Better MPG?
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From: City of Trees, CA
Year: 93 2 door
Model: Cherokee
Engine: 4.0
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From: Miami
Year: 1995
Model: Cherokee
Engine: 4.0 HO
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Joined: Jan 2011
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From: Eh infusion
Year: 2000
Model: Cherokee
Engine: The legendary inline 6, haven't done anything here yet
Originally Posted by Atmos
and the other 50% say there was no noticeable difference
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Joined: Apr 2012
Posts: 1,666
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From: Miami
Year: 1995
Model: Cherokee
Engine: 4.0 HO
picked mine up from the jy. cleaned them, waiting on o-ring kit. then swap them. if it rides rough then you need to restart something(dont remember what it was). but yea, its pretty straight foward
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Joined: Jan 2011
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From: Eh infusion
Year: 2000
Model: Cherokee
Engine: The legendary inline 6, haven't done anything here yet
Originally Posted by GreyDog
There is a thread near the top in OEMcherokee that goes pretty indepth about the injectors. Seems like it isn't quite as simple as swap n go.
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Joined: Apr 2012
Posts: 202
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From: VA
Year: 1999
Model: Cherokee
Engine: 4.0L I6
No, I mean I know the swap is simple. And you need to restart your computer by draining the charge (either diconnect the bat and leave the lights on or touch the terminals or whatever).
What I am saying is that to gain performance, especially mpgs, it seems that more needs to be done, especially with the 703s out of a neon. Just read the thread, I am way out of my depth trying to explain it.
What I am saying is that to gain performance, especially mpgs, it seems that more needs to be done, especially with the 703s out of a neon. Just read the thread, I am way out of my depth trying to explain it.
CF Veteran
Joined: Jan 2011
Posts: 1,245
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From: Lexington, KY
Year: 1997
Model: Cherokee
Engine: 4.0 HO with a bored throttle body and 703 injectors
What about a reusable air filter? I got my Specter filter for less then $20, and if it hadn't helped mpg I would still save from washing and reusing it instead of buy a new paper filter every time it needs one.
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Joined: Apr 2012
Posts: 1,666
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From: Miami
Year: 1995
Model: Cherokee
Engine: 4.0 HO
No, I mean I know the swap is simple. And you need to restart your computer by draining the charge (either diconnect the bat and leave the lights on or touch the terminals or whatever).
What I am saying is that to gain performance, especially mpgs, it seems that more needs to be done, especially with the 703s out of a neon. Just read the thread, I am way out of my depth trying to explain it.
What I am saying is that to gain performance, especially mpgs, it seems that more needs to be done, especially with the 703s out of a neon. Just read the thread, I am way out of my depth trying to explain it.
CF Veteran
Joined: Jan 2011
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From: Lexington, KY
Year: 1997
Model: Cherokee
Engine: 4.0 HO with a bored throttle body and 703 injectors
Originally Posted by GreyDog
The 3.7L v6 Liberty injectors are supposed to be better, so yeah, CherokeeChick is right about that.
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From: Long Beach, Ca
Year: 2000
Model: Cherokee
Engine: 4.0 I6
I've got 784 injectors, spectre high flow intake filter, brand new spark plugs, magnaflow performance muffler, 2.5" pipe, and sitting on 235/75 ATs and I'm only getting about 20mpg. I'm happy with it but there haven't been any gains from the mods I've done.
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Joined: Apr 2012
Posts: 202
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From: VA
Year: 1999
Model: Cherokee
Engine: 4.0L I6
The actual flow rating of the injectors is typically 85% of what I measured. If you swap to the 703 Neon injectors you will be able to flow about 20% more fuel than stock. This is a plus if you can pump 20% more air through your engine. If not, or you are more interested in gas mileage, then there is an additional problem with the 703s (and 784s based on supplier data).
