running problems stalls going forwards, runs fine in reverse

[OSHAGNASTY]

i have a 1988 jeep comanche 4.0 I6 Automatic,

it will crank up fine, it will idle fine and if you put it in drive it will stall out, but it will run fine in reverse. any forward positions, it will stall out if u give it gas.

any tips?

[JeffK]

That's tough without seeing it. I would follow the diagnostic rules I used during my dealership days: 1) recheck any recent work, 2) check for the obvious (in your case, vacuum/wires/plugs/coil) and 3) dig deeper if needed. Usually the first 2 worked for me.

[OSHAGNASTY]

That's tough without seeing it. I would follow the diagnostic rules I used during my dealership days: 1) recheck any recent work, 2) check for the obvious (in your case, vacuum/wires/plugs/coil) and 3) dig deeper if needed. Usually the first 2 worked for me.

 

yea i don't think it would be anything like that

i did just put a rear main seal in but i don't think that would do it

[Pete M]

Not sure if this helps at all, but I just found a post on another forum where the guy had the opposite issue (ran fine in drive, stalled in reverse) and it turned out to be loose bolts between the trans and engine that allowed the trans to move and it was apparently binding up the torque converter when in reverse.

[Pete M]

I also found this on one of those random "answers" websites.

 

 

it's got to be in the transmission. it sounds like the lock-up torque converter may be staying engaged, thereby loading down the motor and it stalls.

does this happen all the time, or after you've driven awhile and slow down to stop?

above 40 - 45mph the lock-up torque converter engages, acting like a 4th gear. take it out of overdrive and use 3rd gear in town. a transmission service wouldn't hurt, but check your owners manual for service interval and fluid type. when the transmission is in reverse it over-rides the lock-up. the lock-up of the torque converter is controlled by a solenoid, in most cases the dirty fluid can cause the solenoid to stick occasionally keeping the TC engaged. hope this helps, remember 3rd gear in town. good luck.

[Eagle]

i did just put a rear main seal in but i don't think that would do it

There's your answer.

 

You didn't replace the forward main seal.

 

 

 

 

 

 

 

 

 

 

 

 

 

[Exit ... stage left]

[Akula69]

i did just put a rear main seal in but i don't think that would do it

There's your answer.

 

You didn't replace the forward main seal.

 

 

 

 

 

 

 

 

 

 

 

 

 

[Exit ... stage left]

 

LOL

 

 

anyway - could it have something to do with the NSS?

[aemsee]

Naw, NSS would keep it from cranking. not kill it. Sounds like there is a bad connector or wire shorting out when the engine torques in drive, but not in reverse. Does it crap out as soon as you engage drive, or after you start to move?

[OSHAGNASTY]

Naw, NSS would keep it from cranking. not kill it. Sounds like there is a bad connector or wire shorting out when the engine torques in drive, but not in reverse. Does it crap out as soon as you engage drive, or after you start to move?

 

 

it craps out once u give it gas.

[Pete M]

Double check that your CPS wires aren't touching anything (especially the exhaust)

[xflowdaboi352]

Ok we found out today it only does it after it gets hot.

[xflowdaboi352]

I'm updating this for my bro we got the truck running agin and there no stall we did diconnect the battery idk if that did it but it running like a champ! :cheers: