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still leaking fuel after new o rings gremlins i think

M

mramr1974

NAXJA Forum User
Location
idaho
1993 xj 4.0 auto 4x4,
Fuel was leaking so i replaced the o rings and fixed the leak , Then I dont start it for a day and new leaks when i start it back up the next day so i clean the intake side it was filthy duh i didnt know i had to, ok so after i cleaned all the intake holes i reinstalled the injectors and fired it up and number 1 injector leaking out the body so i swaped it out and fired it back up and let it run for 45 minutes with no leaks.
Today i fired it up after sittin 2 days 4 injectors leaking at bottom o rings and what looks to be the body or possible rail side o ring but the injector I swaped looks great no leaks.
I didnt soak the o rings in gas before install or use vasiline on rail side i did however use a good soaking of wd-40.
The main thing i want to know is anyone ever ran into this no leak one day and big leak next day crap it doesent make sense ill probaly be swapping all the injectors from a doaner I have and put a new set of o rings in to.
Very frustrated here possible fuel regulator issue any advice would be great
 
are they the original injectors?

i did recently switched mine out (1993 like yours) to the ford 5.0 injectors (pulled from JY), and when i installed mine i used plenty of vasoline. no leaks.

vasoline should do it.
 
i have seen 2 piece injectors leak one day that not at all the next.....being thats the way they are i would Pitch them in the trash...not worth the risk of a fire.

For you i would swap in some Ford 5.0 Explorer "stick" orange Injectors and a High pressure FPR and be done with it.
 
hightime81 said:
are they the original injectors?

i did recently switched mine out (1993 like yours) to the ford 5.0 injectors (pulled from JY), and when i installed mine i used plenty of vasoline. no leaks.

vasoline should do it.
Click to expand...
you should be running a High pressure FPR with those also.
 
98 jeepjeep said:
you should be running a High pressure FPR with those also.
Click to expand...

A**uming FPR stands for Fuel Pressure Regulator, then I must ask what you are talking about?

The Ford (Bosch) orange-top injectors are 19 lbs injectors, stock are 18.6 lb. The injectors are not going to change the pressure of the system--31 psi with vacuum applied to the stock fuel pressure regulator mounted on the fuel rail, and 39 psi without vacuum applied.

So, what "High pressure FPR" are you talking about, again, a**uming "FPR" is short for "Fuel Pressure Regulator"?
 
mramr1974 said:
1993 xj 4.0 auto 4x4,
Fuel was leaking so i replaced the o rings and fixed the leak , Then I dont start it for a day and new leaks when i start it back up the next day so i clean the intake side it was filthy duh i didnt know i had to, ok so after i cleaned all the intake holes i reinstalled the injectors and fired it up and number 1 injector leaking out the body so i swaped it out and fired it back up and let it run for 45 minutes with no leaks.
Today i fired it up after sittin 2 days 4 injectors leaking at bottom o rings and what looks to be the body or possible rail side o ring but the injector I swaped looks great no leaks.
I didnt soak the o rings in gas before install or use vasiline on rail side i did however use a good soaking of wd-40.
The main thing i want to know is anyone ever ran into this no leak one day and big leak next day crap it doesent make sense ill probaly be swapping all the injectors from a doaner I have and put a new set of o rings in to.
Very frustrated here possible fuel regulator issue any advice would be great
Click to expand...

Time to wake up and smell the ethanol!

Do yourself a favor and get rid of ALL two-piece body OEM style injectors. They are XJ BBQ starters.

Go to the parts store and blow $300 bucks on a set of newer style injectors, or hit the salvage yard and pay about $30 for a set for Ford (Bosch) orange-top 19 lb injectors--single piece body, 4-hole nozzle instead of a single, use Ford o-rings, direct fit plug-in common sense upgrade.

Also, use an appropriate caliber/gauge cleaning brush to clean the openings in the fuel rail and intake before installing the new injectors, and put a light coat of petroleum jelly on the o-rings or soak them in some fuel prior to installation.
 
joe_peters said:
A**uming FPR stands for Fuel Pressure Regulator, then I must ask what you are talking about?

The Ford (Bosch) orange-top injectors are 19 lbs injectors, stock are 18.6 lb. The injectors are not going to change the pressure of the system--31 psi with vacuum applied to the stock fuel pressure regulator mounted on the fuel rail, and 39 psi without vacuum applied.

So, what "High pressure FPR" are you talking about, again, a**uming "FPR" is short for "Fuel Pressure Regulator"?
Click to expand...
Your 1990 Renix is equipped with (Factory) 19LB/240CC Injectors at 39PSI However the Ford 19LB yellow Injectors you swapped in are 19lb/210CC at 39PSI. In order to fill that gap you need to Install a High pressure FPR to bring to Pressure up to 96+ HO standard which is 49psi Constant. I have a list of OEM Mopar cars that had the regulator you need and also a site that sells adjustable ones...but they are expensive. There is alot more to Injector flow than LB.......
 
