TD5 Misfiring, sluggish or cutting out in heavy rain

Can anyone offer any help / advice for a problem I've just encountered wth my 90 TD5 in heavy rain. Twice now it's showed symptoms of misfiring or cutting out or loss of power when at motorway speeds (65mph) in heavy rain. It hasnt completely died on me yet and the problem dissapears when either slowing down (coming off of the motorway) or the heavy rain subsides. Any ideas!

I think it will be that water has got into the fly by wire signal from the accelerator, I have heard of this and the curel; its along the lines of water getting into a loom and then into the control box... and electricity and water are apparently not friends... so dry out the wet loom, and seal the ends up with silicone so water cannot find a path into the electrics anymore.

Many thanks! I will give it a go and see how I get on. The Land Rover main dealer came up with nothing, as expected, saying they had plugged it into their diagmostics system and no faults found. Alarming really when I made it clear that the symtonms only appear in heavy rain. One day they might actually lift the bonnet open!

There should be driver demand faults logged if water gets into the loom near the throttle pedal,stuff like signals implausible etc.If the 5v supply to the pedal is dragged down the engine will go back to idle and not rev up till you key off and try again - as long as the supply is restored.
It is more likely to be the crank sensor signal signal being corrrupted,this is about the only sensor on the engine that will stop the engine if the signal fails.If the signal is killed cleanly enough,it also wont log a fault - the engine ecu will just assume you have stalled it.This may explain the "no faults logged" issue.

The crank sensor: is it related to if the engine RPM gets to low on a TD5 it just switches off, and I don't mean stalled... with the others, they will keep going to the point that they physicaly stop through lack of speed... but the TD5 seems to shutdown...

discomania said:

The crank sensor: is it related to if the engine RPM gets to low on a TD5 it just switches off, and I don't mean stalled... with the others, they will keep going to the point that they physicaly stop through lack of speed... but the TD5 seems to shutdown...

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Dont think so,as when cranking - esp on a cold morning the engine would only be turning at 200 odd rpm,too slow to maintain that rpm - so the Ecu would try to inject more fuel to get back up to at least its low idle speed.
It would be quite difficult to check when the injection actually shuts down as the engine stalls,not something you would normally need to know.The only way I can think to find out for sure is to scope the crank sensor and an injector at the same time,then see if it continues to inject all the way down to rest.Td5's must start injecting straight away by the way they fire up so quickly.Mate of mine has a Mack truck out in Oz that you think isnt going to go,cranks for what seems far too long.The Engine Ecu wont allow injection until it can sense oil pressure.Starter motor cheaper than a crank and a set of shells !