The dynamic flow rate of the Neon injectors is 50% higher than stock. This means that the amount of fuel that is sprayed for a given injector on pulse is 1.5 times greater than a stock injector. Sure, you can reset your ECU so it “learns” how much fuel to spray for the engine conditions, but it can only do so much. Ever try to get one drop of water out of a faucet? How about a fire hydrant? Good luck. The ECU can only compute the amount of desired on time to so many milliseconds and then it rounds up or down. The injector components can only respond so fast to the signals sent to it. To get fine metering of fuel, you need a low dynamic flow rate.
I found a better set of injectors to use on my Jeep. They came out of a Jeep Liberty 3.7liter V6. They use the same connector style as the 784s Neon and stock injectors used in newer model 4.0 liter Cherokees, have the 4 spray holes, and are EV14 which is a generation newer than the EV6 703 and 784 injectors. They flow tested at 21.1 lb/hr (2.7%) higher than stock, with a dynamic flow only 24% higher than stock. They did require that I change the connectors out, but it was worth it. I have not been able to find a better match to the stock injectors than this.
I put them in without resetting the ECU and never looked back. Fuel mileage is 10% better than stock based on 12 fill-ups and 3400 miles of driving. The throttle response is definitely improved, and fuel metering is much better. Here is what I consider the best testament to how smoothly these run. Once my Jeep is warmed up and on level ground, I can slip the clutch and slowly shift through all 5 gears without ever touching the gas. 234,000 miles, 4WD, 235/75/15 tires, stock gears, 100 lbs of gear in the back, tank empty or full, 750 RPM idle going 25 MPH without chugging or bucking. Before the swap, it would start chugging in third.
The dynamic flow rate of the Neon injectors is 50% higher than stock. This means that the amount of fuel that is sprayed for a given injector on pulse is 1.5 times greater than a stock injector. Sure, you can reset your ECU so it “learns” how much fuel to spray for the engine conditions, but it can only do so much. Ever try to get one drop of water out of a faucet? How about a fire hydrant? Good luck. The ECU can only compute the amount of desired on time to so many milliseconds and then it rounds up or down. The injector components can only respond so fast to the signals sent to it. To get fine metering of fuel, you need a low dynamic flow rate.
I found a better set of injectors to use on my Jeep. They came out of a Jeep Liberty 3.7liter V6. They use the same connector style as the 784s Neon and stock injectors used in newer model 4.0 liter Cherokees, have the 4 spray holes, and are EV14 which is a generation newer than the EV6 703 and 784 injectors. They flow tested at 21.1 lb/hr (2.7%) higher than stock, with a dynamic flow only 24% higher than stock. They did require that I change the connectors out, but it was worth it. I have not been able to find a better match to the stock injectors than this.
I put them in without resetting the ECU and never looked back. Fuel mileage is 10% better than stock based on 12 fill-ups and 3400 miles of driving. The throttle response is definitely improved, and fuel metering is much better. Here is what I consider the best testament to how smoothly these run. Once my Jeep is warmed up and on level ground, I can slip the clutch and slowly shift through all 5 gears without ever touching the gas. 234,000 miles, 4WD, 235/75/15 tires, stock gears, 100 lbs of gear in the back, tank empty or full, 750 RPM idle going 25 MPH without chugging or bucking. Before the swap, it would start chugging in third.
First couple paragraphs explain the difference between stock and 703s or 784s and the last two explain why the Liberty injectors are better.
None of this is my own finding, but rather notop46 did the work and shared with all of us.
CF Veteran
Joined: Jan 2011
Posts: 8,998
Likes: 3
From: Eh infusion
Year: 2000
Model: Cherokee
Engine: The legendary inline 6, haven't done anything here yet
Originally Posted by GreyDog
No, I mean I know the swap is simple. And you need to restart your computer by draining the charge (either diconnect the bat and leave the lights on or touch the terminals or whatever).
What I am saying is that to gain performance, especially mpgs, it seems that more needs to be done, especially with the 703s out of a neon. Just read the thread, I am way out of my depth trying to explain it.
What I am saying is that to gain performance, especially mpgs, it seems that more needs to be done, especially with the 703s out of a neon. Just read the thread, I am way out of my depth trying to explain it.