’t use something like Vaseline. I’d also recommend just getting a set of injectors that come with the rings. You’ll pay $10-$15 for just the orings alone. 

[87MJJeep]

I just used Vaseline when re-installing the injectors with new orings. I can tell you they WILL bind and pinch/tear if you don’t use something like Vaseline. I’d also recommend just getting a set of injectors that come with the rings. You’ll pay $10-$15 for just the orings alone. 

Thank you!

Sent from my SM-N975U using Tapatalk

[PhilisDiller]

If you end up just doing the o-rings withou new injectors, make sure you save a couple of your old o-rings just in-case one of the new ones tear on the way in. They only give you 12 o-rings and if ones messed up, you're SOL. I found them to be very difficult to fit back into the fuel rail, but with vaseline and a LITTLE bit of wiggling, they will go in. If you wiggle at too much of an angle, the o-ring will bind and get ruined... don't ask me how I know

[BeatCJ]

I second Vaseline, or any other petroleum jelly. They do make special o-ring lube, but I don't know that it's of value for this application.

[87MJJeep]

46 minutes ago, PhilisDiller said:

If you end up just doing the o-rings withou new injectors, make sure you save a couple of your old o-rings just in-case one of the new ones tear on the way in. They only give you 12 o-rings and if ones messed up, you're SOL. I found them to be very difficult to fit back into the fuel rail, but with vaseline and a LITTLE bit of wiggling, they will go in. If you wiggle at too much of an angle, the o-ring will bind and get ruined... don't ask me how I know

 

I appreciate the heads up.  I can imagine how easily they are torn.  

 

I just fired it up, and no leak.  Took it for a drive and still no leak.  55 degrees today vs ~30 degrees the other day when it leaked.  That was the coldest start up it's had in a long time.  

 

I can see a spot on the side of the injector.  It looks like a wet spot in the photo, but it's totally dry.  I have to wonder if the cold day leak was at one of the seams in the side of the body, and that spot was "washed" by the fuel.  

 

Leaning toward getting a set of 4 hole injectors and be done with it. 

 

7 minutes ago, BeatCJ said:

I second Vaseline, or any other petroleum jelly. They do make special o-ring lube, but I don't know that it's of value for this application.

 

Good to know!