Bogger45 Posted June 11, 2016 Share Posted June 11, 2016 1992 Jeep Comanche 4.0 High output model Here's the story: My Comanche ran fine all winter. I had to let it sit for 2 months came back and everything seemed fine. Ones the truck got around 100f in the summer weather it starts running like garbage. It will not rev over 2 rpm starts sputtering back firing abd zero power it even effects the charging system and makes the battery gauge drop and the system does not appear to charge the battery. The truck runs fine as long as it cools down and I try to crank it again. I've replaced plugs and wires, checked for vacuum leaks, took the exhaust off to see if it was the catalytic converter, and cleaned the throttle body . None of this worked. I recorded a video of it warm and you can see and hear what's going on https://youtu.be/f4X9cvsPvmo Guys in a real jam here just can't figure this out. Link to comment Share on other sites More sharing options...
rustybottoms88 Posted June 11, 2016 Share Posted June 11, 2016 I couldnt tell a whole lot from the video. Might consider the coil too. Might be getting old and weak, through in some heat and it is about done for. Link to comment Share on other sites More sharing options...
HOrnbrod Posted June 11, 2016 Share Posted June 11, 2016 Check for fault codes. http://comancheclub.com/topic/28111-reading-obdi-91-and-92-mj-fault-codes/ Link to comment Share on other sites More sharing options...
Bogger45 Posted June 11, 2016 Author Share Posted June 11, 2016 Getting codes 12, 22, 23, 24,14, and end of codes 55.gonna replace the TPS. Link to comment Share on other sites More sharing options...
HOrnbrod Posted June 11, 2016 Share Posted June 11, 2016 Sounds like you are not going fully into closed loop operation, i.e.staying in open mode. Plus it looks like you have a CEL. My first suspect would be the O2 sensor. Either it's bad or the harness got fried by the exhaust manifold or pipe. I had a bad O2 sensor once with no code 21. Link to comment Share on other sites More sharing options...
Bogger45 Posted June 11, 2016 Author Share Posted June 11, 2016 New TPS new oxygen sensor new map sensor new coil...still bogging down when I mash the throttle. Link to comment Share on other sites More sharing options...
HOrnbrod Posted June 11, 2016 Share Posted June 11, 2016 Get rid of the codes and clean out the memory and using the below procedure to start the ECM from scratch. It should help: Clearing error codes and removing residual memory1. Disconnect the POSITIVE battery Terminal and touch it to ground for 30 seconds. (This is to discharge the PCM capacitors, which maintain the Adaptive Memory.2. Reconnect the Positive Battery Cable3. Turn Ignition Switch to the "ON" position but DO NOT start the engine4. Turn Headlight "ON"5. Turn Headlights "OFF"6. Turn Ignition Key "OFF"The PCM Adaptive memory has now been flashed, or erased from the PCM. Link to comment Share on other sites More sharing options...
Bogger45 Posted June 12, 2016 Author Share Posted June 12, 2016 Cleared restarted. Let it warm up failed again sputtering codes 12,22,23,24,14, 55 end of codes. Guys I don't know if this helps but it ran fine this evening in the cool air until the engined w armed up. During noon however it ran bad all day, with zero recovery until the weather cooled down Link to comment Share on other sites More sharing options...
Bogger45 Posted June 12, 2016 Author Share Posted June 12, 2016 Are there any components inside the dash that could cause such issue...just seems weird it gets warm and it will run bad all day? Link to comment Share on other sites More sharing options...
MancheKid86 Posted June 12, 2016 Share Posted June 12, 2016 whats your fuel pressure like? Link to comment Share on other sites More sharing options...
Bogger45 Posted June 13, 2016 Author Share Posted June 13, 2016 Ok now she's running...there's an issue though after replacing the air intake sensor she no longer sputters at 2rpm she drives perfect...however I'm throwing codes: 12,24,21,14,22,and 23. I just replaced the oxygen sensor, map, TPS, and intake air... Ones again she's surviving the check engine light coming on now but throwing those codes( I feel some hesitation) Link to comment Share on other sites More sharing options...
Bogger45 Posted June 13, 2016 Author Share Posted June 13, 2016 Well FML drove good for 30 mons then right back at it. Link to comment Share on other sites More sharing options...
HOrnbrod Posted June 13, 2016 Share Posted June 13, 2016 I have never seen nor heard of any OBD1 4.0L HO engine throwing that many codes and still run. Most every sensor is throwing a code. The only semi-common thing some of these sensors share is the +5VDC reference voltage generated by the ECU. Do you have a volt meter? A convenient place to measure it is at the MAP sensor connector. Disconnect the MAP sensor connector, turn the ignition ON, and measure the voltage at the purple/white wire pin on the connector. It should read very close to 5VDC. Also while you're there, make sure the MAP vacuum supply line is connected and not broken back to the intake manifold. Link to comment Share on other sites More sharing options...
Bogger45 Posted June 13, 2016 Author Share Posted June 13, 2016 Guys appreciate all the input. I decided to take the Comanche to an actual shop and let them run some diagnostics. A lot of things just do not make sense given the fact this is a weather/temperature related issue. I'll keep everyone posted on what they find. Link to comment Share on other sites More sharing options...
Bogger45 Posted June 22, 2016 Author Share Posted June 22, 2016 Problem Fixed: PCM Link to comment Share on other sites More sharing options...
rustybottoms88 Posted June 22, 2016 Share Posted June 22, 2016 Thanks for reporting back. Glad you got it fixxed. Link to comment Share on other sites More sharing options...
HOrnbrod Posted June 22, 2016 Share Posted June 22, 2016 I have never seen nor heard of any OBD1 4.0L HO engine throwing that many codes and still run. Most every sensor is throwing a code. The only semi-common thing some of these sensors share is the +5VDC reference voltage generated by the ECU. Makes sense. Link to comment Share on other sites More sharing options...
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