I have a late-model D1 with v8 and ZF auto. I'm wondering if there's a way to keep it from stalling in offroad driving after the tires start spinning and then I stop. Like yesterday I was busting snow and ice with the diffs. I was locked in low-range and every so often I would get high-centered on the ice between the wheel ruts. The tires would spin and I'd stop to back up while I still could. Sometimes it would stall. Other times I was high enough I couldn't back up and I'd spin in reverse, let off and it would stall. I'd have get out and clear the snow and ice around the axles with a shovel so I could reverse and get another run at it. I think my transmission is working ok. It will stall on a steep hill in hi for sure, but it usually does fine in lo. Now I'm not that experienced of a driver so I don't know if there's a way to keep it from stalling, but I know that some momentum helps to get through a dodgy patch, so I put the hammer down to bust through. I get so far and then once I'm not getting any farther, I let off and it stalls. Once I'm stuck I'm not using too much throttle to try to get unstuck, just trying to back up gently if I can. I did make it through a few deeper drifts and to the top of the hill (the upper part had less snow since it had melted), but I was embarrassed by all the stalling.

 

c'mon, am I the only amateur here?

 

So have you changed fuel filter (ever) and do you have 32-34 PSI at the fuel rail when running?

 

When coming down from high rev's it is not uncommon for this engine to stall, its not tuned for high revs.
It has happened to me before.
But has not happened in a very ling time.
Start with the basics, clean the throttle body and idle air control valve.
Also make sure all of your PCV lines and oil seperator are clear.

 

Ok, the fuel pressure at the rail at normal idle speed (600-700 rpm) is 30 psi exactly.

Both the vent hoses on the valve covers are new. I have cleaned the MAF and IACV recently (for other reasons, and that did not affect this either way).

On the passenger side PCV, the hose is new and the nipple on the plenum is clear. The nipple on the valve cover is funky. It looks like it has some plastic in it. I'm not sure what it's supposed to look like.

I had stalling in the axle-deep snow again today. I can accept this may be just the way the torque-converter and this engine work, but I want to make sure I'm not missing something.

 

ok, I searched and found out about the oil separator, so I'll pull it and check the status/clean.

 

I cleaned the oil separator and inside the pocket of the valve cover. It was a little crusty but not enough to stop up the flow. It will certainly flow better now.

I think the problem with stalling is just the result of going from high rpm to a dead stop of the output side of the torque converter, which drags the motor down to a stop. I wonder if I can avoid it by shifting into neutral. It might work but might also not be possible in the circumstances.

I heard that newer Defenders have a stall prevention program in the engine management that automatically keeps this from happening, but that people have complained about an undesirable effect where it can begin to accelerate the motor on steep descents.

 

The stall prevention on the new Defender is not anything like you are thinking.
It is for manual transmissions.