Did the injector swap...and WOW!
CF Veteran
Joined: Oct 2008
Posts: 1,052
Likes: 0
From: Wyo
Year: 1996
Model: Cherokee
I haven't read all of the replies yet, but be careful with your math. Seafoam in your fuel itself will increase your fuel economy to some degree (not likely the full 4.5 mpgs but some). It raises the octane as I understand it. It is REALLY noticeable in my motorcycle!
s
s
Junior Member
Joined: Apr 2010
Posts: 47
Likes: 0
Model: Cherokee
Thanks for the answer rainman, I am going to swap these out next Friday when I get back home, I was just expecting to see 4 holes when I opened them up and I wanted to make sure I didnt order the wrong thing.
Member
Joined: Mar 2010
Posts: 159
Likes: 0
From: Illinois
Year: 1988
Model: Cherokee
Engine: Renix 4.0
+1 on the injector swap, install the 703's yesterday, went to a pick and pull and pulled 4 out of a 97 2.4 stratus and 4 out of a 96 2.0 neon. You can easily spin the injector while its still in the fuel rail and see the numbers on the side. a lot better throttle response, and pulls a little harder. I stopped by autozone and picked up three. boxes of new o-rings. Four come in a box so you need three. And by the way, they are a B*tch to get in. I used a little pb blaster, took out the entire fuel rail, and pressed them in, some needed a little tapping. The new o-rings are stiff and dont want to go in.
good luck to anyone doing this mod, i'd say its worth it.
next - cleaning the cat.
good luck to anyone doing this mod, i'd say its worth it.
next - cleaning the cat.
Thread Starter
Junior Member
Joined: Apr 2010
Posts: 81
Likes: 1
From: Grand Haven, MI
Year: 2001
Model: Cherokee
Engine: Stock
I am beginning to think that had something to do with it, as I have not gotten anything close to that gas mileage since.
Does Seafoam really make that big of a gas mileage difference? The other thing that I was thinking is that the station I filled up at may not use ethanol in their fuel either. Just a thought?
Member
Joined: May 2009
Posts: 138
Likes: 0
From: NW PA
Year: 2000
Model: Cherokee
Engine: 4.0
I have put in the 784's in my 2000. At first everything seemed cool. now after a few weeks of having them in, I am actually starting to get a stumble on start up. Once I hit the gas it seems to clear up, but am not seeing the increase in mileage I was getting. I'm wondering if an injector or two are bad. how do I check to see if I have a bad injector, and which one(s) are bad?
Maybe I should have gotten new or refurbished ones.
Maybe I should have gotten new or refurbished ones.
Member
Joined: Oct 2008
Posts: 115
Likes: 3
From: Baltimore, MD
Year: 2001
Model: Cherokee
Engine: 4.0L 242ci 6cyl
I have put in the 784's in my 2000. At first everything seemed cool. now after a few weeks of having them in, I am actually starting to get a stumble on start up. Once I hit the gas it seems to clear up, but am not seeing the increase in mileage I was getting. I'm wondering if an injector or two are bad. how do I check to see if I have a bad injector, and which one(s) are bad?
Maybe I should have gotten new or refurbished ones.
Maybe I should have gotten new or refurbished ones.
Next you may want to check the Ohm's on each injector. The 784's should have an Ohm reading of 12.9.
http://injector-rehab.com/kbse/flowrates.htm
If you have a large fluctuation between injectors, the lower one or ones could be bad.
Member
Joined: Jun 2009
Posts: 150
Likes: 1
Model: Cherokee
I have put in the 784's in my 2000. At first everything seemed cool. now after a few weeks of having them in, I am actually starting to get a stumble on start up. Once I hit the gas it seems to clear up, but am not seeing the increase in mileage I was getting. I'm wondering if an injector or two are bad. how do I check to see if I have a bad injector, and which one(s) are bad?
Maybe I should have gotten new or refurbished ones.
Maybe I should have gotten new or refurbished ones.
ie. Does it happen when the engine is stone cold? or just when it has been driven, left some minutes and stumbles on start up when warm?
As for re manufactured injectors, well .......yes. Personally I think that replacing 10 year old injectors that were not working right with 10 year old injectors from a wreck of unknown condition is asking for trouble.
Considering how much damage can be done by a faulty injector I think $150 for re manufactured injectors is very cheap insurance.
Or in your case you can get new or near new Ford XR3Z 9F593 A4B / XR3E 9F593 A4B (MOTORCRAFT #CM-4956 ) for around $60.
good luck with it.
Last edited by rainman; Apr 25, 2010 at 05:11 PM.
CF Veteran
Joined: Oct 2008
Posts: 1,052
Likes: 0
From: Wyo
Year: 1996
Model: Cherokee
I am beginning to think that had something to do with it, as I have not gotten anything close to that gas mileage since.
Does Seafoam really make that big of a gas mileage difference? The other thing that I was thinking is that the station I filled up at may not use ethanol in their fuel either. Just a thought?
Does Seafoam really make that big of a gas mileage difference? The other thing that I was thinking is that the station I filled up at may not use ethanol in their fuel either. Just a thought?
I don't know how much you put in a full tank of gas, but I highly doubt one can per tank would net you all that much better of fuel economy. I don't know though. I don't bother with the math to figure out my fuel economy one way or another so I don't think I could even make an educated guess.
I do all sorts of stuff with my jeep so I am not consistent enough with my driving style to test it out even if I were to start measuring out my fuel usage.
s
Junior Member
Joined: Apr 2010
Posts: 85
Likes: 1
From: Phoenix, AZ
Year: 1988
Model: Cherokee
Engine: 4.0 Ltr I6
i have a 88 4.0 automatic stock gears (as far as i know) and 33 inch tires. i get 17 in the city. that is compensating for the tire size. and ive even goten 20 in the city with some fwy driving.
i find this very odd because ive NEVER seen or had a jeep that got that good gas mileage stock. adding bigger tires would make it worse. plus i have a cut out issue with my engine that would make it worse to.
could someone that owned it before me done this swap already?
im sure the gears are 3:55 because when i go up hill it bogs down like every other jeep ive had with 33 inch tires.
and trust me ive calculated this mpg evry fill up for the past 5k miles.
i find this very odd because ive NEVER seen or had a jeep that got that good gas mileage stock. adding bigger tires would make it worse. plus i have a cut out issue with my engine that would make it worse to.
could someone that owned it before me done this swap already?
im sure the gears are 3:55 because when i go up hill it bogs down like every other jeep ive had with 33 inch tires.
and trust me ive calculated this mpg evry fill up for the past 5k miles.
Newbie
Joined: Mar 2010
Posts: 27
Likes: 0
From: southwest NM
Year: 93
Model: Cherokee
Engine: 4 Bangger
I've been reading threads here and there about injector swaps... Why is this news, I don't know... But here's a quick run-down to answer some questions I've seen posted here.
Both Neon and Jeep injectors are high Z (impedance), 19lbs/hr injectors. Older Jeeps (not sure till what years) along with 95-99 model year neons ran an EV1, single hole injector. 00-05 Neons run on an EV6, four hole injector. All are rated at the same 19 lbs/hr.
My concern with those of you taking injectors out of 2nd Gen (00-05 neons), is the injector length. Yes, the plug is different, and that's an easy fix (just splice in new injector connector). But depending on which fuel rail/intake manifold combo you have on your Jeep, you may be setting yourself up for failure with the new, shorter, EV6 type injector from the 2nd Gen Neon.
That said, I've pulled some EV6 injectors out of a newer jeep. The injector was longer than Neon injectors; and to my surprise, it only had one hole.
So for those of us with older Jeeps (mine is a '89), be mindfull of the size of the new injector compared to your old one. It may not fit properly into the intake manifold if it's too short (and as stated before, you'll have to solder in an EV6 injector clip). Those of you with newer jeeps that already have EV6 injectors, you just have to worry about injector length with the neon injectors.
And I don't want to rant, but I'm also concerned about fuel pressure... 2nd Gen Neons run at a higher fuel pressure than older Jeeps. My ('89) Jeep runs at 31 psi. I believe my 2nd Gen Neons fuel pressure is something like 45 psi... Maybe even in the 50s. I'll look into it and report back.
