• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

Leaky Fuel Injectors?

Z

Zoro

NAXJA Forum User
Location
Colorado
Just started smelling gas yesterday so this morning I looked over the entire fuel system and found out that my two forward most fuel injestors are leaking from where they go into the intake manifold.

What causes this? FOD? Anyway to fix/save them or is time for new ones?

Also if I were to put some injectors in that are rated for a higher fuel pressure than stock would this alter the performance of my engine in a bad way?

1990 XJ 4.0 205K
 
I tried all the big name auto suppliers in town and none have o ring kits, IF I were to go to a dealer about how much would I be looking at? How do you pull an injector? Never done this before....

So you had a similar problem and all it took to fix it was some Lucas?
 
I had to replace my injector seals a few months ago. The local oreilly auto parts had them? It is fairly common to replace them, I am surprized your local parts stores don't cary them.
 
Zoro said:
I tried all the big name auto suppliers in town and none have o ring kits, IF I were to go to a dealer about how much would I be looking at? How do you pull an injector? Never done this before....

So you had a similar problem and all it took to fix it was some Lucas?
Click to expand...

RENIX fuel injectors are known for leaking - don't take chances.

The O-ring kit at the dealership goes for about $15 out here, and comes with 13 o-rings (two for each injector, one for the regulator.) They're two different coluors - I don't recall which one goes where offhand, but the colour with the extra ring goes on top.

Don't get replacement RENIX injectors - get some Ford 302 stockers (19#, I think they've got an orange top) from someone who has upgraded, or from an outfit like FiveOMotorsports (they're online, www.fiveomotorsports.com, I think.)

To replace them, just pull the screws holding the fuel rail down, and pull the clips off of the injectors at the fuel rail to free them. Drop the injector and change the O-rings (a dentist's pick comes in handy for removal.)

TIP -
Have the new o-rings soaking in a small cup of gasoline before you start taking things apart - they'll seal faster.
If you disconnect the fuel line from the fuel rail, you'll need new seals for that as well. Might as well get those while you're about it at the dealer - I think they're in the $10-15 range as well.

Should take about an hour.

5-90
 
I was actually looking into the Ford 19's. So what about the Ford 19's from a H.O. Ford, the ones with 4 ports, will they work for me? If not will the Ford 19 gen 3's work?

Another option for me is to steal some injectors from my stoker in storage, they're 28 or 36 pounders, I forget which but they came from a 'Vette.

Just out of curiosity what are the Renix injectors stock, pound wise?
 
I would like the same answer. My dads 90 and my 89 rig both have a couple that are seeping now. 160K and 330K miles respectively.
 
Zoro said:
I was actually looking into the Ford 19's. So what about the Ford 19's from a H.O. Ford, the ones with 4 ports, will they work for me? If not will the Ford 19 gen 3's work?

Another option for me is to steal some injectors from my stoker in storage, they're 28 or 36 pounders, I forget which but they came from a 'Vette.

Just out of curiosity what are the Renix injectors stock, pound wise?
Click to expand...

Yep - the four-hole injectors are commonly held as an upgrade, simply due to better fuel atomisation.

You don't have enough displacement for the computer to adapt to the larger injectors - the stockers are also 19#.

5-90
 
Last edited:
andyr354 said:
http://www.fiveomotorsport.com/Injector_SetsJEEP.asp

Found it. So the single and 4 hole both work, the 4 hole is just "better"?

I am cheap so I might just goto the salvage yard and grab a set of 8 out of a core engine or two.
Click to expand...

Been there done that. From now on if I replace one injector, I replace them all with brand new ones. I also get a match set when I buy them. Makes a huge difference in performance, unless you get really lucky. I got my last set for less than $50 ea as I recall (wholesale online somewhere, four hole injector design). And they don't leak like the OEM injectors!!!:eeks1:

I use the old ones for paper weights.

Mike McGinness
South Houston, TX
 
andyr354 said:
http://www.fiveomotorsport.com/Injector_SetsJEEP.asp

Found it. So the single and 4 hole both work, the 4 hole is just "better"?

I am cheap so I might just goto the salvage yard and grab a set of 8 out of a core engine or two.
Click to expand...


