Motor sputters & dies with offroad inclines

sierradmax

TJ Addict
Supporting Member
Joined
Jan 1, 2020
Messages
1,044
Location
RI
A friend of mine has been trying to wheel with us and has been plagued by a gremlin. His 06 4.0L TJR automatic does not like to climb obstacles while on a trail. It will sputter and/or die, resulting in a no-start or long crank and often setting a CEL. Codes that come up are for the MAP sensor, Camshaft sensor and one of the O2's. On the road, flat trails, or declines, it works absolutely fine. Since the onset of the battle, he's replaced the fuel pump, OPDA with Mopar & aftermarke CPS's and it continues to do the same. The only time he can get it to repeat is while on the trail.

I looked at the wiring schematic and all 3 sensors have a different signal wire but share the same ground. I plan on testing the ground but has anyone stumbled across a similar issue and resolved it to something different?
 
So for sure, the engine actually dies? And it only dies on inclines? I can understand the transmission stalling and acting like it's in neutral when on climbs but not the engine.
 
Yes, engine. Usually on first incline, it sputters then dies. Hard start and 2nd attempt, it dies.
 
This may not be relevant but I had a vehicle do that one time and it was a deteriorated if you’ll pick up in the tank...I realize the design of the fuel pump may not allow that to happen in a TJ but I’m just throwing out an experience I had.