Aftermarket Fuel Injectors

[sixty7ss]

I'm looking to replace my fuel injectors in the near future and I was wondering if any of you had recommendations for upgraded injectors. Are there any that are popular due to quality and performance?

 

[Ben824]

Use Dodge Neon injectors. P/N 0280155703 for 98 and older XJs and P/N 0280155784 for 99-01 XJs. The 703 injectors can be had from any 95-97 Dodge Neon, Caravan, Grand Caravan, Stratus, or Plymouth/Chrysler Breeze, Voyager, Grand Voyager, Cirrus, or Sebring with the 2.0L or 2.4L 4 cylinder engines. The 784 injectors can be had from any of the same vehicles listed above with the same motors listed above but from years 98-2000ish.

There is no difference between the 703 and 784 injectors other than the connectors. All of their specs are identical. The connectors for the 703 are the older EV1 style which
every XJ before 99 had. The 784 has the newer EV6 style connector that the 99-01 XJs have.

I picked up a set of the 703s for my 97 XJ from two junkyard cars and it was by far the most mileage and drivability improving engine performance upgrade that I have done to my Jeep and i have done nearly every common basic bolt on.

I was so impressed I recommended them to other XJ guys and they got them and had great results as well. I went back and got another set for my cousin's Jeep and we are just waiting for a good day to put them in his.

Junkyard score you are going to be looking at $50-$60 for a set. Online from a refurbished injector dealer you will be looking at $150-$175. Brand new you are looking at probably $200+. You may be able to find some refurbished on ebay for less than $150.

 

[fallacist]

Email LOSTSTAR1969atAOL.com

He sells em on cherokeetalk/forum. They're cleaned and tested, and WAAAAYYY less than the price on those refurbished one's from ebay.

He also seems to know his shit, and can answer any of your injector related questions.

I picked up a set of 784s from him, and am very happy with how everything turned out- obviously I'm recommending the guy and the injectors

 

[sixty7ss]

Awesome! Thanks, guys. So even though they come out of a 4cyl., they'll work on my 4.0L?

 

[sixty7ss]

And these improve performance over stock? Better mileage? More power? Forgive me if these are stupid questions. I can tear down and rebuild a Carter carburator and the 350 it's attached to, but I don't know anything about fuel injection.

 

[Ben824]

Yes the specs for the 703 and 784 injectors match the Jeep's OEM injectors, infact flow rate is a little bit better/higher and they have a four hole spray "nozzle" instead of the OEM injector's one hole. The four holes provide a finer "mist" spray pattern and the fuel is better atomized which creates a better more efficient burn. The more efficient burn means you get a better use of the fuel being used. All of this translates into better performance and mileage.

I put some of the 703s in my Jeep and wow I couldn't believe the improvement! My Jeep is on 33" tall tires and factory axle gears and I went from getting 13.5-14 mpg on the highway struggling to keep steady at 65 without having to downshift all the time, to getting upwards of 16.5-17 mpg doing 70-80 mph (depending on if there were strong winds that day) happily! I feel like the Jeep is much more drivable now. Before it felt like a slow turd and now it feels more peppy and holds speed better on hills. I have another set of 703s waiting to go in my cousin's 94 and I just picked up a set of 784s from the junkyard today that will go in my cousin's 99!

Again if you are not afraid of junkyard parts then that is the cheapest way to go. Otherwise go over to CherokeeForum and there are a bunch of guys selling both 703 and 784 injectors for $50-60.

 

[CobraMarty]

I just placed 703's in my '98. Work great!

 

[Paintballpsyco2369]

Going to be doing this same thing once I get my new head on and start getting it back together. Was going to hold off on the injectors, TB spacer and boring out the reducing ridge below the butterfly valve, but thinking I might just want to go ahead and do at least the injectors with the head, would make the intake K&N and the headers more worthwhile I think lol.

The only issues you may run into with your build, are if you build up a stroker or something. Of what I have read into the whole injector thing, these Neon injectors work but they work good with the stock fuel pressure regulator. If you start playing with those pressures, then you may need to go with one of the "Bosch or Ford" injectors that can handle more pressure... Best of luck with it all!

Paint

EDIT: Can the 784's be used in the 01's? Technically I have an 01 TJ that I want to get some more out of, and I keep finding TONS of the 784 injectors at my local yards. Thought they were in compatible due to the high FPR, maybe I am wrong on this?

 

[Talyn]

Yes the specs for the 703 and 784 injectors match the Jeep's OEM injectors,

They don't match. On the 49 psi fuel rail the 784s will flow around 24.5#.

