I can run the Disco in the driveway for an hour without stalling. But then if I drive around the neighborhood, after about 15 mins the engine starts missing and then it stalls. What????

 

What maintenance have you done to it? Whats the condition of the engine? Mileage?

 

If that occurred in my Disco II I would KNOW it was the MAF (because the exact thing has happened to me three times in 19 years of ownership). Not sure on a Disco I.

 

Thanks Charlie, when the MAF messed up how long before it would start again? When mine stalled, I can wait a few mins and it will start and run for a few mins. In fact yesterday I was a mile away from home when it stalled after shuttering. I opened the hood (bonnet) to see if the motor was over hot. Not finding anything out of order got back in and started it up and drove back home.

 

A few sensors when old and heated will fail, when they cool all is good. I'd check the Crankshaft Sensor and it's wiring behind the drivers side exhaust, it gets mighty hot right there.... The other culprits would be the Idle Air Solenoid and the Throttle Position Sensor. It's kind of a hunt and peck to find which one..... Rover style. When a MAF fails on a D1 the motor usually runs really bad from start to shutdown and burns a bunch of fuel in doing so.

 

When my MAF is failing (or dirty... there is a debate concerning cleaning them) it runs fine when cool then feels like it is misfiring when it warms up, and gets progressively worse. Mine shows a misfire code, sometimes on one cylinder and sometimes random. A general misfire accompanied by an internal (3,5,4,6) misfire always makes me think MAF. The first time it happened I was in a bucket of woe because I thought I had bad head gaskets (that I had recently replaced), but DiscoMike grumpily told me to get a new MAF. Skeptical, I swapped MAFs with a friend for a few minutes and all troubles disappeared, so I bought a new MAF (and now I keep a spare, for peace of mind).

The element on the MAF gets obscenely hot when the truck is on; hot enough to immediately raise a blister a couple of minutes after the truck is off, if you touch it (I KNOW this). I don't know the temperature, but I am sure the main heat dissipates fairly quickly when the truck is off. I cannot remember how long it took to normalize (it has been a decade or so).

If you are in the "clean it" camp you should let it cool overnight and use MAF cleaner from an auto parts store. I'm not in that camp (though I do have several cans of MAF cleaner), because if there is something wrong with the MAF (other than oil or dirt) cleaning can make your mind wander to head gaskets and cracks. Best bet is to borrow an MAF from a good running Disco or get a new MAF.

ihscouts clearly knows more about D Is than I do. His sounds like very good advice and I defer to his wisdom. I have a 2000 D II and new D Is were still on the lot, but I had to have the new one... I've always wanted a D I and passed on the opportunity to have a Mercedes diesel powered one, to my eternal regret.

 

Will be doing some hunting and pecking this weekend. Sounds like some good suggestions. Will also check the fuel pressure to see if fuel pump is keeping up.

 

I have found that 95 Disco does not have a Crankshaft Sensor. Am thinking it may be the distributor. How can I test the Distributor?

 

Traditional first place to look is the fuel filter. Back in the days..fuel would flow till the offending particles clog up and will then clear after sitting..
Just a thought.

 

check the air duct for leaks.