This sounds like the same problem I have been having and just posted under the Stranded Disco title. Only mine is a 2000 DII.

 

Make sure to inspect the harness wire itself when replacing the Crank position sensor. Often the sensor will function just fine and it's simply a matter of one of the prongs of the harness having come loose. You'll tear your hair out after replacing the sensor, yet still having the stalling when warm problem. Pull on each individual wire in the sensor harness to see if any of them are loose.

 

When you find out what the problem is PLEASE let me know! You have described how mine runs to the "T". I only have trouble starting it after multiple short trips around town (after the engine warms up). It idles really poor with stalling and backfiring if you try to accelerate. I have a check engine 1107 code which I think indicates the long term fuel trim is too low (reads around -23). The short term fuel trim appears in the "normal" range. I have been pulling my hair out for a while now. PLEASE HELP ME!!!

 

I just got back from my INDY and this is what happened....

Drove 45 minutes to get there in traffic so the truck was really warmed up. He then tested the fuel pressure at the rail with a Snap-on fuel pressure tester. Pressure was between 35 & 40 so we thought we were good. Turned the truck off to make sure the pressure stayed in the system with the gauge connected. While that was testing we replaced the fuel temp sensor. 5 minutes later we checked the gauge and the pressure was creeping down with the truck turned off. In about 5 minutes time the pressure was at 10. Dropped 30psi in 5 minutes!

We then tested for a few more times. Turns out the pump was letting fuel and pressure creep bank into the tank. So we replaced the fuel pump and it now only cranks like twice when it is really warmed up compared to 5-8 times. I hope this is the fix....

Let me kknow if this helped you guys at all....