Idle Issues-intermittently

[dtsn280z]

I have an '01 Limited 4 door with the 4.0L, 2 wheel drive with 106K on it. I do alot of stop and go. Sometimes when I get back in and crank it, it idles really rough. I give it some gas and it will rev and back fire a few times. Within a few seconds it's back to normal and runs fine. I've tried all grades of fuel to see if thats the issue. It has the distributorless ignition system as well. I've noticed that when it's cold outside it doesnt do it. (By cold I mean 30's to 40's, and that is cold in Florida). Now that it's back in the 70's it's doing it more. I average around 16 mpg which seems in line with my previous '95. It was doing the same thing when I sold it and it had 135K on it.

Any ieas? Any advice will help.

Thanks!

[fredjacksonsan]

Hmmm...could be a number of things. First thing I would ask is how long it's been since the spark plugs were changed. If those are new or changed the last 15K, then I'd think it might be the Crankshaft Position Sensor.

[2000izusu]

i believe oo-01 had a tsb to address this issue, and it involved a heat shield for one or two injectors. forget which ones?

[dtsn280z]

Thanks for the help. I just bought this one and I have no idea when the plugs were changed. I runs great otherwise. When I crank it in the morning or after sitting a while its fine. Only runs rough when cranked after sitting five or so minutes and when the air temp is 70+ degrees. Otherwise if it sits for 30 mins. to an hour its fine.

Thanks again.