Stalling under load

[sprater92]

jeep is stalling under a load, only going in forward gears, i can drive in reverse no problems

things ive done and replaced
battery and all connections
coil
alternator
crank sensor
cam sensor
tps sensor
iac module
map sensor
checked timing
fuel pressure stays around 45psi

jacked the jeep up and can run through all gears no problems at all, set it back down falls on its face pcm?