Discovery 2 Cutting Out

Hi everyone. I need a fresh set of eyes on this problem as it has me stumped. I have a Discovery 2 ES 4.0 V8, dual fuel with lpg. Its a 1999 model, currently showing 96,000 miles.
She's been laid up for 2 years in my garage, purely stored not for any faults but has just been put back on the road and for the past month has performed faultlessly. However, last night after we ran out of lpg and refilled it, it has taken to cutting out when it gets to operating temperature. Just prior to this, it idled a little lumpily. I have checked the plugs and leads today and they are all ok, and checking back, they have only done 8000 miles.
The lpg system is a Prinz system and was fitted professionally 3 1/2 years ago. Initially I thought it may be that playing up, but I have run her on just un-leaded and get the same effect. She starts and runs ok but after about 8 miles, she just cuts out with no warning. Its happened at a junction on idle and at around 50mph. She'll turn over fine after but won't start. If it's left for around half an hour or so to cool, she'll fire up perfectly and then carry on until the needle is in the middle of the temperature gauge and then just cut out again.
It really has me bewildered. I have checked all the levels and they are all fine. I don't see there being any link between it reaching normal temperature and it shutting all the fuel off, which appears to be whats happening.
I would appreciate any suggestions before handing it over to the local lpg fitter as bills from him tend to be high 3 figure numbers for quite small jobs and i'm sure it is something really simple I have overlooked.
While I remember but I don't know if this has any bearing on the problem, the hand brake red warning light has started to come on. I put this down to just a loose connection, but is it an indication of a limp home facilty that Range Rovers have?
Thanks very much in advance.

The warning lamp is not related,have you tried checking for a spark at any of the plug leads when it conks out.

Sadly everytime its done it, not had any tools to hand. Happened to the wife twice last night, by the time the AA arrived, it had cooled sufficiently to start, so made her look good to the patrolman.
I've tried to get it to do it when its on the drive but it only seems to happen when its on load, thats to say, it left me stranded twice today.
I'm going to recheck all the lpg connections tomorrow, just in case. Could the Lamda sensors cause this as they have played up before? There are so many sensors supplying the ECU on this, I can't think where to start.
A friend has suggested re-setting the ECU by disconnecting the battery for half an hour. I didn't think this worked, or rather it didn't when the 3 Amigoes visited the dash.

eightinavee said:

The warning lamp is not related,have you tried checking for a spark at any of the plug leads when it conks out.

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You don't need any tools to check for a spark.

2 yrs ago had a simular fault ,it turned out to be the Crank shaft position sensor ,not to difficult to change .A strange but true coincidence a mates one packed up a week after mine !

Paul Whipps said:

2 yrs ago had a simular fault ,it turned out to be the Crank shaft position sensor ,not to difficult to change .A strange but true coincidence a mates one packed up a week after mine !

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Thats exactly what I was heading towards,but I didnt want to suggest it before we had news of a no - spark situation.

Hi, got recalled to work before I could check anything out. Just got it to cut out on the drive and when it dies, there is no spark to the plugs until it cools down again. I'm getting afriend to lend me his code reader, so hopefully, it being a 1999 model, it will tell me the code for the fault. Has anyone any ideas what the Crank Shaft Postion sensor fault code is?
As an aside, how do you check to see if you have a spark if you have no tools? Its a new trick that I've not heard of being able to do.

Just pull off a plug lead,plug a spare plug into it and get a handy assistant to crank it while you watch.Have to say it sounds very much like a crank sensor failing when it gets hot.There may not be a logged code as there is no back up for the crank sensor and the engine ecu will just think it has stalled.

eightinavee said:

Just pull off a plug lead,plug a spare plug into it and get a handy assistant to crank it while you watch..

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Or just hold the end of the lead against the engine block (not quite touching). Won't tell you how good the spark is, but you should see a spark!

thanks guys for the reply. Bit squirmish with elec-trickery. Got zapped too many times owning 101's to try that without a set of insulated pliers.
From how you describe the fault with crank sensor, it does feel a bit like stalling. I've looked up the prices and its one of the cheaper sensors thankfully. I shall get it changes and let you know how it goes.
Many thanks for all the advice.

Hello again. I'm still waiting on a sensor from Yeovil L/R, been on demand for a couple of weeks now, apparently the computer says no. Solihull don't have one according to them.
I've just tried to fit a second hand one from a Range Rover to confirm its the crank sensor thats at fault, couldn't get the plug to fit as they don't seem to have given much slack in the vehicle loom.
I've put the original back on and now it runs ok, but has an occasional hic-cup when warming up and then cuts out as it used too. And being Christmas, the dash has gone all festive and I now have flashing green M and S cog symbols which relate to the auto box.
Anybody got any ideas or know of a trustworthy garage in Yeovil area that can look at it for me?
Many thanks.

don't blame you on the spark plug bit mate 30,000v is not nice!

Give Richard a call; West Somerset Land Rovers Decent bloke,should be able to help you.