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What's the best swap? I've done a lot of research lately on this subject and come to a ton of different conclusions.
703 injectors from the neon are great for 39psi fuel rails, but I have a 98 cherokee that has a 49psi rail and therefore the flow rate would be too high, and my cherokee would run rich, and extremely rich at WOT. So I have eliminated those, which leads me to the next options.
XF2E-C4B injector from I believe a Taurus and some other Ford applications. These injectors have a 4 hole nozzle, and I believe would fit right in, but after doing they math I am finding that they will have a flow rate even less than the stock injectors. Not sure if this will have any consequence as it's about 2/lbs an hour less, but in my experience with motors I prefer to not run anywhere close to lean if I can help it. Anyone have hands on experience with these? They seem like the best fit for my application because of the spray pattern, and not running too rich, but I am still undecided. Also I am not sure if these are ev1 or ev6 and if I'll need an adapter or not.
The next option is the YR3E-A4A, which I thought seemed like the best fit, as they flow closest to OEM spec, but then I realized that they are only a 1 hole nozzle, same as the OEM injectors so I really have no clue how those would be an upgrade.
I don't know much about this stuff, this is just what I've found online through many hours of surfing threads. I feel like I am running in circles. I would like some opinions on what my best option is for a different injector on a 98 Cherokee or what you guys are running and how it's worked out for you. Thanks in advance.
You are over thinking this. Everyone & I mean EVERYONE uses the 703s. Get a set, throw them in & thank me later.
The majority of cherokees have a 39psi rail though, which would explain why most people use them. The 98 has a 49psi rail, which is a substantial difference. I've seen actual data and fuel trims that show the 703s are pig rich on a 49psi rail, they put out slightly too much fuel for even stroker motors. They work great for almost every cherokee that's been released, but not so much for the 49psi rail. Cherokees are already rich enough at WOT, adding more flow just doesn't make sense to me. I am just trying to find an ideal fit, as I can find most these injectors for around the same price anyways.
The XJ in my avitar is a '98. I installed the 703s & noticed a vast improvement in performance and mpgs. Seriously, how many times are you ACTUALLY at WOT? Personally I have never seen it & if you do you're probably doing it wrong. The 4.0 is a glorified tractor motor that likes lower rpms to make good torque. It's not a motor that's meant to be repeatedly bounced off the rev limiter.
Again, get a set of 703s, install them & thank me later.
Works GREAT. Truck runs so much better with new injectors. Maybe 1-2mpg increase over 200k mile old stock injectors, but faster to start and a smoother idle were worth it to me.
Edit: I almost never Rev past 4k RPMs - the Jeep 4.0 just doesn't make power above that RPM and it's better to shift early to utilize the lower powerband of the L6
right now I am running ford 4 hole injectors from a Mustang. 2002 Ford Mustang 19# Fuel Injector swap (#0280-150-556/FDTE-D5B). They work very well even at 4k rpms and run very nice with the bored out throttle body.
It took me about 45 min to install all six. and the stock clips work too.
I just looked at the specs again for the Injectors that I am running and it flows 210cc at 3 bar pressure (43.5 psi) and 14.4 ohms. So they are slightly more then the 710's.
I'm a noob to anything more than the basics around an engine, but I do own a 98 and am curious. What's wrong or inferior about the stock injectors?
The stock injectors only have one nozzle hole, so upgrading to the 703s (which are the same size as stock) gives the same amount of fuel spray, but does so more efficiently by having four spray holes. It improves MPG, idle, acceleration. There are a lot of threads on the topic if you search around the forum a bit.
The XJ in my avitar is a '98. I installed the 703s & noticed a vast improvement in performance and mpgs. Seriously, how many times are you ACTUALLY at WOT? Personally I have never seen it & if you do you're probably doing it wrong. The 4.0 is a glorified tractor motor that likes lower rpms to make good torque. It's not a motor that's meant to be repeatedly bounced off the rev limiter.
Again, get a set of 703s, install them & thank me later.
After doing some more math I'm realizing that the 703s only flow like 1/lb an hour more than the stock injectors @ 49psi. The difference seems mostly negligible. It will still be slightly richer than stock all the time but not enough to really matter. Chances are I'll just throw the 703s in and deal with it. Just want to make sure I'm spending my money on the most useful stuff possible for my cherokee. Thanks for the input
After doing some more math I'm realizing that the 703s only flow like 1/lb an hour more than the stock injectors @ 49psi. The difference seems mostly negligible. It will still be slightly richer than stock all the time but not enough to really matter. Chances are I'll just throw the 703s in and deal with it. Just want to make sure I'm spending my money on the most useful stuff possible for my cherokee. Thanks for the input
It will NOT "be richer". The fuel injection system adjusts the duty cycle of the injectors to maintain a proper fuel mixture.
It will NOT "be richer". The fuel injection system adjusts the duty cycle of the injectors to maintain a proper fuel mixture.
Listen to Big David.
Originally Posted by cruiser54
It will NOT "be richer". The fuel injection system adjusts the duty cycle of the injectors to maintain a proper fuel mixture.
Listen to Big David.
Yes it will be richer. While the system can adjust the duty cycle, increasing the flow rate of your injectors increases the fuel delivered. The pulse duration can be controlled, but the fact is that these injectors flow more and they have a four hole nozzle as opposed to the OEM single hole. More fuel is going to flow per pulse. It's not substantial, but I'm not sure why you are trying to argue that it won't change the AFR at all. The rail is 49psi. The 703 injectors flow more than the stock injectors. I already said the difference isn't much and I will probably run 703s provided I don't find a better alternative. Regardless, attached is actual data of short term fuel trims with stock injectors vs the 703 injectors. The fuel trims of the 703 are a richer mixture. Period. At various speeds. It's not a huge difference, but it's quite obvious they are pulling more fuel than the stock injectors are.
The 703s are still fine to run. A lot of the performance gains people see are because their injectors are 100k-200k+ miles old anyways. Replacing 20+ year old injectors with brand new ones is going to help.
01-30-2016, 06:41 PM
98 Cherokee Injectors
