Did the injector swap...and WOW!
CF Veteran
Joined: Mar 2010
Posts: 47,923
Likes: 38
From: Broward County Fl.
Year: 1989 xj sport 2dr
Model: Cherokee
Engine: 12 hole bosch Injectors
what? you can ad 7 injectors in an L6... all i know is that if you want to avoid running lean at WOT( if your showing off
) Then you gotta go with the MAP sensor mod... allows you to "manually" adjust fuel ratio.
http://www.angelfire.com/my/fan/MAP_adjuster.html
) Then you gotta go with the MAP sensor mod... allows you to "manually" adjust fuel ratio.http://www.angelfire.com/my/fan/MAP_adjuster.html
CF Veteran
Joined: Mar 2010
Posts: 47,923
Likes: 38
From: Broward County Fl.
Year: 1989 xj sport 2dr
Model: Cherokee
Engine: 12 hole bosch Injectors
I just spoke with http://www.mrinjector.us/ Bill.. I bought Filters and O rings for my stock units and for some used injectors Boche 784's that are on the way.. He told me for this style Intake spray pattern is not critical if not relevant at all. Thats why Jeep kept using these injectors that shoot gas like a water gun. Spray pattern is critical in OTHER applications but not on the 4 liter because, according to Bill, this style intake will put gas in a READY mode for use during driving and that gas can SIT inside the motor/ head/ cylynder until its used.. So spray patter is meaningless.. Somehting like this he told me.. Im no motor genius.. These guys have all the rebuild parts for the stock injectors. Anyway, I now have in my possession the fords stated here, I have 2 sets of stock injectors that will be refurbished to new, and I have a set of 784's that Im rebuilding with new rings, filters and caps, I will also be ordering the c4b's. When I am done I will have mileage specs on ALL 4 sets of injectors.. I will run two tanks out on each style to see what gas mileage I get.. When im done the results will be exacting.. Right now im lucky to get 15mpg with these fords Im running as stated in this thread. By the time Im done I will have spend hundreds of dollars to rebuild and buy injectors.. So much so i will begin to sell them off.. I even bought a Jewlry cleaner to clean the tips. lol.. All in the persuit of better gas mileage.. Im starting to spend so much on injectors that I wont make it up on gas..

Call him up! I am probably explaining it wrong but he said the way this motor fires is not critical for spray pattern.. Thats why almost EVERYONE sees no improvment in gas mileage with Boche or other brands.. These guys ONLY do injectors for a big business.. He was actually losing a sale by telling me that.. I was going to buy his 784's rebuilt from him..BUT instead I am going used for less just to try.. Im wasting my time since my stocks were A LOT better in power and gas once cleaned.. I took them out for jumpy idol.. I currently run XR3E9F593A4B brand new and stated as to be best ones for this application.. the gas mileage sucks.. my idle is crisp but that it.. similar to what everyone else reports. The only people seeing great results are the ones who NEVER CLEANED THE STOCK ONES TO BEGIN WITH!
All you have to do is buy a service kit for the Siemans Deka thats in the truck STOCK from this company and your good to go.. YOUR INJECTORS ARE DIRTY! changing to 4 hole is uselss. USE YOUR BRAIN! WHY DID CHRYSLER NOT GO 4 HOLE IN 2001?? NEONS WERE USING THEM THE SAME TIME THEY WERE PRODUCING JEEPS RIGHT? WOULDN'T THEY HAVE SAVED MILLIONS USING ONE KIND OF INJECTOR FOR JEEPS, NEONS AND CARAVANS?? CHRYLSER ENGINEERS ARE MORONS?? COMON!! INSTEAD THEY USED THESE STOCK INJECTORS BY SIEMANS DEKA ALL THE WAY TO 2004.. WHY DID THEY NOT RUN THE 784'S IN JEEPS FROM 2001 TO 2004 THEN?, DID YOU EVER ASK THAT QUESTION? THEY ARE NOT GOING TO MAKE A DIFFRENCE AND ILL PROVE IT IN MY LONG TEST OF ALL 4 STYLES.. I HOPE IM WRONG SINCE IM PAYING 320 PER GALLON NOW FOR GAS HERE IN NY!! IM GOING TO SELL THE JEEP IF I CAN'T GET IT TO 18MPG.. my best hope is the c4b's to improve gas which flow less. IM wasting my time but I will get the best set for my truck.. I could be wrong and I hope that the 784's work better! I doubt it though
All you have to do is buy a service kit for the Siemans Deka thats in the truck STOCK from this company and your good to go.. YOUR INJECTORS ARE DIRTY! changing to 4 hole is uselss. USE YOUR BRAIN! WHY DID CHRYSLER NOT GO 4 HOLE IN 2001?? NEONS WERE USING THEM THE SAME TIME THEY WERE PRODUCING JEEPS RIGHT? WOULDN'T THEY HAVE SAVED MILLIONS USING ONE KIND OF INJECTOR FOR JEEPS, NEONS AND CARAVANS?? CHRYLSER ENGINEERS ARE MORONS?? COMON!! INSTEAD THEY USED THESE STOCK INJECTORS BY SIEMANS DEKA ALL THE WAY TO 2004.. WHY DID THEY NOT RUN THE 784'S IN JEEPS FROM 2001 TO 2004 THEN?, DID YOU EVER ASK THAT QUESTION? THEY ARE NOT GOING TO MAKE A DIFFRENCE AND ILL PROVE IT IN MY LONG TEST OF ALL 4 STYLES.. I HOPE IM WRONG SINCE IM PAYING 320 PER GALLON NOW FOR GAS HERE IN NY!! IM GOING TO SELL THE JEEP IF I CAN'T GET IT TO 18MPG.. my best hope is the c4b's to improve gas which flow less. IM wasting my time but I will get the best set for my truck.. I could be wrong and I hope that the 784's work better! I doubt it though