98 jeepjeep said:
Your 1990 Renix is equipped with (Factory) 19LB/240CC Injectors at 39PSI However the Ford 19LB yellow Injectors you swapped in are 19lb/210CC at 39PSI. In order to fill that gap you need to Install a High pressure FPR to bring to Pressure up to 96+ HO standard which is 49psi Constant. I have a list of OEM Mopar cars that had the regulator you need and also a site that sells adjustable ones...but they are expensive. There is alot more to Injector flow than LB.......
Click to expand...

OP is driving a 1993 with the same fuel specs as a Renix and the Ford injectors work fine, no need to fill any "gap".
 
Sure there is...210CC Isnt 240CC. the Ford 19LB/210CC injectors work best at higher pressure...you could run the risk of going lean at higher throttle..not to mention that the Ford Injectors will be ran at a higher Duty Cycle. Your other option is Neon 2.4L Injectors which require No upgraded Regulator ON PRE 96. And actually Renix 87-90 will need to swap to a 91-95 Fuel rail to use the Regulator.
 
Last edited:
For all us lurkers and learners could someone post pictures of the two piece injectors that are the bad ones? Markings? Colors?

--Thanks in advance--
 
orange said:
For all us lurkers and learners could someone post pictures of the two piece injectors that are the bad ones? Markings? Colors?

--Thanks in advance--
Click to expand...

No pix, but they're pretty easy to spot.

The earlier "two-piece" injectors have a metal lower shell and a plastic upper shell, and are crimped together (this is why they start leaking - expansion & contraction of the metal lower shell due to heat cycles, resulting in failure of the crimp joint.)

Later "one-piece" injectors - and replacements - are still technically a two-piece housing, but both parts are of similar plastic and they're ultrasonically welded together after the injector is "stuffed." Being similar material, you don't have the differential expansion problem. Being welded vice crimped, you don't have a "loose" joint to worry about.
 
I'm getting confused. I got my Mustang injectors this week and was going to swap them in tomorrow. Why do I need a different fuel pressure regulator?? As long as the flow rate and operating pressures are pretty close I'd be ok, correct? Also I was planning to wiggle the rail enough to pull the injectors out without disconnecting the feed & return lines. What's the best way to clean the rail?
 
If you search, you will find numerous XJs are running the 19 lb injectors w/o changing the regulator, but that was good information posted and something to chew on.

To change the injectors:

Release any pressure in the fuel rail--push in the Schrader valve.

Unplug the injector harness--I usually use the "dice" method and mark the connectors with a gray sharpie--one dot for cyl 1, two dots for cyl 2, and so on. Not a great chance of mixing them up, and I'm a bit annal retentive (some of my closest friends just call me annal for short).

Remove the bolts holding the rail to the intake. I also lifted the vacuum harness where the front and rear pieces join, and removed the bracket nut.

Use a large screwdriver or pry bar to leverage the injectors while you gently pull on the fuel rail. You should be able to get the rail up with all of the injectors still in it.

Remove the clips, and pull the injectors one at a time. Check each injector as you remove it--did both seals come out with it?

Once you have all of the injectors out, you can clean the fuel rail and intake with a shotgun bore brush. A .410 should do it.

Install the new injectors, using a thin coat of petroleum jelly on the top and bottom o-rings. Insert all of the new injectors into the rail, securing each one with its clip.

Position the rail and the injectors so that you can align the injector nozzles with the intake ports. Carefully push the rail down, adjusting the injectors as necessary.

Replace all the stuff you took off, bolts, nut, vacuum harness, injector harness.

Enjoy.
 
1987Comanche said:
I'm getting confused. I got my Mustang injectors this week and was going to swap them in tomorrow. Why do I need a different fuel pressure regulator?? As long as the flow rate and operating pressures are pretty close I'd be ok, correct? Also I was planning to wiggle the rail enough to pull the injectors out without disconnecting the feed & return lines. What's the best way to clean the rail?
Click to expand...
I dont know why Everyone wants to get the Fat body Mustang Injectors...they only spray from 1 Pintle...

It the yellow "stick" style injectors you want..they are found on 5.0Explorers and most 4.6L Ford vehicles the Bosch # is 0280155710. Your 88 Runs at 39psi base...that simply isnt enough pressure for these injectors...you need to run at 49psi. Or simply Swap in a set of Neon 2.4L injectors with no Changes.........
 
98 jeepjeep said:
I dont know why Everyone wants to get the Fat body Mustang Injectors...they only spray from 1 Pintle...

It the yellow "stick" style injectors you want..they are found on 5.0Explorers and most 4.6L Ford vehicles the Bosch # is 0280155710. Your 88 Runs at 39psi base...that simply isnt enough pressure for these injectors...you need to run at 49psi. Or simply Swap in a set of Neon 2.4L injectors with no Changes.........
Click to expand...

Wrong.
 
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