Fuel injector upgrade for the 4.0, and how to?
#1
Seasoned Member
Thread Starter
Fuel injector upgrade for the 4.0, and how to?
What's this I've been reading on the fuel injector upgrade for the 4.0? I've had my 96 XJ since 2006 and had the same injectors all that time. It's always had a little misfire even after a tuneup so I figure I might as well try this upgrade, especially since I saw one report of it only costing like 30 something bucks from ebay. Maybe those are used injectors?
Is this worth it and what model injectors should I be looking for?
Also, in a vid I saw there was a lot of gunk around the hole the injector came out of. One guy said to clean it up with a q tip soaked in carb cleaner. Another said to scrape it out with a screwdriver. When I do my plugs I just blow everything out real good w/ compressed air before I take them out. Should I do this same step when doing the injectors? This would be the first time I've taken the fuel rail or injectors out btw.
Is this worth it and what model injectors should I be looking for?
Also, in a vid I saw there was a lot of gunk around the hole the injector came out of. One guy said to clean it up with a q tip soaked in carb cleaner. Another said to scrape it out with a screwdriver. When I do my plugs I just blow everything out real good w/ compressed air before I take them out. Should I do this same step when doing the injectors? This would be the first time I've taken the fuel rail or injectors out btw.
#3
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Join Date: Mar 2014
Location: Cincinnati, Ohio
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Year: 1999
Model: Cherokee
Engine: 4.0
Thanks for the plug Earl.
For a 96 you want the real Bosch 703's.
The reason why I say real is because china is flooding ebay with cheap counterfeit crap "new" injectors for like $50 a set shipped. I have talked to a few people who have had issues with these. Even though they say "lifetime warranty" have fun taking care of a warranty issue dealing with a Chinese company. Not only that the free shipping can take up to a month.
Also a lot of the cheap "Jeep upgrade" injectors on ebay aren't even close to the flow of the original injectors. They just throw any injector they come across at the junk yard or what ever they have at the time out there and call it a jeep upgrade injector because it has 4 holes and the same plug.
If you do not buy ultrasonically cleaned, tested and rebuilt injectors you are just putting another dirty used injector in place of a dirty used injector and that really doesn't help anything.
Some people claim to get better mpg, some say their mpg went down after the swap. A lot of people do claim a better idle and smoother acceleration. Your results may vary.
They install is pretty simple, maybe an hour of work. There are quite a few tutorials out there. I think there is one here on the forum in the "How To" section.
Edit: Dukie has one here.
https://www.cherokeeforum.com/f51/in...ap-4-0l-92149/
For a 96 you want the real Bosch 703's.
The reason why I say real is because china is flooding ebay with cheap counterfeit crap "new" injectors for like $50 a set shipped. I have talked to a few people who have had issues with these. Even though they say "lifetime warranty" have fun taking care of a warranty issue dealing with a Chinese company. Not only that the free shipping can take up to a month.
Also a lot of the cheap "Jeep upgrade" injectors on ebay aren't even close to the flow of the original injectors. They just throw any injector they come across at the junk yard or what ever they have at the time out there and call it a jeep upgrade injector because it has 4 holes and the same plug.
If you do not buy ultrasonically cleaned, tested and rebuilt injectors you are just putting another dirty used injector in place of a dirty used injector and that really doesn't help anything.
Some people claim to get better mpg, some say their mpg went down after the swap. A lot of people do claim a better idle and smoother acceleration. Your results may vary.
They install is pretty simple, maybe an hour of work. There are quite a few tutorials out there. I think there is one here on the forum in the "How To" section.
Edit: Dukie has one here.
https://www.cherokeeforum.com/f51/in...ap-4-0l-92149/
Last edited by jhc7399; 10-13-2017 at 01:19 PM.
#4
Seasoned Member
Thread Starter
hmm, well, hmmmmmmmmm. Yeah somewhere in that reading I remember something about 'results may vary.' Wish there was more consistent results with this one. Wonder what other factors are involved concerning the better/worse gas mileage?
#5
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Join Date: Aug 2011
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Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Don't get your hopes up about mileage increase. It isn't there.
As to a misfire, could be worth doing.
As to a misfire, could be worth doing.