need some help here
08-08-2009, 11:10 AM
#1
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Model: Cherokee
need some help here
I did a 4.0 swap on my 1994 xj. I have everything in it. I got the engine to run. Here is the thing. It doesn't like to idle well nor do I have throttle responce. I have pulled my plugs. It's showing me that my fule mix is bad. Well here is the thing. I got a computer from the junk yard. I don't think it is from a HO. I think I have come to realize that there is a different computer for the HO but not sure. The mapping should be different for the fule air mix. Not sure of this. I'm running out of time to get it up and running. I this is my everyday driver. Getting the kids back in weeks. So I need to get them around. Pluss sick of bumming rides and biking every where..........
steve
steve
08-08-2009, 01:05 PM
#3
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Well I forget what year thwe jeep I took the ecm out of. I knoew it was the same generation as mine... also it is odb1 computer. Almost possative the computer I have is a non ho one. I have been doing some resurch. I found there is 3 different computers for my jeep. Yes I did tell the parts store it was a 5 speed.... with fed admissions. I don't have the 2nd o2 sensor for her. Nor am I showing a code for it.....
08-08-2009, 01:06 PM
#4
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Year: 1990XJ/1989MJ
Model: Comanche
Engine: 4.0L Renix
Here is the ECU breakdown.
87-90 used 2 computers one for Auto and one for Manuals
91-95 used an OBD I computer but it consoladated trannys.
96-99 used an OBD II computer
00-on used a different ECU.
Hope that helps you solve your problems.
87-90 used 2 computers one for Auto and one for Manuals
91-95 used an OBD I computer but it consoladated trannys.
96-99 used an OBD II computer
00-on used a different ECU.
Hope that helps you solve your problems.
08-08-2009, 01:23 PM
#5
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Year: 89
Model: Cherokee
Engine: 4.0
Well I forget what year thwe jeep I took the ecm out of. I knoew it was the same generation as mine... also it is odb1 computer. Almost possative the computer I have is a non ho one. I have been doing some resurch. I found there is 3 different computers for my jeep. Yes I did tell the parts store it was a 5 speed.... with fed admissions. I don't have the 2nd o2 sensor for her. Nor am I showing a code for it.....
08-09-2009, 12:55 AM
#6
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Year: 1994
Model: Cherokee
Engine: 4.0L I6
Great info here. Had a similar question and I think it is answered.. Will describe my problem for a second opinion.
Have 1994 Jeep Cherokee. Have not driven in a little over a year due to some needed maintenance and repairs, but started it frequently to as recently as 3 months ago.
Just tried to get it started to no avail. Used starting fluid and the engine would run as long as I kept spraying starting fluid. First checked pulse at fuel injectors with multimeter and saw a pulse (too quick to determine voltage of pulse). Disconnected fuel line and fuel rail was pressurized. Took off fuel rail and checked that injectors weren't clogged. Checked pressure of fuel rail which peaked at 50psi. Changed fuel pump pressure reached 95 psi, still wont start. Drained old gas (was about 9 months old) and replaced with 5 gallons of 93 octane. Replaced crank shaft and cam shaft sensors still wont work. Verified good coil and spark plugs (even though I knew they were working based on firing on starting fluid). No error codes were registering on computer. Poured a cup of gas down the throttle body... flooded the motor and had to pull the plugs. Evacuated the cylinders using a vacuum cleaner (to get the air moving through to help the evaporation process). Replaced spark plugs and was able to run again on starting fluid.
Then I took it to a mechanic told them all I had done. They retried several of my troubleshooting steps. Then hooked the Jeep to a diagnostic computer which said that there was no injector pulse. They also got a similar pulse as I did using a multimeter, but apparently it was not enough to register on the diagnostic computer???
To make this long story even longer they figured the ECM needed replacing, and were looking to order a new one or a rebuild quoting $300 for the part. I went to the U-Pull-It today and found an ECM from a 1991 Jeep Cherokee Laredo 4.0L Automatic transmission and was wondering if I could just swap it in place of my current ECM. Serial on my 1994 ECM is 56027 889. Serial number on the ECM I pulled today is 56005 707. I would put the ECM in today if I could but mechanics dont get back until monday and my car is locked in their garage.
Based on BlueXJ's and Mixed89's posts it appears that I can.
What do you guys think?
Have 1994 Jeep Cherokee. Have not driven in a little over a year due to some needed maintenance and repairs, but started it frequently to as recently as 3 months ago.
Just tried to get it started to no avail. Used starting fluid and the engine would run as long as I kept spraying starting fluid. First checked pulse at fuel injectors with multimeter and saw a pulse (too quick to determine voltage of pulse). Disconnected fuel line and fuel rail was pressurized. Took off fuel rail and checked that injectors weren't clogged. Checked pressure of fuel rail which peaked at 50psi. Changed fuel pump pressure reached 95 psi, still wont start. Drained old gas (was about 9 months old) and replaced with 5 gallons of 93 octane. Replaced crank shaft and cam shaft sensors still wont work. Verified good coil and spark plugs (even though I knew they were working based on firing on starting fluid). No error codes were registering on computer. Poured a cup of gas down the throttle body... flooded the motor and had to pull the plugs. Evacuated the cylinders using a vacuum cleaner (to get the air moving through to help the evaporation process). Replaced spark plugs and was able to run again on starting fluid.
Then I took it to a mechanic told them all I had done. They retried several of my troubleshooting steps. Then hooked the Jeep to a diagnostic computer which said that there was no injector pulse. They also got a similar pulse as I did using a multimeter, but apparently it was not enough to register on the diagnostic computer???
