Order of work

[NC Tom]

Folks, my MJ is having all kinds of issues. As I look for one, I find another. It runs well and it is my DD. My most pressing issue is a strong fuel smell. The rubber lines connecting to the fuel filter were leaking, so I replaced those. However, that didn't fix the issue. I stopped by a garage today to talk to a mechanic about it. Upon first look into the engine compartment, he noticed an injector was wet. Could be the problem? The engine was smoking a bit when we lifted the hood and he said the valve cover gasket was leaking which explains why my cover and other components are covered with a thin film of oil. Honestly, I thought that was from normal wear and age. However, I do burn oil. Also, a neighbor suggested I check the fuel tank gasket. Okay, maybe that's the problem? Or, maybe they are ALL the problem?

 

So, would a leaking valve cover gasket account for a wet injector? If so, do I replace the valve cover gasket before replacing the injectors?

I will use a Fel-Pro gasket.

Anybody have any experience with these injectors?

https://www.amazon.com/JDMON-Compatible-0280155710-0280155700-1987-1998/dp/B087CV8BLW/ref=sr_1_4?qid=1674855794&s=automotive&sr=1-4&vehicle=1988-42-348-334-34-31-8-8-3364-244-8-2-1766--3&vehicleName=1988+Jeep+Comanche

 

or, do I replace the gas tank gasket? Is there a gas tank gasket? Only one I can find is on the gas cap.

 

Thanks everybody.

 

[rokinn]

I'd start with the injectors first.  Fuel leaks in the engine bay is especially dangerous.  You may start a fire.

 

The fuel pump gasket is on the side of gas tank, passenger side.  You should be able to see if it is leaking.

 

Replace valve cover gasket and then go to the car wash and clean the engine.  Don't pull the trigger where there are sensitive components.  I've never had a problem this way.  I would probably do this first since I hate working filthy engines.

 

 

[Limeyjeeper]

I agree with Rokinn. Clean the engine first and then see if the injector gets wet again by running the engine. Sniff the liquid to see if it is gas and not oil. If it smells like gas look to see if it is coming from the top, bottom or body of the injector. There is an o ring at the top and bottom of the injector usually these injector o rings go first. Pretty unusual for an injector body to leak. 

Fixing the valve cover gasket is easy. Check you PCV valve and make sure it is not blocked. That can cause pressure in the top of the engine and cause the cover to leak.

[cruiser54]

THE HISTORY OF THE 4.0

BEST INJECTORS FOR RENIX

AUGUST 6, 2016 CRUISER54 182 COMMENTS

The original Renix injectors made by Siemens-Deka were only “one holers”. That means the fuel was discharged through only one hole.

Not the most efficient design by today’s standards. Modern injectors have at least 4 spray holes for better fuel atomization.

Another issue is the original injectors were prone to leaking fuel at a seam and spraying gas all over hot manifolds. Not good!!

A nice upgrade is to use Volvo injectors. The use of these injectors was pioneered by Programbo from Cherokee Forum when he suggested them to DFlintstone there.  Flintstone was the guinea pig and reported excellent results. I have experienced the same results as have many others. The 746s, as they’re called, have the 4 hole design  and the complete Bosch part number is 0 280 155 746. 

These injectors can be purchased refurbished for not much money and are a direct bolt-in.

WARNING: AVOID THE CHICOM KNOCKOFF INJECTORS!!!

BUY ORIGINAL BOSCH/VOLVO REFURBISHED INJECTORS HERE IN THE USA.

Trevor.skankfootracing@gmail.com

You will experience smoother idle and better throttle response. Perhaps some MPG improvement also.

[NC Tom]

 

On 1/27/2023 at 11:22 PM, cruiser54 said:

 

I did contact Trevor a year ago and he had a set of the 0280155700 for Renix trucks for $180.00 w/3 years warranty. Great price and a solid warranty. However, I need to stretch my dollars as far as I can. https://www.injectorplanet.com/?ref:MjcyNTU4LjU4LjI3NDg2NS5U had a reman set of the 0280155700 for $115 shipped. Less warranty but, at that price, I could get the Felpro valve cover gasket at the same time. I hope my research doesn't fail me. I found no negative info about injectorplanet.com and what I did fine appeared legit. Unlike motormanfuelinjection.com. Who I researched and decided to stay far, far away!

[NC Tom]

On 1/27/2023 at 6:14 PM, Limeyjeeper said:

I agree with Rokinn. Clean the engine first and then see if the injector gets wet again by running the engine. Sniff the liquid to see if it is gas and not oil. If it smells like gas look to see if it is coming from the top, bottom or body of the injector. There is an o ring at the top and bottom of the injector usually these injector o rings go first. Pretty unusual for an injector body to leak. 

Fixing the valve cover gasket is easy. Check you PCV valve and make sure it is not blocked. That can cause pressure in the top of the engine and cause the cover to leak.

Thanks! I'm just going to replace the injectors with, hopefully, better ones.

[NC Tom]

On 1/27/2023 at 5:22 PM, rokinn said:

The fuel pump gasket is on the side of gas tank, passenger side.  You should be able to see if it is leaking.

Thanks! I'll take a looksee!