Oh boy, here we go. So I have a 98 4.0 4x4 and I'm having some interesting issues that have started recently. So when's it's cold out the Jeep will have a stumbling problem intermittently while driving. The engine will stumble and save its self and act like it never happened. I've noticed when this stumbling happens the temp gauge will fall all the way to 0, stay there till it saves itself and then go back to the correct temp. The plugs, wires, front O2 sensor, cap and rotor, CPS and battery have all been replaced in the last year and a half. This is my DD and I need it fixed quickly and I don't like the idea of it stalling and me getting stranded. Anyone got any ideas?

 

Does this happen when your Jeep is still warming up or at operating temp? Also, take a look at your engine grounds and clean em.

 

Ever cleaned the throttle body and IAC?

http://cruiser54.com/?p=60

 

It only happens when it's warming up.

Yup, I have.

 

This sounds dumb and I might be way off here but I've heard the coolant temp sensor does send information to the ECM in regards to fuel and air delivery based on the engine's temperature. You mentioned the temp gauge drops whenever this happens, could be related?