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Injector upgrade for 4.0 ZJ - Anything better than 703's?

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Old 01-31-2017, 06:03 PM
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Default 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.
Old 01-31-2017, 06:12 PM
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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.
Old 02-01-2017, 09:59 AM
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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.
Old 02-01-2017, 01:18 PM
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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.
Old 02-03-2017, 04:19 AM
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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.
Old 02-03-2017, 05:03 PM
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I'd be willing to bet they are Chinese. I bought a set of reconditioned Bosch for $150.
Old 02-10-2017, 04:46 PM
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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%.


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