1.9 DG WBX Running Problem

Hi, new to the forum and T3 Ownership.

We have had our camper since last year, used it approx 5 times. 1st trip 300 miles it ran perfectly. Used it around town a couple of times then it sat over winter but was regularly run while stationery. On our first trip this year into Wales we got half way and stopped off for lunch, then when we restarted the journey it misbehaved.

Under load in higher gears there was misfiring and no power, dropping into 3rd for a hill or to exit a corner seemed to work, after pulling over it revved fine when not in gear and pulled away fine in 1st and second. I could build the speed up slowly, just seemed to die when pushed harder, as thought the second choke seemed to kill it off.

On the a*** clenching journey home it did the same until after a few 3rd gear higher rev hills it ran perfectly and flew home (as well as you can expect a 2.5 tonne block sapped van too).

Until this week we hadn't used it but decided a trip to work was a good idea.... first sight of a gradient it misfired and chugged again, into 3rd.... nothing, dash lights came on  

It eventually restarted and we made it to work.

Suggestions welcomed, don't really know where to start.

cheers
Rich

Fuel filter? 

Had a similar problem with a DG on a Pierburg carb. I traced it to some contaminate in one of the carb jets. Flushed it with carb cleaner straight down the jets and it worked great - for a bit! It started doing it again, so removed the carb, split it and cleaned them out properly and it was fine after that.