Member
Joined: May 2010
Posts: 155
Likes: 0
From: Orono, Ontario
Year: 97
Model: Cherokee
Engine: 4.0L
I just spoke with http://www.mrinjector.us/ Bill.. I bought Filters and O rings for my stock units and for some used injectors Boche 784's that are on the way.. He told me for this style Intake spray pattern is not critical if not relevant at all. Thats why Jeep kept using these injectors that shoot gas like a water gun. Spray pattern is critical in OTHER applications but not on the 4 liter because, according to Bill, this style intake will put gas in a READY mode for use during driving and that gas can SIT inside the motor/ head/ cylynder until its used.. So spray patter is meaningless.
Gas does not sit inside the head or cylinder, ever. IF you have gas sitting inside the head or cylinder, you have flooded it.
Who ever told you that is dead wrong.
NEONS WERE USING THEM THE SAME TIME THEY WERE PRODUCING JEEPS RIGHT? WOULDN'T THEY HAVE SAVED MILLIONS USING ONE KIND OF INJECTOR FOR JEEPS, NEONS AND CARAVANS?? CHRYLSER ENGINEERS ARE MORONS?? COMON!! INSTEAD THEY USED THESE STOCK INJECTORS BY SIEMANS DEKA ALL THE WAY TO 2004.. WHY DID THEY NOT RUN THE 784'S IN JEEPS FROM 2001 TO 2004 THEN?, DID YOU EVER ASK THAT QUESTION?
IM GOING TO SELL THE JEEP IF I CAN'T GET IT TO 18MPG.. my best hope is the c4b's to improve gas which flow less. IM wasting my time but I will get the best set for my truck.. I could be wrong and I hope that the 784's work better! I doubt it though
That sounds crazy to me. Spray pattern is critical, no matter the application. If fuel sprayed out like a water pistol, it couldn't burn properly, period. Liquid gas has a hard time igniting. Gas vapor easily igniting`s, so what the injector does is take the liquid gas and forces it into a fine mist so it ignites.
Gas does not sit inside the head or cylinder, ever. IF you have gas sitting inside the head or cylinder, you have flooded it.
Who ever told you that is dead wrong.
Im no assembly line worker, or engineer, or whatnot, but i have family working at the local GM plant, and it takes a lot of downtime and money to make a mid production run change to a product because of the retooling and other changes. Also, to make a mid production run change like this, they would have test these changes. That equals more money for these lab and practical tests. That`s alot of money to shell out on a engine that cannot meet toughing emissions standards to begin with. That is also why Chrysler phased out the 4.0. It couldn`t keep up with the emissions. And they knew it.
These were never a fuel efficient engine, even more so in today's standards. You should have done some research before buying a vehicle. There are lots 4 cyl cars that are great on gas. I would look into it. Still, I wish you luck on your quest for better mileage. Just please, stop complaining about it. Every post i see about injectors and MPG, your there complaining. We get it.
Gas does not sit inside the head or cylinder, ever. IF you have gas sitting inside the head or cylinder, you have flooded it.
Who ever told you that is dead wrong.
Im no assembly line worker, or engineer, or whatnot, but i have family working at the local GM plant, and it takes a lot of downtime and money to make a mid production run change to a product because of the retooling and other changes. Also, to make a mid production run change like this, they would have test these changes. That equals more money for these lab and practical tests. That`s alot of money to shell out on a engine that cannot meet toughing emissions standards to begin with. That is also why Chrysler phased out the 4.0. It couldn`t keep up with the emissions. And they knew it.
These were never a fuel efficient engine, even more so in today's standards. You should have done some research before buying a vehicle. There are lots 4 cyl cars that are great on gas. I would look into it. Still, I wish you luck on your quest for better mileage. Just please, stop complaining about it. Every post i see about injectors and MPG, your there complaining. We get it.
Last edited by buysellny; Nov 17, 2010 at 11:43 PM.
