I Decided to clean out my throttle body the other day since it was black. Now my jeep won't start unless I pump the gas pedal. Once it starts the idle bounces up and down, misfires randomly and sometimes shoots to 2500. until the check engine light comes on. Once it's on, the idle is nice and happy at 800rpm. What in the world did I do? I replaced the tps and iac twice since it happened. I can't figure out what code it's blinking out at me either. It's super unreliable.

If i feather the gas to keep the idle stable in the beginning, it won't throw a code. but it misfires as i drive. letting off the gas will make it stutter and misfire. then it will throw the code, and start working fine.

Vacuum leak?

there is one tiny line thats broken from my intake manifold to somewhere behind the valve cover. i think it connects to something near the wiring harness. ugh

Whats the codes ?

honestly can't even read it. 2...something..2?? 55 55

The smallest things can cause the biggest trouble...Sounds like map sensor line ......

ill take a look

12 and 55 are batt and end of test...http://jeep-xj.info/HowtoECUcodes.htm

trying really hard to read it. 12 seems right. the battery had been disconencted a few days ago. would the map sensor have a code? oh saw the link..

thats exactly what is broken.






...i feel so stupid

Very common ....Might not be whats wrong deff fix then cross fingers ....

might as well keep all these replacement sensors i purchased.

If theres no codes don't replace any sensors ever, computerized systems are there to help in trouble shooting issues.....

hmmm, when my CPS crapped out, it didn't generate/store a code....neither did my NSS....

i just assumed starting my car in neutral was a feature lol