Raw fuel smell.

My 89 4.0 has a raw fuel smell when it's running, but I don't see any signs of anything leaking. Is there something specific I should be looking for, or should I just get my fuel system checked?

Motornoggin said:

My 89 4.0 has a raw fuel smell when it's running, but I don't see any signs of anything leaking. Is there something specific I should be looking for, or should I just get my fuel system checked?

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DO NOT DRIVE YOUR JEEP until you find the source and correct it.

The '87 through '90 ("Renix") 4.0L fuel injection has injectors that can start to leak. When that happens, raw gas drips on the exhaust manifold. THIS IS A FIRE HAZARD! I have personally watched an XJ burn up because of this (fire melted the hood latch release mechanism so the fire department couldn't open the hood. By the time they cut it open it was much too late.) Several of our members have lost XJs due to this.

No foolin'. Don't drive it until you KNOW what the problem is, and you KNOW it has been fixed.

Those renix injectors most often leak where the molded plastic meets the metal part. I also had one leak out through the electrical connector. If you find one leaking, just replace the set. Many things are better purchased at the stealership, but I don't think injectors fit in that catagory. I think these were rated at 18.7 pounds, IIRC. I know AZ has replacements for much less than the cost at the stealership.

The stock (not high performance) 5.0 L Ford Mustang injectors are rated at 19 pounds and they fit right in. Many of the Mustang guys are pulling them out and replacing with 24 pound injectors. When my renix injectors went bad, I called a Mustang motorhead friend and he threw me 6 of his old ones for free. They are still working great after 2 years.

The best advice you will read here is what Eagle already said. DO NOT drive it until it is fixed.

I second (third?) what eagle said. I had a leaky injector on my 88 and replaced the o-rings (on ALL injectors) and the leak went away. The O-rings were $8.00 from the dealer, plus a tube of KY lube from CVS, (which I *didnt* already have, thank you)

Repeat, dont drive your XJ...you can drive it, it wont blow up, but you stand an excellent chance of starting a fire. If yoy need to drive it, like to get replacement injectors or o-rings, carry and extinguisher and leave the hood popped. :flame:

Annother place to look is at the quick connectors on the lines to the fuel rail. My 87 leaked at the return line several years before the injectors started leaking (they did that too, though). Like the injector leaks, these can be hard to spot unless you look at them while it's running. Gas is volatile enough that a little leak will disappear if you wait a moment.

Thanks for the info. It appears to be the #2 injector. I think I am gonna go for the 5.0 injectors if I can find them soon enough.

i got a similar problem with the quick disconnect fittings. Can anyone walk me through replacing them? Gonna do the ford injectors at the same time just for some more zip.

boogie94xj said:

i got a similar problem with the quick disconnect fittings. Can anyone walk me through replacing them? Gonna do the ford injectors at the same time just for some more zip.

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Time out!

The Ford injectors usually discussed are 19 lb/hour injectors from the 5-litre engine. They're fine for the non-HO XJ engines, which use an injector rated 19.6 lbs/hour.

Your screen name suggests that you have a '94. Your injectors are either 22 lb/hour or 24 lb/hour. Putting in 19-lb Ford injectors isn't going to give you more zip, it's going to make you run lean, and probably push the injectors into about a 100% duty cycle -- which they aren't designed to handle.

What about a super rich smelling exhaust problem eagle? My 88 stinks of gas if you stand behind it. New O2 already... thoughts?

Eagle said:

Time out!

The Ford injectors usually discussed are 19 lb/hour injectors from the 5-litre engine. They're fine for the non-HO XJ engines, which use an injector rated 19.6 lbs/hour.

Your screen name suggests that you have a '94. Your injectors are either 22 lb/hour or 24 lb/hour. Putting in 19-lb Ford injectors isn't going to give you more zip, it's going to make you run lean, and probably push the injectors into about a 100% duty cycle -- which they aren't designed to handle.

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So, is there any reason I shouldn't/couldn't install the HO injectors in my 89?

Motornoggin said:

So, is there any reason I shouldn't/couldn't install the HO injectors in my 89?

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on 89, you should use 19 # injectors. ho injector are rated at 22# or 24, like eagle said. if you use them you will run too rich.

Good catch Eagle. I do have a 94 but the injector job is going in my 88 mj. My 94 had the injectors replaced with the ford units with no troubles. What year did they change to the HO version?