Seasoned Member
Joined: Aug 2010
Posts: 358
Likes: 3
From: Illinois
Year: 1999
Model: Cherokee
Engine: 4.0
buysellny,
Your injector testing would be very interesting, but it sounds like you plan to change too many things to make it a very meaningful test. If you change your exhaust, air filter, throttle body, headers and add a Vortex air spinner(?) all at once, how will you know what is having an effect on fuel economy?
Please elaborate on the air spinner. I'm not familiar with that item.
Your injector testing would be very interesting, but it sounds like you plan to change too many things to make it a very meaningful test. If you change your exhaust, air filter, throttle body, headers and add a Vortex air spinner(?) all at once, how will you know what is having an effect on fuel economy?
Please elaborate on the air spinner. I'm not familiar with that item.
Member
Joined: May 2010
Posts: 155
Likes: 0
From: Orono, Ontario
Year: 97
Model: Cherokee
Engine: 4.0L
However, Im more pissed as I filled up and went from 15mpg now to 13mpg? This is the last time I will mention injectors.. Im putting stock ones back in rebuilt and end of it.. Todays fillup was unexpected.. Mileage is going down.. Im pissed because changing injectors was not worth it in my opinion.
can someone tell me where to find these invisble two other o2 sensors on a 4.0?
Senior Member
Joined: Feb 2010
Posts: 681
Likes: 1
From: errrvre where
Year: 1996
Model: Cherokee
Engine: I6 4.0L HO, JBA headers, 99 intake, #703 injectors
[QUOTE=jeans;739824]Did you reset the computer after changing them? And after you reset the computer, the ECU has to relearn its fuel trims. That takes 50 key cycles(That dosent mean turning the key 50 times on and off back to back. 50 trips). After i did my 703 swap, my mileage went down before i saw improvements.
how did you reset your ecu? just start it 50 times? or just over time of starting it you saw your mpg go up?
how did you reset your ecu? just start it 50 times? or just over time of starting it you saw your mpg go up?
[QUOTE=Allusion;739889]
I stuck the positive and negative together for 1/2 hour and did the light and key sequence as well.. Today I cleaned out the vaume hose from the intake manifild to the valve cover.. Clogged to hell! I could not even blow air through it. Now its cleaned out with a wire.. I wish i could get the grommet off the valve cover but that thing is like ON!
Did you reset the computer after changing them? And after you reset the computer, the ECU has to relearn its fuel trims. That takes 50 key cycles(That dosent mean turning the key 50 times on and off back to back. 50 trips). After i did my 703 swap, my mileage went down before i saw improvements.
how did you reset your ecu? just start it 50 times? or just over time of starting it you saw your mpg go up?
how did you reset your ecu? just start it 50 times? or just over time of starting it you saw your mpg go up?
buysellny,
Your injector testing would be very interesting, but it sounds like you plan to change too many things to make it a very meaningful test. If you change your exhaust, air filter, throttle body, headers and add a Vortex air spinner(?) all at once, how will you know what is having an effect on fuel economy?
Please elaborate on the air spinner. I'm not familiar with that item.
Your injector testing would be very interesting, but it sounds like you plan to change too many things to make it a very meaningful test. If you change your exhaust, air filter, throttle body, headers and add a Vortex air spinner(?) all at once, how will you know what is having an effect on fuel economy?
Please elaborate on the air spinner. I'm not familiar with that item.
CF Veteran
Joined: Jan 2009
Posts: 1,964
Likes: 6
From: Baltimore, Maryland
Year: 1994 1993
Model: Cherokee
Engine: 4.0
....THEY ARE NOT GOING TO MAKE A DIFFRENCE AND ILL PROVE IT IN MY LONG TEST OF ALL 4 STYLES.. I HOPE IM WRONG SINCE IM PAYING 320 PER GALLON NOW FOR GAS HERE IN NY!! IM GOING TO SELL THE JEEP IF I CAN'T GET IT TO 18MPG.. my best hope is the c4b's to improve gas which flow less. IM wasting my time but I will get the best set for my truck.. I could be wrong and I hope that the 784's work better! I doubt it though
Oy! For about the 5th time..You arent going to see much of a MPG change no matter which of the "upgrade" injectors you use. Maybe 1-2 MPG. That`s not really the point of the upgrade. So people do see a noticable increase in MPG simply because their old injectors were probably fouled up. The main reasons for doing the upgrade are for a better engine performance and throttle response. As for your test, I have personally run stock XJ injectors that have been completely rebuilt..703 Neons with both the 39 psi and 49 psi fuel pressure regulator..Ford 710 "yellow stick" injectors again with both FPR's..Ford "blue stick" 715's and the earliest Neon EV 1.3 4-port injectors. Right now I am getting near 21 MPG highway in my 1994 XJ with 210,000 miles on it. Maybe 15 MPG city. That`s about it. I can understand your frustration with the MPG and gas prices but if that is your main concern I would suggest dumping your Jeep for something better on gas.
i'm doing this next week. thank God I already have a good block and head that breathes better, plus borla, '01 intake, and 62mm TB. I should be able to pull a solid 20mpg from mine.