Both Neon and Jeep injectors are high Z (impedance), 19lbs/hr injectors. Older Jeeps (not sure till what years) along with 95-99 model year neons ran an EV1, single hole injector. 00-05 Neons run on an EV6, four hole injector. All are rated at the same 19 lbs/hr.
My concern with those of you taking injectors out of 2nd Gen (00-05 neons), is the injector length. Yes, the plug is different, and that's an easy fix (just splice in new injector connector). But depending on which fuel rail/intake manifold combo you have on your Jeep, you may be setting yourself up for failure with the new, shorter, EV6 type injector from the 2nd Gen Neon.
That said, I've pulled some EV6 injectors out of a newer jeep. The injector was longer than Neon injectors; and to my surprise, it only had one hole.
So for those of us with older Jeeps (mine is a '89), be mindfull of the size of the new injector compared to your old one. It may not fit properly into the intake manifold if it's too short (and as stated before, you'll have to solder in an EV6 injector clip). Those of you with newer jeeps that already have EV6 injectors, you just have to worry about injector length with the neon injectors.
And I don't want to rant, but I'm also concerned about fuel pressure... 2nd Gen Neons run at a higher fuel pressure than older Jeeps. My ('89) Jeep runs at 31 psi. I believe my 2nd Gen Neons fuel pressure is something like 45 psi... Maybe even in the 50s. I'll look into it and report back.
Member
Joined: May 2009
Posts: 138
Likes: 0
From: NW PA
Year: 2000
Model: Cherokee
Engine: 4.0
Heat soak?
ie. Does it happen when the engine is stone cold? or just when it has been driven, left some minutes and stumbles on start up when warm?
As for re manufactured injectors, well .......yes. Personally I think that replacing 10 year old injectors that were not working right with 10 year old injectors from a wreck of unknown condition is asking for trouble.
Considering how much damage can be done by a faulty injector I think $150 for re manufactured injectors is very cheap insurance.
Or in your case you can get new or near new Ford XR3Z 9F593 A4B / XR3E 9F593 A4B (MOTORCRAFT #CM-4956 ) for around $60.
good luck with it.
ie. Does it happen when the engine is stone cold? or just when it has been driven, left some minutes and stumbles on start up when warm?
As for re manufactured injectors, well .......yes. Personally I think that replacing 10 year old injectors that were not working right with 10 year old injectors from a wreck of unknown condition is asking for trouble.
Considering how much damage can be done by a faulty injector I think $150 for re manufactured injectors is very cheap insurance.
Or in your case you can get new or near new Ford XR3Z 9F593 A4B / XR3E 9F593 A4B (MOTORCRAFT #CM-4956 ) for around $60.
good luck with it.
Member
Joined: Jun 2009
Posts: 150
Likes: 1
Model: Cherokee
No heat soak. Dead cold. after sitting over night. I bought them off the ebay guy. Allegedly passed an ohm test. May just buy the ford injectors after all. I was going to buy the new ford injectors, but a lot of guys said injectors from this guy worked out great for them. I think you were the one that actually told me the ford injectors were only 1 hole design, that's why I went for the 784's. Oh well at least it was only 35 bucks.
1) I would check fuel pressure on the fuel rail,
2) do 2000's have a inline fuel filter near the tank like the earlier models? if so i would replace that, after 10 years it is about due and only costs a few bucks.
On the "only" single hole ford injectors;
They(Ford XR3Z 9F593 A4B / XR3E 9F593 A4B ) do have 1 hole but do not confuse them with a pintal type injector / stock XJ injector .
-no it is not simple-
The EV6 method for increasing atomization was by increasing holes number and reducing each hole size. One can't add holes and reduce size indefinitely, so a new approach was needed when regulations became more strict.
The newer design single hole injectors do not relaying on number of holes, it's a completely different approach with the difference in the internal orifice which allow far better atomization. This allow even better ability to work on variable pressure, as with most newer car the pressure is computer controlled.
This, in turn, gives more accurate fuel mixture at any given pressure.
Last edited by rainman; Apr 26, 2010 at 05:04 AM.