Injector issue
08-19-2018, 08:28 PM
#1
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Model: Cherokee (XJ)
Injector issue
I have a 1990 jeep cherokee (5 speed, 4.0L) , i replaced the motor with a remand from oreillys. When i did we noticed the injectors were a little gunked up, so i went on amazon and got some new ones. Once i installed them my jeep ran like garbage. Three sets of injectors later and I’m still stuck. I put the stock injectors back in and boom, it runs about 80% i put in new injectors ( out of a Ford F-150 they are 21 pounds) and it runs like garbage, and i found out it’s from only two of the injectors firing when i put the new ones in (numbers 2 and 4). I even reset the pcm,and i refreshed all the grounds, and I’m still stumped. Any help is appreciated thanks!
08-19-2018, 09:16 PM
#3
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Year: 1994
Model: Cherokee (XJ)
Engine: 4.0 I6 H.O.
On my 94 i have only my code #27 going off. I realized the part number for my neon injectors are for the later year 4.0s according to the diagram i found on other threads. Have you checked your fuel pressure level with the injectors? I read some need a higher fuel pressure regulator. In some cases a high flow fuel pump will end up being needed over time if its on its last leg trying to keep up with the increased demand of fuel flow. Check the diagram see if the injectors match with what you need for that year. Try a fuel pressure test and find out what pressure level the engine is running at. At least this is my plan of action after i get the 703 injectors and get rid of the 749 neons i have now in my 94 high output 4.0, i hope this helps you!
08-19-2018, 09:58 PM
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Model: Cherokee (XJ)
On my 94 i have only my code #27 going off. I realized the part number for my neon injectors are for the later year 4.0s according to the diagram i found on other threads. Have you checked your fuel pressure level with the injectors? I read some need a higher fuel pressure regulator. In some cases a high flow fuel pump will end up being needed over time if its on its last leg trying to keep up with the increased demand of fuel flow. Check the diagram see if the injectors match with what you need for that year. Try a fuel pressure test and find out what pressure level the engine is running at. At least this is my plan of action after i get the 703 injectors and get rid of the 749 neons i have now in my 94 high output 4.0, i hope this helps you!
08-19-2018, 10:01 PM
#5
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it doesn’t run very well on 2 cylinders, it sorta coughs and stutters. I know it’s only two injectors because when i pull them out and turn the key, only two fire, then when i put them in the fuel holes and run it, i unplug them and it runs even worse, so only two are firing.
08-19-2018, 10:07 PM
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Year: 1994
Model: Cherokee (XJ)
Engine: 4.0 I6 H.O.
thats a good idea, I’ll check the fuel pressure tomorrow when i can get one from an auto parts store. Never thought maybe the pressure would be low, i had replaced the fuel pump about 4 months ago, but needing a bigger pump makes sense, hadn’t even thought of it thank you so much!
This is the diagram i have found.
08-20-2018, 12:45 AM
#7
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Model: Cherokee(XJ)
Engine: 4.0 Renix
it doesn’t run very well on 2 cylinders, it sorta coughs and stutters. I know it’s only two injectors because when i pull them out and turn the key, only two fire, then when i put them in the fuel holes and run it, i unplug them and it runs even worse, so only two are firing.
If only two of them were firing, and you unplugged them, there would be zero fuel getting to the engine and it absolutely could not run.
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08-20-2018, 07:50 AM
#8
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Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Get ahold of jnc7399 here on CF. He has the correct injectors.
On another note, is the ground spot at the engine dipstick tube stud clean and shiny with all the correct ground wires attached?
Is your distributor indexed correctly?
Links below.
http://cruiser54.com/?p=19
http://cruiser54.com/?p=68
On another note, is the ground spot at the engine dipstick tube stud clean and shiny with all the correct ground wires attached?
Is your distributor indexed correctly?
Links below.
http://cruiser54.com/?p=19
http://cruiser54.com/?p=68
08-20-2018, 12:04 PM
#9
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Model: Cherokee (XJ)
Get ahold of jnc7399 here on CF. He has the correct injectors.
On another note, is the ground spot at the engine dipstick tube stud clean and shiny with all the correct ground wires attached?
Is your distributor indexed correctly?
Links below.
http://cruiser54.com/?p=19
http://cruiser54.com/?p=68
On another note, is the ground spot at the engine dipstick tube stud clean and shiny with all the correct ground wires attached?
Is your distributor indexed correctly?
Links below.
http://cruiser54.com/?p=19
http://cruiser54.com/?p=68
08-21-2018, 01:39 AM
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Year: 1996
Model: Cherokee
Engine: 4.0L
Send the originals to Paul at http://hurstinjectorservice.com/ and he'll get them all cleaned up and re-done for you. Just had mine done last week actually.
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