Alright well my Jeep, 99 cherokee 4.0 auto, has a usual sputtering problem right when I start it up does it in idle, go down the road and mash it, it spits and sputters then goes away.

It has brand new crank sensor, brand new cap, rotor, plugs, 8mm wires, coil, the cable for the Trans cable has been adjusted, has a new throttle position sensor. Now the throttle position sensor I have replaced so many time I think I have 6 here At my house they all push out at idle 1.2-1.8 volts.

Heres the kicker, I cleared the codes in the pcm with my code reader, then the light popped back on that same day later. Went to check the codes and won't let me read it. So went to my wifes car to check my reader to make sure it was fine it keeps saying error. Went to auto zone(I know them all there so walked in a grabbed the code reader) read another guys codes then went to mine, came up the same as mine, error. Now it won't read codes. So really confused.

I was told that the Jeep has a larger throttle body then normal can that make a difference, there's no vacuum leaks, no problem with the fuel pump, injectors all spray right, spark plugs all spark properly. Idk any more.

 

Can anybody help?

 

Have you checked your compression? Even a 10% difference can affect it that way..

 

Check the wiring harness right above the valve cover. Dollars to donuts theres probably a melted wire up there.

TPS is the usual culprit but if you've done all this I'd say probably wiring.