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Injectors

lawsoncl

NAXJA Forum User
Location
North Idaho
I need to replace the injectors in my 89 MJ. Since it got really cold (5*F), I'm getting that telltale whiff of gas in the morning and it's taking longer to start. Sure enough #1 was wet when I looked. Might be just an o-ring, but they're rusty as well. I did a whole bunch of searching and have a ton of semi-conflicting info on replacements.

I believe I have oem 53003956 injectors as the olds ones look like they have 3956 stamped in them. Are rebuilt Bosch 0280155703 still the best replacements? Looking to do this relatively cheap.
 
Here are the stock specs for XJ's.
http://www.jeep4.0performance.4mg.com/tech_specs.html


Here are flow rates by Bosch #, scroll down to number needed.
http://www.fuelinjector.citymaker.com/Fuel_Injector_Flow_Rates.html

The following is pretty much what most go by when replacing Jeep injectors.

87-90 4.0 - Bosch 0280155746, from Volvo's.

91-98 4.0 - Bosch 0280155703 from late 90's dodge Neons and few others. Some people use Bosch 0280155710/0280155700, From old Ford V-8's if I remember correctly.

99-04 4.0 - Bosch 0280155784 from late 90'sand early 2000 Dodges Neons as well.

The 703 and 784 have a different plug, same injector.

I should add I put in 19lb. mustang injectors years ago when they were the thing to do. Still running them just fine.
 
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I got these Bosch 0280155746 in my 88. The fuel trims are right in spec on the ecu.
I did get mine off of ebay but they claimed to be flow tested. They have been working fine for 1 year so far and was roughly $65 used.
 
They're generally refurbished Bosch Volvo injectors. Contact the guy from cherokee forum.

Thanks again for the pointer. I just installed a set of 746s from John ( jhc7399) on cherokeeforum who charged $70. They are used that he's cleaned and tested. I doubt they're any different from the other refurbished on eBay for about the same price, but I'd rather support another Jeeper. I was also confident that he actually tests them. He also confirmed my suspicion that the "new" ones on there are chinese knockoffs.

The install went relatively smoothly, no leaks, and the injectors worked fine for a test run up the street and back. I ended up removing the injector retainer clips and pulling the rail off the injectors first, then prying the old injectors out of the intake. Those suckers were stuck pretty tight. The fuel line connectors popped in and out with no problem at all. The only real surprise was finding the airbox jammed completely full with a mouse nest. I only decided to look at the filter because the rubber intake hose looked pretty dirty.
 
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