ajess

hi guys,
I have a 2000 cherokee 2wd inline six with fuel inject. A few nights ago headed to work it started to surge and jerk and the engine light came on. after work the light was off but still periodically jerking and lunging and at stop lights it would idle down to like 200 rpm, barely running. and would shift kinda weird. then at home i shut it off and tried to restart it, pops and sputters.
Since then i have cleaned the throttle body, changed the TPS, scrubbed the IAC, filled the gas tank full. after changing the TPS it runs really good and shifts normally again. but if i turn it off after its warmed up and try to restart it, it still pops and sputters and doesnt want to start. just changed the plugs, still doing it. when its cold it starts fine.

any help would be a blessing, thanks
andy

Radi

Does it start normally when the engine is cold?

ajess

not perfect but yes cold start is much much easier/better than after its warm. vaccum leak maybe?

cruiser54

Your Jeep is trying to tell you something with the codes. What are they?

ajess

the guy at autozone said they cant pull codes since the engine light is not on. is that not true? ill take it to a different one and see if they can try anyway just in case

ajess

had them run the code check and it said NO codes. iam stumped

Turbo X_J

If the CEL actually illuminated, there is a code. Go find it & report back grasshopper.

ajess

the CEL only came on for a few mins when this all first started. when they hooked up the machine, it read "no codes."

Red Limited

Check for a intake leak, check your intake manifold bolts to make sure they are tight. You might want to test the EGR valve for correct operation. Good luck.

cruiser54

No EGR after 1990. OP has a 2000.

ajess

okay so heres a new wrinkle. i got a DMV renewal notice in the mail a few weeks ago. figured since it starts, and autozone says theres no codes right now ill go have it smog checked so i can at least have current plates while i try to figure out what exactly is wrong with the jeep. the smog guy said the OBD monitors are ''not complete'' and the jeep needs to go through a "drive cycle" to make them ready to test. does anyone know how long or far a drive cycle is?

ckysodkorn_xj

50 miles.

ajess

some guy told me 500. i like 50 better haha. thanks.

rrich

50 to 100 miles - depends on which portal hasn't reset.

Sounds to me like the coil is going south. They often short internally hot, but work cold.

Try this - get it hot so it acts up - pull a plug wire at the plug and hold it above ground to see the spark while running (insulated pliers.)

The spark should be a thin crisp snappy blue spark if it's good.
Anything else is bad - yellow, red, thick, wide etc. is not.

Aftermarket coils from China (Autochina,O'Rieley's etc)are only good for a few months. Dealer or Napa! If NAPA, ask for the good ones - they sell both.

If it's the coil rail type - hot, then listen close to the rail, you often can hear it shorting inside "snap snap."

Red Limited

Oops! My bad. Forgot, no EGR in the 2000's.