Okay. I'm gonna try looking for answers here one last time before I head to a shop.
09-08-2015, 08:25 PM
#1
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Year: 1992
Model: Cherokee
Engine: 4.0l I6
Okay. I'm gonna try looking for answers here one last time before I head to a shop.
It's been 4 weeks now and I'm done. I'm either gonna take it to a shop or put a carb on it. Here's the break down...
92 Cherokee Laredo 4.0.
History...
Fully rebuilt the engine two months ago so the engine itself is fine.
One month ago I noticed a coolant leak from the bellhousing.
Removed tranny and saw bad freeze plug.
Replaced freeze plug, replaced tranny.
Noticed pinhole fuel leak in hose between fuel pump and fuel filter. Replaced hose and filter.
Problem...
Starts, idles, will NOT rev past 2k rpms. Just spits and pops and gasps.
What I think caused it...
I DID forget to unhook the battery when I started to remove the tranny and the starter arced against the frame.
What I did...
I have replaced the ECU, the crank position sensor, the o2 sensor, the ignition coil, the cap and rotor.
Getting spark out of all six wires.
Fuel pressure test shows 36 to 40 psi at all times.
I tested the TPS and it showed a volt range of .060 to .200. It is supposed to be .200 to 3.80ish.
Bought an Autozone TPS and it read the exact same voltages so I took it back.
Bought an O'Reilly TPS and it read the exact same voltages so I took it back.
While examining the wire harness a frayed wire to the TPS grounded against the manifold and caused the fuel pump to cycle.
I then fixed the frayed wire and now the (original) TPS reads perfect voltages. (.300 to 3.80ish).
Problem as of now...
Will NOT stay running when cold. I have to start it about 15 times before it holds a TERRIBLE clunky idle.
The idle gets better and better until it warms up and idles just fine, but it WILL NOT REV PAST IDLE.
It just clunks and pops out the intake and out the exhaust and acts like it is missing terribly but will NOT rev past 1000k to 1500k.
Stinks to high heaven. Plugs are all fouled.
Removed muffler and can see bright glowing red inside the catalytic converter.
What. In the hell. Do I do now? Please, ANY suggestions whatsoever I will try them all.
Thank you.
92 Cherokee Laredo 4.0.
History...
Fully rebuilt the engine two months ago so the engine itself is fine.
One month ago I noticed a coolant leak from the bellhousing.
Removed tranny and saw bad freeze plug.
Replaced freeze plug, replaced tranny.
Noticed pinhole fuel leak in hose between fuel pump and fuel filter. Replaced hose and filter.
Problem...
Starts, idles, will NOT rev past 2k rpms. Just spits and pops and gasps.
What I think caused it...
I DID forget to unhook the battery when I started to remove the tranny and the starter arced against the frame.
What I did...
I have replaced the ECU, the crank position sensor, the o2 sensor, the ignition coil, the cap and rotor.
Getting spark out of all six wires.
Fuel pressure test shows 36 to 40 psi at all times.
I tested the TPS and it showed a volt range of .060 to .200. It is supposed to be .200 to 3.80ish.
Bought an Autozone TPS and it read the exact same voltages so I took it back.
Bought an O'Reilly TPS and it read the exact same voltages so I took it back.
While examining the wire harness a frayed wire to the TPS grounded against the manifold and caused the fuel pump to cycle.
I then fixed the frayed wire and now the (original) TPS reads perfect voltages. (.300 to 3.80ish).
Problem as of now...
Will NOT stay running when cold. I have to start it about 15 times before it holds a TERRIBLE clunky idle.
The idle gets better and better until it warms up and idles just fine, but it WILL NOT REV PAST IDLE.
It just clunks and pops out the intake and out the exhaust and acts like it is missing terribly but will NOT rev past 1000k to 1500k.
Stinks to high heaven. Plugs are all fouled.
Removed muffler and can see bright glowing red inside the catalytic converter.
What. In the hell. Do I do now? Please, ANY suggestions whatsoever I will try them all.
Thank you.
Last edited by Zerocyde; 09-08-2015 at 08:30 PM.
09-08-2015, 08:30 PM
#2
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Well, your converter is bad for one, and that can cause some of the symptoms you're describing. Replace it and go from there, if necessary.
Last edited by 4WD4EVER; 09-08-2015 at 08:30 PM. Reason: Spelling
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09-08-2015, 08:35 PM
#3
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Year: 1992
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Also, I unbolted the entire exhaust from the exhaust manifold and ran it open header with the o2 sensor plugged in and it ran just the same.
09-08-2015, 08:41 PM
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Well, I believe a converter that is glowing red means it is plugged. You may have another issue(s), but that converter is ruined.
Edit: Any codes? You may have an ignition issue that's causing it to run rich. I would check my ignition system well and be sure it's firing correctly.
Edit: Any codes? You may have an ignition issue that's causing it to run rich. I would check my ignition system well and be sure it's firing correctly.
Last edited by 4WD4EVER; 09-08-2015 at 08:44 PM. Reason: Additional info
09-08-2015, 08:48 PM
#5
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Year: 1992
Model: Cherokee
Engine: 4.0l I6
At one point I got...
33 Air conditioning clutch relay circuit open or shorted
Then I got...
33 Air conditioning clutch relay circuit open or shorted
and
23 Incoming air temperature sensor may be bad
Then It was...
35 Cooling fan relay circuit open or shorted
Currently it is showing no codes.
33 Air conditioning clutch relay circuit open or shorted
Then I got...
33 Air conditioning clutch relay circuit open or shorted
and
23 Incoming air temperature sensor may be bad
Then It was...
35 Cooling fan relay circuit open or shorted
Currently it is showing no codes.
09-08-2015, 09:01 PM
#6
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Year: 1998
Engine: 4.0
You need to check the air temp sensor then. And the wiring in that circuit. I wouldn't replace the cat until you get the rest sorted out.
Honestly, if you're in over your head and you plan on keeping this rig, I'd recommend taking it to a skilled technician that has a solid reputation in your area and let him/her sort it out.
Honestly, if you're in over your head and you plan on keeping this rig, I'd recommend taking it to a skilled technician that has a solid reputation in your area and let him/her sort it out.
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09-08-2015, 09:17 PM
#9
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09-08-2015, 09:18 PM
#11
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Year: 1998
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This may help with the MAT sensor:
http://www.lunghd.com/Tech_Articles/...iagnostics.htm
09-08-2015, 09:34 PM
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Year: 2000
Model: Cherokee
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Okay. I'm gonna try looking for answers here one last time before I head to a shop.
Originally Posted by Zerocyde
Could pulling the tranny affect that?
It happened the FIRST time you started after the tranny? It might be smart to pull it again and see if you pinched wires in between the block and bell housing. Like they said. Wiring. O2 wires run that way, check all of them.