 

[sixty7ss]

They don't match. On the 49 psi fuel rail the 784s will flow around 24.5#.

What does that mean? How will that affect performance?

 

[Ben824]

They don't match. On the 49 psi fuel rail the 784s will flow around 24.5#.

I said match as in close enough to work, not identical.

What does that mean? How will that affect performance?

The difference is small and will be a positive affect on performance. It is an increase over stock but within limits of what the Jeep EFI needs on a stock 4.0L engine to keep the air/fuel ratio in check. You will here of guys running 24# injectors for strokers or supercharged/turboed engines because they need more fuel which would be too much on a stock engine but those injectors are rated 24#/hr at 43.5 psi. All injectors are on every flow chart are rated based on a 43.5 PSI rate. This makes them all comparable. Engineers then do the math to find what injector they can use for their application based on the fuel pressure for the engine they are designing.

So you can run the 784s in your Jeep just fine they will be a nice upgrade which is what you are going for here.


I refer to you this very nice chart.

 

[Talyn]

I said match as in close enough to work, not identical.

You mean close enough to mess with the PCM and make a rich WOT even richer? Those injectors are large enough for a stroker and have no business being on a stock engine.

The difference is small and will be a positive affect on performance. It is an increase over stock but within limits of what the Jeep EFI needs on a stock 4.0L engine to keep the air/fuel ratio in check.

The difference is not small either. While the PCM maybe able to keep the AFR in check it doesn't not like the fuel trims straying far form 0. Using 24 lbs on a 4.0L will put the PCM around a -10 fuel trim and stinking rich at WOT.

You will here of guys running 24# injectors for strokers or supercharged/turboed engines because they need more fuel which would be too much on a stock engine but those injectors are rated 24#/hr at 43.5 psi.

No, usually they are 24#@ their fuel pressure. Case in point is the 703 injector. Me and a few others run that injector on stroker engines, which works out to around 24.5# on the rail. Taking an injector that is 24# @ 43.5psi will yield around 26# @ 49psi, which is even too much for a stroker.

This makes them all comparable.

Injector flow rates are not linear for the most part. So, when the fuel pressure changes they aren't as comparable as you think. Doing the math using a 43.5psi rating might give you an idea what it flows at 49psi

I refer to you this very nice chart.

That chart needs to be burnt.

 

[Ben824]

You mean close enough to mess with the PCM and make a rich WOT even richer? Those injectors are large enough for a stroker and have no business being on a stock engine.
The difference is not small either. While the PCM maybe able to keep the AFR in check it doesn't not like the fuel trims straying far form 0. Using 24 lbs on a 4.0L will put the PCM around a -10 fuel trim and stinking rich at WOT. No, usually they are 24#@ their fuel pressure. Case in point is the 703 injector. Me and a few others run that injector on stroker engines, which works out to around 24.5# on the rail. Taking an injector that is 24# @ 43.5psi will yield around 26# @ 49psi, which is even too much for a stroker. Injector flow rates are not linear for the most part. So, when the fuel pressure changes they aren't as comparable as you think. Doing the math using a 43.5psi rating might give you an idea what it flows at 49psi
That chart needs to be burnt.

Your responses are theoretical based on your mathematical calculations. These injectors work. They have good results by many who have tried them. I will take first hand experience over you playing with numbers. The 703s worked great in my 97 and the 784s will work great in my cousin's just like all the others that run 784s.

Point in case that your theory is flawed is the 19# Explorer injectors that by what your telling me would come out to be close to the stock needs of the 4.0L. I tried those as well and guess what? My performance was terrible and I lost fuel mileage. I cleared the PCM multiple times trying to get them to run right and ran them for 4 months. Finally tried the 703s and they worked great the first time! everything improved! These are real world results not a math calculation on paper.

 

[Talyn]

No, my responses are not theoretical. This is based on mine and other observations running injectors in strokers and 4.0Ls. What is your duty cycle using those injectors in a WOT condition? AFR in WOT? Fuel trims? I know what my data is on the 703s in my stroker. All points to them being ever slightly too large, not a lot, but the best fit I have found so far. If they are just a little too larger for a stroker you think that are the correct size for a stock 4.0L?

Just because something appears to work does not make it a good fit.

Also, salvage yard injectors aren't a good idea as you experienced with the Explorer injectors. They tend to be clogged.

