Injector upgrade for 4.0 ZJ - Anything better than 703's?
#1
Member
Thread Starter
Injector upgrade for 4.0 ZJ - Anything better than 703's?
Seems like most people go with Bosch 0280155703's, but the last write-up I found was from 2011. Any better ideas since then?
Also, I may have a few 500+ mile trips on the same route coming up, so whatever I upgrade with, I'll do my best to drive them exactly the same and see if there is any noticeable MPG gain.
Also, I may have a few 500+ mile trips on the same route coming up, so whatever I upgrade with, I'll do my best to drive them exactly the same and see if there is any noticeable MPG gain.
#2
CF Veteran
Join Date: Oct 2016
Location: CA
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Year: 1994
Model: Cherokee (XJ)
703's are about as good as it gets, either find a junkyard set and rebuild them or there is a member in the vendor section who rebuilds/tests them and sells them for a reasonable price.
You may not notice any MPG increases unless your stock injectors are extremely dirty or not functioning properly.
You may not notice any MPG increases unless your stock injectors are extremely dirty or not functioning properly.
#3
Senior Member
when I installed mine starting seemed to be quicker and the idle a touch smoother, although my IAC was plugged pretty badly at the time. after I cleaned out the IAC it idled better (smooth), but stock might have been the same I just don't know. overall no complaints on the upgrade.
#4
Old fart with a wrench
Yes, I didn't notice any additional mpg, but I noticed quicker throttle response and a smoother idle. My original Siemens cases were cracking. The whole point of 4 hole injectors is a finer fuel droplet pattern for better combustion. The computer controls in amount of fuel needed so I don't see this makes a difference in mpg.
Last edited by dave1123; 02-02-2017 at 04:33 PM.
#5
Member
Thread Starter
What are the odds these are actually genuine and new?
http://www.ebay.com/itm/112170650096?ul_noapp=true
I sent the seller asking about them and they said "Thank you, this is high quality aftermarket part " Not quite sure what to make of that.
http://www.ebay.com/itm/112170650096?ul_noapp=true
I sent the seller asking about them and they said "Thank you, this is high quality aftermarket part " Not quite sure what to make of that.
#6
Old fart with a wrench
I'd be willing to bet they are Chinese. I bought a set of reconditioned Bosch for $150.
#7
Member
Thread Starter
Went ahead and got some refurbished Bosch 703's from the bay. Bought them from dimarmotorsportsllc. All were individually bagged and sealed with a silica gel pack. All of them look great, but one had what looked like a bit of corrosion around the injector holes. Contacted the seller and within a couple hours they had shipped out a replacement. Highly recommend them. Oh, and they apparently flow match them to <1%.