just want to share my results from the 703 injector swap. I did 0 prep on the injectors. I got them from the junkyard and simply swapped them out. I did change a couple orings on the 703s that were questionable with ones that were on my old injectors.

the jeep starts much quicker now. it had a pretty smooth idle before, but is a tad smoother now and doesn't gurgle as much when standing and listening to the exhaust.

I didn't notice any difference in throttle response, as it was already quite responsive. I didn't notice any increase in power, either. what I did notice is that it takes more pedal to achieve the same rate of acceleration and to maintain speed (ie: on hills), as well. I only have about 50 miles on them. i reset the computer before driving it after the swap. I am curious to see what kind of impact it will have on my mileage. I was getting consistent 22+ beforehand. i'm at 1/4 tank, so i'll update this thread with mileage results in a couple weeks after I fill it up and run a full tank through it. I threw in some seafoam this afternoon.

it was an easy swap. took me roughly 30 mins hood up to hood shut. there was all kinds of gom where the injector seats in the intake, so i used my shopvac and a pick to scrape everything out.

there was nothing wrong with my old injectors, but i am very happy to see how quickly it starts now. i'm afraid of losing mileage, but as long as it stays over 20 i won't bother putting the stock ones back in.

the only tools i used were a ratchet, 1/2" socket (for the battery terminals), 10mm socket (for the fuel rail bolts), pick, and shop vac. oh and i lost the cap that goes on the Schrader valve used to check/release fuel pressure. sigh...

 

what model xj do you have?

 

97 2dr xj - 4.0 aw4 np231 c8.25 - stock

 

would the 703s fit my 2000 i think they have the ev6 connectors .what # ate they. Im interesyed in this mod

 

Why did you do this mod? What were you hoping to gain?

Bird

 

I did the same mod to my jeep, and also had a improvement in the start up. Havent had time to calculate the differences (not driving due to extensive mods in progress) but ill get back to you.

 

i have these injectors on mine and felt a huge difference.

but i also have them paired with a full exhaust/ bored throttle body/cowl(cold air) intake/ IAT relocation/ clutch fan delete.

the more performance mods you have the more they all start working together

 

Yeah, i installed new headers free flow exaust system rebuilt the motor, tbs, and high octane fuel so the difference isnt from the injectors alone

 

did the swap out of boredom mainly. I plan on installing an obx header, new 2.5" exhaust on it and making a homemade ram/cold air setup. wasn't expecting to gain anything, to be honest. more of an FYI swap. hopefully my experiences will help someone else with the decision and/or results.

 

It almost sounds like you and I are working from the same checklist, only starting from opposite ends. In the last year I've done the 2.5 exhaust, APN header and homebrew cowl intake; and I'm gonna do injectors and 62mm TB after I get done with skid plates.

One thing I've noticed in the last few years is that after you do a mod to the 4.0 and then reset the ECU, it almost always feels sluggish for the first week. Then as the computer adjusts (supposedly takes 50 start cycles to adjust fully) it gets more responsive and the MPG improves. I noticed the APN header and exhaust right away added power and then it still got better MPG and more responsiveness after things adjusted. At first it always makes me say "great, don't tell me I'm gonna have to undo all that crap I just did..." but then I'm always pleased with the results. Give it time if it seems like a step back at first!

 

Agreed on giving it some time. It wouldnt be such a well known mod if there wasnt some improvement.

 

you need 784 injectors

 

I'm thinking about doing this mod. Currently I have no engine mods and 31's on steelies is killing my mpg.

 

Do it! Its easy and cheap, im ridding steel wheels to so i feel you

 

Which vehicles can the 784's be found?