Hi - thanks in advance for help. Been having this issue for a while, but it's upped it's game to stalling on the highway, so I need to get this sorted.
Jeep - 2006 4.0L Sport 2 Door Manual, 98000 miles.
Issues & Situations:
Idle - The standing idle is ~700. It's a smooth idle before any driving cold and can be that way for a while. While in a "clean" idle - the needle is steady and doesn't move around. Once I take her out and drive around, the engine will rev at stoplights intermittently. The RPMs fall first, down to ~200, and then she punches back up to 1200 before resettling around 700. Depending on how bad, the check engine light may flash on - but no codes are being stored. Anecdotally, it seems to happen more after faster driving/coming off the highway.
Stalling - Primarily/started happening when leaving the stoplight. As I pull out the clutch, the engine light comes on, the RPMs fall and she either dies, or I save her on a dance of clutch and gas. I know it's terrible, but it doesn't happen when I keep the engine engaged with a gas/clutch mix at a long light. It seems to be the idling and then transitioning out of the idle. It first started when coming off the highway only, but now has graduated to all types of stoplights.
Highway - It's recently died twice on the highway. There is no rhyme or reason, no bumps. Just regular highway. I lose all power steering, but lights are still on.
It generally turns back on right away, but every once in a while I'll have to give her a few minutes. I've never gotten a code even though the light flashes on.
Investigations so far:
-IAC and throttle body are clean (thanks forum)
-New O2 sensors as it was time (NTK - thanks forum)
-New fuel pump as I needed one (Mopar) - so don't think it's fuel pressure
-Cleaned the contacts on the IAC, MAP and TPS electrical houses
-Followed pretty much everything on the ZJ Dirty 12 write-up on the Jeepforum - aka cleaned grounds, did battery tests, tested relay box (switched 'em around), did sensor wiggling (carefully) - nothing really seemed to change the idle problem.
I've taken it into 3 different mechanics now and she won't act up when with them. They just say the Jeep looks good and aren't sure. The rough idling is generally consistent, but the stalling will be bad in a series, but then settle down and not rear it's head for weeks.
Any thoughts? Read a lot of similar threads, but I wanted to get my specifics to see if any sticking point of mine would 'Aha' for you experts.
Jeep - 2006 4.0L Sport 2 Door Manual, 98000 miles.
Issues & Situations:
Idle - The standing idle is ~700. It's a smooth idle before any driving cold and can be that way for a while. While in a "clean" idle - the needle is steady and doesn't move around. Once I take her out and drive around, the engine will rev at stoplights intermittently. The RPMs fall first, down to ~200, and then she punches back up to 1200 before resettling around 700. Depending on how bad, the check engine light may flash on - but no codes are being stored. Anecdotally, it seems to happen more after faster driving/coming off the highway.
Stalling - Primarily/started happening when leaving the stoplight. As I pull out the clutch, the engine light comes on, the RPMs fall and she either dies, or I save her on a dance of clutch and gas. I know it's terrible, but it doesn't happen when I keep the engine engaged with a gas/clutch mix at a long light. It seems to be the idling and then transitioning out of the idle. It first started when coming off the highway only, but now has graduated to all types of stoplights.
Highway - It's recently died twice on the highway. There is no rhyme or reason, no bumps. Just regular highway. I lose all power steering, but lights are still on.
It generally turns back on right away, but every once in a while I'll have to give her a few minutes. I've never gotten a code even though the light flashes on.
Investigations so far:
-IAC and throttle body are clean (thanks forum)
-New O2 sensors as it was time (NTK - thanks forum)
-New fuel pump as I needed one (Mopar) - so don't think it's fuel pressure
-Cleaned the contacts on the IAC, MAP and TPS electrical houses
-Followed pretty much everything on the ZJ Dirty 12 write-up on the Jeepforum - aka cleaned grounds, did battery tests, tested relay box (switched 'em around), did sensor wiggling (carefully) - nothing really seemed to change the idle problem.
I've taken it into 3 different mechanics now and she won't act up when with them. They just say the Jeep looks good and aren't sure. The rough idling is generally consistent, but the stalling will be bad in a series, but then settle down and not rear it's head for weeks.
Any thoughts? Read a lot of similar threads, but I wanted to get my specifics to see if any sticking point of mine would 'Aha' for you experts.