Correct. The four-hole will give a much finer "mist" - liquid gasoline doesn't burn, atomised gasoline burns, and vapourous gasoline is explosive. Since the four-hole gets about the same port area as the one-holes - just in four rather smaller holes - the droplets formed when the gasoline is pushed through the holes is finer, which makes for more efficient combustion (don't confuse "economy" with "efficiency" tho - while you may pick up 1 or 2mpg, that's more a nice surprise than something you should expect...)

5-90
 
andyr354 said:
http://www.fiveomotorsport.com/Injector_SetsJEEP.asp

Found it. So the single and 4 hole both work, the 4 hole is just "better"?

I am cheap so I might just goto the salvage yard and grab a set of 8 out of a core engine or two.
Click to expand...

I got mine out of an Explorer at the wrecking yard. The motor had not been touched, so they were still sealed up. Been running them for two years with no problems and I paid $30 for all 6
 
Motornoggin said:
I got mine out of an Explorer at the wrecking yard. The motor had not been touched, so they were still sealed up. Been running them for two years with no problems and I paid $30 for all 6
Click to expand...

So my mistake was getting just two out of the junk yard to replace a dead one and a leaker. I should have replaced the whole set! Makes a lot of sense.

Mike McGinness
South Houston, Tx
 
All the sudden this morning all but the one closest to the firewall were leaking so I dumped a bottle of Lucas in as a bandaid until the new injectors get here.

Looks like 2 or 3 that were leaking have stopped leaking.

Could this have anything to do with a sudden temperature drop? Just wondering because it only started when the temps dropped like 40* the other day
 
The Renix injectors are shitty and prone to leak, so DON'T replace them with new OEM units. Do yourself a huge favor and replace them with orange top 5.0 Mustang 19lb/hr injectors (4-hole units are better). If you don't fancy spending the bucks at fiveomotorsport.com, check out ebay instead. They're cheap and plentiful.
 
Wish i had known the OEM injectors are crap before i replaced all 6 of mine this summer. Al least when they start leaking again i know what to replace them with now. I paid the same price for the OEM's that the ford's cost.
 
Dr. Dyno said:
The Renix injectors are shitty and prone to leak, so DON'T replace them with new OEM units. Do yourself a huge favor and replace them with orange top 5.0 Mustang 19lb/hr injectors (4-hole units are better). If you don't fancy spending the bucks at fiveomotorsport.com, check out ebay instead. They're cheap and plentiful.
Click to expand...

Diito. I got a set of 8 on eBay from a low mileage Mustang for $50. Best part, is that I still have 2 spares!

If you look around, you can find some great deals.
 
Zoro said:
Just started smelling gas yesterday so this morning I looked over the entire fuel system and found out that my two forward most fuel injestors are leaking from where they go into the intake manifold.

What causes this? FOD? Anyway to fix/save them or is time for new ones?

Also if I were to put some injectors in that are rated for a higher fuel pressure than stock would this alter the performance of my engine in a bad way?

1990 XJ 4.0 205K
Click to expand...
All you need to do is pull the injectors and replace the orings. Be sure and clean the oring seal area before reinstalling them. It is a real easy fix.:roll:

Mike McGinness
South Houston, TX
 
Zoro,

If your injectors are leaking from their installation location in the intake manifold you only need new o-rings. I just replaced the o-rings on my 1989 and removing the fuel rail from the engine compartment is the best way to do this on this model year (i.e., 1989).

Rick
 
Sabalon Glitz said:
Wish i had known the OEM injectors are crap before i replaced all 6 of mine this summer. Al least when they start leaking again i know what to replace them with now. I paid the same price for the OEM's that the ford's cost.
Click to expand...

It's only the Renix injectors that are leak-prone. The HO injectors are very reliable.
 
You must log in or register to reply here.

Similar threads

C
Could bad fuel-pump check valve cause stalling?
Replies
4
Views
2K
Runnin'OnEmpty
R
C
91 XJ missing at 2000 +rpm only when at operating temp
Replies
0
Views
1K
cptmiker
C
L
Fuel Pump Check Valve or leaky Injectors?
2
Replies
23
Views
4K
Lost_Wrench
L
J
'95 XJ 4.0 - Hard Start & Fuel Pump Frustration
Replies
8
Views
2K
old_man
old_man
A
Long crank when engine warm
Replies
15
Views
3K
aquaman788
A
Back
Top