Stalling after engine braking

[GudaXJ]

I noticed my 98xj doing this last wheeling trip. Basically going down hills on trail rides i would be in 4lo in 1st gear and just ride it down instead of riding my brakes. When i would come to a stop i would engage the clutch and shift out of gear. I started noticing when i would engage the clutch the engine would die. I would start up again and continue riding down the trail and when i would engauge the clutch to pull it out of gear it would either sputter to 500rpm then die or just quickly shut off. I also noticed later on the trip i stalled it on a steep hill and tried to start and it wouldnt. Seemed like it wasn't getting any fuel. I don't think it's my fuel pump cause its less than a year old and its oe. I had a little less than half tank so i ignored it. When i got home i filled up and tested this on my driveway. I'll be in 2wd and ride 1st gear down my driveway(which is sorta steep) and when i engage the clutch to pull it out of gear it will either drop to 500rpm and then recovers or just dies. Its not as consistent but it does it. What i remember what used to happen was when i would engage the clutch the rpms would rise a little and then back to idle, not drop. Any input is appreciated. Thanks!

 

[langer1]

Engine model? I would start with the IAC on a 4.0.

 

[GudaXJ]

Its a 4.0. Whats the IAC? Thanks again

 

[GudaXJ]

No one else has any input?

 

[K2fender]

Idle air control...have someone run a diagnostic on the obd codes and see if it comes up...

 

[GudaXJ]

Okay so i finally got around to messing around with the problem. I replaced the idle air control and it still stalls or comes close to after riding the engine down steep hills. Since then i've got a new exhaust so it has new o2 sensors. Possibly cps? None of my friends can figure it out so please help!

 

[langer1]

After steep down hill could be a fuel pickup problem.
Also there is a check valve in the tank vent system to prevent liquid fuel from getting drawn into the evap canister.
If that valve is not working it could cause a ritch condition after a steep down hill run.

 

[langer1]

 

[GreenbeltXJ]

fouling the plugs?

 

[GudaXJ]

I'll def. look into that. I dont think its a fuel pickup problem cause it idles fine on steep inclines, the problem only occurs after engine braking. Btw where is that check valve located on my 98xj? I don't think i have a charcoal canister. Thanks again for your help!

 

[smccollamjr]

My '96 does the same thing. I always thought it was because the RPMs were too low when I depressed the clutch. My solution: when I get to the bottom of the hill I accelerate a little before I shift. I'd like to know what the real solution is though.

Mine is also hard to restart if I stall it going up hill (from a stop). If I hold the accelerator to the floor (like you do when it's flooded) it always restarts. And by the looks of my exhaust tip I am running a little rich.

I think our XJs are related.

 

[GudaXJ]

Does anyone else know what it could be cause its reallllly annoying!!!!