Bucking/kicking/weird idle/stalling

My 98 xj has been having some issues. It will feel like it's not getting enough power and I will hear a knocking/kicking sound near the driver's side. If I mash the pedal sometimes it will get power, but it will start to buck if I don't keep her at 3000+ rpms. It will also buck and idle high or idle too low when stopped. Along with sometimes stalling at a stop. The problem gets worse the hotter it gets. I thought it may of been the TPS based on research, but I replaced it with a Mopar TPS and it's still having these issues. The only other thing I can think of is CPS, which I will try to test today. But I'm unsure of that because normally the CPS will just fail outright and not work. The only codes I get are p0700 and p0751, which has to do with solenoid a. I already ordered a master solenoid replacement kit and plan on doing it over the weekend. I could really use your guys help in troubleshooting my problems!

You the second one with the 'bucking' complaint.............O2.


NTK only.

I would also like to add that I got seafoam for the throttle body and that helped stop the symptoms when cold but it starts doing it all again when hot.

Bucking, stalling, and backfiring is almost always an O2 sensor issue. Test the O2 sensors. Inspect the O2 sensor fuses, inspect and test the O2 sensor wires for damage and short circuits, inspect the O2 sensor plug for corrosion and pushed back wire plug pins. Only buy NTK brand O2 sensors.

If everything check out OK with the O2's, test the Coolant Temperature Sensor and wire plug/wire harness.

Tim_MN said:

Bucking, stalling, and backfiring is almost always an O2 sensor issue. Test the O2 sensors. Inspect the O2 sensor fuses, inspect and test the O2 sensor wires for damage and short circuits, inspect the O2 sensor plug for corrosion and pushed back wire plug pins. Only buy NTK brand O2 sensors.

If everything check out OK with the O2's, test the Coolant Temperature Sensor and wire plug/wire harness.

Click to expand...

Ok. I did a reset and now I'm getting po137 and p0132 which is o2. I am going to inspect them. Why ntk specifically? I know bosch is bad for Jeep's.

Here is a video of the kicking, starts at about 14 seconds and only goes on for about 3 seconds. You can see I'm pressing the gas but it won't rev. Sorry for the angle and quality >.>. I can try to take a better video if needed. Before this I had to rev it hard in park because it would die immediately if I didn't.

Or a vacuum line leak from the throttle body to the MAP sensor. 2 weeks ago I discovered a dying sheer pin on the distributor helical gear that holds it in place on the shaft can do this. First clue was too much rotational play on the rotor.

OP: Disconnect the O2 sensor and see if the problem stops, and also check for melted damaged wiring on the O2 harnesses!!!

Tim_MN said:

Bucking, stalling, and backfiring is almost always an O2 sensor issue. Test the O2 sensors. Inspect the O2 sensor fuses, inspect and test the O2 sensor wires for damage and short circuits, inspect the O2 sensor plug for corrosion and pushed back wire plug pins. Only buy NTK brand O2 sensors.

If everything check out OK with the O2's, test the Coolant Temperature Sensor and wire plug/wire harness.

Click to expand...

Ecomike said:

Or a vacuum line leak from the throttle body to the MAP sensor. 2 weeks ago I discovered a dying sheer pin on the distributor helical gear that holds it in place on the shaft can do this. First clue was too much rotational play on the rotor.

OP: Disconnect the O2 sensor and see if the problem stops, and also check for melted damaged wiring on the O2 harnesses!!!

Click to expand...

My harness is pretty shitty and the pigtails are super worn, but I didn't see any real damage...just some lazyness from the last owner. I disconnected both sensors, one of them was hardwired...Still the same issue except now I sound like a ricer. I also found some coolant near my o2 sensor(didn't seem like the sensor got wet) on the exhaust. Could it be a intake gasket? I ordered a live obd2 scanner and it should be here within 2 days so I can run some diagnostics. I will try and upload some pics later

edit: couldnt embed pics so here is a link to the gallery, red circle is coolant.

Run a vacuum gauge series of tests, and pull the spark plugs, lets see what they look like?

Check the distributor to see if the basic mechanical timing is off.

Is the transmission slipping????