1987 Jeep Cherokee
#1
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Model: Cherokee
1987 Jeep Cherokee
Please help me of you can. I have a 1987 Jeep Cherokee with 4.0 and fuel injected that has what I値l say is a bad misfire at higher speeds. It starts and runs fine if I知 running in town and off road at slow speed/RPMs it's fine. If it痴 in 3rd gear and I知 running at 50 mph it will start missing, meaning it has a bad jerk. If it痴 in overdrive it won稚 start until 60 to 65 mph and the faster you go the worse it gets. In both cases it will only miss/jerk if I知 maintain my speed, if I知 accelerating or if I let off the gas it runs fine, smooth with no missing or jerking.
I have read as lot of postings but most don稚 seem to relate to my problem. I have replaces the distributer cap and rotor, plugs and plug wires. My crank shaft poison sensor went out and I replace it. Even wander if I got a bad one I replaced it a second time. No luck
I took it to local transmission shop thinking it could be in the tranny, the guy took it on a 15 mile drive at low speeds and highway speeds and said he thinks the tranny is fine. He suggested that I replace the distributer. Thinking if the bearing or lower gear was ware it could have play or slop when it was NOT under acceleration. Just though I would check to see if other have had this problem before taking this as my next step.
If you have heard of this, what was your cure?
I have read as lot of postings but most don稚 seem to relate to my problem. I have replaces the distributer cap and rotor, plugs and plug wires. My crank shaft poison sensor went out and I replace it. Even wander if I got a bad one I replaced it a second time. No luck
I took it to local transmission shop thinking it could be in the tranny, the guy took it on a 15 mile drive at low speeds and highway speeds and said he thinks the tranny is fine. He suggested that I replace the distributer. Thinking if the bearing or lower gear was ware it could have play or slop when it was NOT under acceleration. Just though I would check to see if other have had this problem before taking this as my next step.
If you have heard of this, what was your cure?
#2
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Year: 1987
Model: Cherokee
Engine: I6
I would go through testing all sensors on the motor before I put money into anything. Sometimes it just needs some TLC and adjustment and you're up and running again.
Use this link to run through all sensor testing:
http://www.lunghd.com/Tech_Articles/...iagnostics.htm
Mine ran like a three legged dog when I got it and without any money I was able to get her running strong.
Use this link to run through all sensor testing:
http://www.lunghd.com/Tech_Articles/...iagnostics.htm
Mine ran like a three legged dog when I got it and without any money I was able to get her running strong.
#3
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Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
Start with new plugs, wires, cap and rotor.
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Year: 1990
Model: Cherokee
Engine: 4.0
Originally Posted by cruiser54
Start with new plugs, wires, cap and rotor.
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I would go through testing all sensors on the motor before I put money into anything. Sometimes it just needs some TLC and adjustment and you're up and running again.
Use this link to run through all sensor testing:
http://www.lunghd.com/Tech_Articles/...iagnostics.htm
Mine ran like a three legged dog when I got it and without any money I was able to get her running strong.
Use this link to run through all sensor testing:
http://www.lunghd.com/Tech_Articles/...iagnostics.htm
Mine ran like a three legged dog when I got it and without any money I was able to get her running strong.
Most of all I like doing it without spending any money.
#6
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Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
A nearly complete set of write-ups I've done on Renix Jeeps can be found at the attached link under Help and Resources. Most all of them require only time and effort and no money. I do think, however, you should spring for tune-up parts first.
www.jeepseekers.com
www.jeepseekers.com
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Model: Cherokee
1987 Jeep Cherokee
I wanted to thank you for the information, I know I知 slow at letting you know what I found but I知 trying to make sure I do my test correctly. I have found two things that didn稚 test correct. The Manifold Absolute Pressure Sensor (MAP), I get the 5 volts on the supply terminal C but I can稚 get anything from terminal B. Not sure if I should replace it or test for something else? I知 going to do some more reading on this.
I also found that the Throttle Position Sensor (TPS) was not working, I adjusted It and it helped take away the missing when running in overdrive but it still happen when I知 in 3 gear, seems to start around 40 mph.
I think I知 going to repeat all the test to make sure I have not overlooked something.
Let me know if anything else comes to mind
Thank you for your help
//////////////////////////////////////////////////////////////////////////////////
I also found that the Throttle Position Sensor (TPS) was not working, I adjusted It and it helped take away the missing when running in overdrive but it still happen when I知 in 3 gear, seems to start around 40 mph.
I think I知 going to repeat all the test to make sure I have not overlooked something.
Let me know if anything else comes to mind
Thank you for your help
//////////////////////////////////////////////////////////////////////////////////
I would go through testing all sensors on the motor before I put money into anything. Sometimes it just needs some TLC and adjustment and you're up and running again.
Use this link to run through all sensor testing:
http://www.lunghd.com/Tech_Articles/...iagnostics.htm
Mine ran like a three legged dog when I got it and without any money I was able to get her running strong.
Use this link to run through all sensor testing:
http://www.lunghd.com/Tech_Articles/...iagnostics.htm
Mine ran like a three legged dog when I got it and without any money I was able to get her running strong.
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#8
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Year: 1990
Model: Cherokee (XJ)
Engine: 4.0
I wanted to thank you for the information, I know I知 slow at letting you know what I found but I知 trying to make sure I do my test correctly. I have found two things that didn稚 test correct. The Manifold Absolute Pressure Sensor (MAP), I get the 5 volts on the supply terminal C but I can稚 get anything from terminal B. Not sure if I should replace it or test for something else? I知 going to do some more reading on this.
I also found that the Throttle Position Sensor (TPS) was not working, I adjusted It and it helped take away the missing when running in overdrive but it still happen when I知 in 3 gear, seems to start around 40 mph.
I think I知 going to repeat all the test to make sure I have not overlooked something.
Let me know if anything else comes to mind
Thank you for your help
//////////////////////////////////////////////////////////////////////////////////
I also found that the Throttle Position Sensor (TPS) was not working, I adjusted It and it helped take away the missing when running in overdrive but it still happen when I知 in 3 gear, seems to start around 40 mph.
I think I知 going to repeat all the test to make sure I have not overlooked something.
Let me know if anything else comes to mind
Thank you for your help
//////////////////////////////////////////////////////////////////////////////////
Revised 04-18-2012
* means instructions have been written.
1-Ground refreshing, adding engine bay grounds, link to Kelleys WIP*
1a-Improving the instrument panel ground*
2- Checking sensor grounds*
2a- Repairing sensor grounds*
3-C101 Connector Refreshing*
4-Connector and relay /receptacle refreshing*
5-Coil/ICM contacts*
6- Snugging up intake manifold bolts
7-Throttle body and IAC cleaning
8-TPS testing and adjusting*
9-CPS testing and adjusting*
10-CPS wiring bypass
11-ECU connector refreshing
12-Distributor indexing
13-O2 sensor diagnostics
14-Setting base idle
15-Valve cover mod*
16-Sensor ground upgrade*
17-CPS Timing Advance Mod*
18-Headlight Harness Installation*
19-Trans Plug Connector Refreshing*
20- Rear Main Seal Diagnosis*
21-Vacuum Test For Exhaust Restriction*
22-Restoring Throttle Butterfly Adjustment
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