Point in case that your theory is flawed is the 19# Explorer injectors that by what your telling me would come out to be close to the stock needs of the 4.0L. I tried those as well and guess what? My performance was terrible and I lost fuel mileage. I cleared the PCM multiple times trying to get them to run right and ran them for 4 months. Finally tried the 703s and they worked great the first time! everything improved! These are real world results not a math calculation on paper.

I have eight Ford 19# injectors for sale. I ran them for a little while with absolutely no problems.

 

[Doubleajaybrock]

so 784's are correct for a '99 then right?

 

[Ben824]

so 784's are correct for a '99 then right?

Yes the 784s are correct for the 99-01. They also for can be for some mid-98s just have to check the Jeep itself to see what connector it has.

 

[Ben824]

No, my responses are not theoretical. This is based on mine and other observations running injectors in strokers and 4.0Ls. What is your duty cycle using those injectors in a WOT condition? AFR in WOT? Fuel trims? I know what my data is on the 703s in my stroker. All points to them being ever slightly too large, not a lot, but the best fit I have found so far. If they are just a little too larger for a stroker you think that are the correct size for a stock 4.0L?

Just because something appears to work does not make it a good fit.

Also, salvage yard injectors aren't a good idea as you experienced with the Explorer injectors. They tend to be clogged.

I searched the internet for about 6 months and found tons of data and first hand accounts. A small amount said what you are saying. More said they worked. I tried the V8 explorer's injectors and they didn't work. Only benefit I got out of those was the smoother idle. But driving around they were very lacking. So I tried the 703 injectors and had a world of improvement! I have had my Jeep for a very long time modifying it all along the way. I am very conscious on monitoring it and keeping up with maintenance. One of these things is doing the math to see what kind of mileage I get out of every tank I use after EVERY time I fill. I also regularly run fuel cleaner through my Jeep and I have had shops do professional BGK cleaning over the years as well, one shop said my Jeep didn't even need the treatment because when they performed the procedure very little white smoke came out the tailpipe. How much white smoke tells them how dirty the fuel system and engine are. I lost half a mile to a full mile per gallon with the V8 explorer injectors after running them for 4 months, cleaning them, and running fuel cleaner through system. I then went with the 703 injectors and picked up 2-3 mpg over stock! The Jeep also maintains speed going uphill compared to before. These are real world driving results.

From what you are telling me you are comparing things on a stroker motor. Also lets say you are correct, you are telling me that the problem lies at WOT. Well I don't know what you do with your Jeep, but mine almost never sees anything over 3800 rpm. I drive more conservatively to save gas. And my Jeep will never see a track where I would be hitting the red-line at WOT.

And yes, they were clogged and I then took them out and cleaned them thoroughly letting them soak in cleaner (what re-furb sellers like precisioninjectors.com do) and put them back in and they performed fine other than the they were not right for my Jeep's fuel needs.

To the OP run the 784s in your 2000 just like many other have with positive results. If they give you poor performance and you loose mileage, then take them back out and re-sell them in your local chapter, some one will buy them.

 

[Talyn]

one shop said my Jeep didn't even need the treatment because when they performed the procedure very little white smoke came out the tailpipe. How much white smoke tells them how dirty the fuel system and engine are

White smoke tells you nothing about the fuel system. It just tells you that there has been carbon removed. If you have carbon in your fuel system you have other problems.

From what you are telling me you are comparing things on a stroker motor. Also lets say you are correct, you are telling me that the problem lies at WOT.

No, I am telling you that they aren't a good fit for a stock 4.0L, which I also have one of as well. If they run a bit rich with a stroker, you think they are a good fit for a stock engine (including ones with bolt ones aside from forced induction)? And its not just at WOT. At WOT it really becomes evident. The PCM likes fuel trims as close to 0 as possible. The engine runs better and is more efficient. I can guarantee yours are around -12 or lower.

And yes, they were clogged and I then took them out and cleaned them thoroughly letting them soak in cleaner (what re-furb sellers like precisioninjectors.com do) and put them back in and they performed fine other than the they were not right for my Jeep's fuel needs.

Lol. Simply letting injectors soak in injector cleaner isn't even close to what injector refurbishers do.

Do you actually have any real data besides fuel mileage to back your claims up? Fuel ratios? Injector duty numbers? Fuel trims?

 

[kndrewa]

No, I am telling you that they aren't a good fit for a stock 4.0L, which I also have one of as well.

I'm not on either side of this argument here, but curious what you like to run in your Jeep with the stock 4.0L? OEM replacements? Is there another alternative which doesn't cause the fuel trim issues?

 

[Talyn]

For the 97+ 49psi fuel rail I would recommend the Ford YR3E-A4A or the XF2E-C4B.