Hi. I have a 1995 3.9 V8 Disco which is used mostly off road. The problem is that sudden stops and stopping when going down steep inclines while in low (also while in high sometimes) causes the vehicle to stall. It starts up right away without any problem. When in drive, there is a bit of erratic idling here and there, mostly having the revs drop a bit and then pick up to normal.
I have changed the mass air sensor, put in new lambda sensors, checked the sensor motor and have had a full 200k maintenance. While hooking up to the computer, I get a reading that the left bank of injectors are not on par so I am waiting to receive 8 new ones and swap them in for the old ones.
After searching the forums for a similar problem, I have come across a few more ideas such as a faulty camshaft or crankshaft position sensor as well as checking the fuel pump pressure (though I have a feeling it's not the fuel pump). If anyone has any ideas on this subject I would greatly appreciate it!
1995 Disco V8 3.9, tires 245 75 16 mudders, Warn 9000 lb. winch, Arb front and back diff locks, Rhino Guard roof rack, 25 liter water container on roof, Waeco fridge

 

So when you come to a stop the engine stalls?
When it idles low if you give it gas does it stumble and then take off?

 

What are the exact fault code numbers you are getting? Have you replaced your fuel filter? nI don't think injectors will fix this problem cause they don't all fail on bank at a time.

 

Thank you Spike and Mike. When I come to a stop especially in Low the revs plummet, if I catch them on time and give a bit of gas they go back up to normal. I get a not on par reading from the injectors on side B, all other readings are now ok as I have changed the mass air flow sensor which was faulty as well as putting in new lambda sensors. I have taken out the stepper motor and cleaned it, I will be replacing it today anyway and putting the idle revs up a bit as I am going down for 3 days to the desert to do some wheeling. If you guys have any more suggestion I will be happy to hear them. Thanks!

 

This sounds like a bad TPS issue to me.
Mine did a similar thing, coming off the expressway and stopping at the end of the exit ramp the engine would all but stall.
RPM's would drop, engine would stumble, then come back on its own.
If I gave it gas it would come back.
As it got worse it would also happen at low speeds, like while parking.
Replaced the TPS and all is well once again.

 

what's a TPS?

 

Throttle position sensor.
It is what tells the cars computer what position the throttle is in.

 

Stepper motor

 

The stepper motor is a different thing, that is the idle air control valve, it is a electric motor with a plunger on it that controls how much air the engine gets while at idle because at idle the throttle plate is completely closed and the engine would not get enough air to run otherwise.
This is the same reason that if your truck will not idle on its own that the stepper motor (IACV) is the #1 suspect.

 

Intermittent low fuel pressure, carboned up idle circuit, worn throttle plate shaft causing tps to fluctuate, fuel rail corroding on the inside etc, etc...