To make this long story even longer they figured the ECM needed replacing, and were looking to order a new one or a rebuild quoting $300 for the part. I went to the U-Pull-It today and found an ECM from a 1991 Jeep Cherokee Laredo 4.0L Automatic transmission and was wondering if I could just swap it in place of my current ECM. Serial on my 1994 ECM is 56027 889. Serial number on the ECM I pulled today is 56005 707. I would put the ECM in today if I could but mechanics dont get back until monday and my car is locked in their garage.
Based on BlueXJ's and Mixed89's posts it appears that I can.
What do you guys think?
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08-09-2009, 12:49 PM
#8
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Year: 89
Model: Cherokee
Engine: 4.0
Great info here. Had a similar question and I think it is answered.. Will describe my problem for a second opinion.
Have 1994 Jeep Cherokee. Have not driven in a little over a year due to some needed maintenance and repairs, but started it frequently to as recently as 3 months ago.
Just tried to get it started to no avail. Used starting fluid and the engine would run as long as I kept spraying starting fluid. First checked pulse at fuel injectors with multimeter and saw a pulse (too quick to determine voltage of pulse). Disconnected fuel line and fuel rail was pressurized. Took off fuel rail and checked that injectors weren't clogged. Checked pressure of fuel rail which peaked at 50psi. Changed fuel pump pressure reached 95 psi, still wont start. Drained old gas (was about 9 months old) and replaced with 5 gallons of 93 octane. Replaced crank shaft and cam shaft sensors still wont work. Verified good coil and spark plugs (even though I knew they were working based on firing on starting fluid). No error codes were registering on computer. Poured a cup of gas down the throttle body... flooded the motor and had to pull the plugs. Evacuated the cylinders using a vacuum cleaner (to get the air moving through to help the evaporation process). Replaced spark plugs and was able to run again on starting fluid.
Then I took it to a mechanic told them all I had done. They retried several of my troubleshooting steps. Then hooked the Jeep to a diagnostic computer which said that there was no injector pulse. They also got a similar pulse as I did using a multimeter, but apparently it was not enough to register on the diagnostic computer???
To make this long story even longer they figured the ECM needed replacing, and were looking to order a new one or a rebuild quoting $300 for the part. I went to the U-Pull-It today and found an ECM from a 1991 Jeep Cherokee Laredo 4.0L Automatic transmission and was wondering if I could just swap it in place of my current ECM. Serial on my 1994 ECM is 56027 889. Serial number on the ECM I pulled today is 56005 707. I would put the ECM in today if I could but mechanics dont get back until monday and my car is locked in their garage.
Based on BlueXJ's and Mixed89's posts it appears that I can.
What do you guys think?
Have 1994 Jeep Cherokee. Have not driven in a little over a year due to some needed maintenance and repairs, but started it frequently to as recently as 3 months ago.
Just tried to get it started to no avail. Used starting fluid and the engine would run as long as I kept spraying starting fluid. First checked pulse at fuel injectors with multimeter and saw a pulse (too quick to determine voltage of pulse). Disconnected fuel line and fuel rail was pressurized. Took off fuel rail and checked that injectors weren't clogged. Checked pressure of fuel rail which peaked at 50psi. Changed fuel pump pressure reached 95 psi, still wont start. Drained old gas (was about 9 months old) and replaced with 5 gallons of 93 octane. Replaced crank shaft and cam shaft sensors still wont work. Verified good coil and spark plugs (even though I knew they were working based on firing on starting fluid). No error codes were registering on computer. Poured a cup of gas down the throttle body... flooded the motor and had to pull the plugs. Evacuated the cylinders using a vacuum cleaner (to get the air moving through to help the evaporation process). Replaced spark plugs and was able to run again on starting fluid.
Then I took it to a mechanic told them all I had done. They retried several of my troubleshooting steps. Then hooked the Jeep to a diagnostic computer which said that there was no injector pulse. They also got a similar pulse as I did using a multimeter, but apparently it was not enough to register on the diagnostic computer???
To make this long story even longer they figured the ECM needed replacing, and were looking to order a new one or a rebuild quoting $300 for the part. I went to the U-Pull-It today and found an ECM from a 1991 Jeep Cherokee Laredo 4.0L Automatic transmission and was wondering if I could just swap it in place of my current ECM. Serial on my 1994 ECM is 56027 889. Serial number on the ECM I pulled today is 56005 707. I would put the ECM in today if I could but mechanics dont get back until monday and my car is locked in their garage.
Based on BlueXJ's and Mixed89's posts it appears that I can.
What do you guys think?
08-10-2009, 12:40 AM
#9
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Year: 1994
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Engine: 4.0L I6
Thanks Mixed 89... makes me feel better. Will try tommorrow when shop opens and hopefully my problem will be solved.
Thanks for the info you posted.. very helpful.
Thanks for the info you posted.. very helpful.
08-10-2009, 01:05 PM
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Year: 1994
Model: Cherokee
Engine: 4.0L I6
Just replaced my ECM from a 1991 Jeep Cherokee Laredo 4.0L into MY 1994 Jeep Cherokee Sport 4.0L. Now cannot get started due to anti-theft immobilizer.... I have no idea how to begin to troubleshoot this. I only have the 1 original key, there is no chip on my key... Ive locked and unlocked both doors (opened and shut). Locked/unlocked tailgate also opened and shut several times.... opened and shut hood several times... is there a way around this?
HELP!
HELP!