Hi All,
I have a 2000 sport AT 4.0 4WD w/ 234K miles. Got it a few years back and has been a problem since day one. Lately it's been a bit hard to start sometimes and more recently it's randomly shutting off. I've been having to use the gas pedal a bit when starting. Most times it fires and runs, but other times it dies immediately and so I turn the key off, wait, back on wait, then crank to fire and it runs.

Now, driving down the road and the engine stops running. This is happening nearly every time we drive it. So a few times per day it's shutting off while driving. Until last night, I could pull over, turn the key off a sec and fire it right back up. Last night I was 20 minutes trying to get it running again.

When it dies on the road, I barely notice that it died. There's no bucking or chuffing, nothing weird or strange, just suddenly the engine isn't running and RPM's drop to 0. Last night I kept it coasting in drive and kept taping the gas pedal... Call me CRAZY but the dang thing started back up, in drive, not turning the key... it just came back to life. I didn't even know an AT could do that. lol.... Went from zero RPM coasting down the road to running at full tilt without turning the key.

It didn't throw any codes last night, but before that I had cleared a bunch that were stored. All of the EVAP codes (very small leak, small leak and gross leak). I have checked over all vacuum lines and all good. One on the charcoal canister was a bit crusty so I replaced it, but no change in anything really. Other codes cleared were P0300, P0301, 03, 04, 05, 06... all misfires. A single trans code - P0705.

The shifter... In all positions the transmission function matches.. in R I go backwards, in D I go forward etc... I can start in park and neutral. In reverse the reverse lights don't come on. I kinda have to hold the shifter on the balance between R and N to get the lights to turn on. When parking I shift into park but can't turn the key off until I push the shifter forward again. Like it has too much tension on it....

This is my 4th jeep because I love them... I hate this one, but we desperately need it running reliably again.

Thank you,
John

 

Check your crankshaft position sensor. When they fail, they cause the exact symptoms you're describing: random stalling, hard starting, and no codes. It's a very common issue on the 4.0L.

Your shifter problems are a separate issue. The part that tells the transmission and computer what gear you're in is called the neutral safety switch. It's on the side of the transmission. Yours is likely faulty or needs adjustment, which is causing the reverse light and starting issues.

 

Hey Roberto. Thanks for the tip. I'll get to dealing with the crank sensor today. I did swap the NSS from my 98' a couple years back thinking that was the problem with the reverse lights. Didn't change anything. Seems there's too much tension on the cable from shifter to trans.

Thanks again,
John

 

Ok. That seems to have done it. Dang thing fired up lickety split! I guess looking back.. without the codes and everything else I would describe the symptoms as; a while back i started having trouble starting once in a while, then it became more often so much so that I just would expect it to not start and stay running on the first try. Then it began stalling out while driving on occasion to where now it would barely make it a mile before shutting off, but would still fire right back up. This last time it was 20 minutes or so before it fired up. It just started and ran like it hasn't in quite some time. Thanks again!!