Had a 10 mile drive up the motorway today...car fine for about 6 miles, then all of a sudden the power drops. It didn't so much slow down as just refuse to go faster, felt like someone was strangling the engine.
Sorted itself out within about 5 seconds, but had a few coughs/judders for the next few miles - noticed the LPG/petrol switch was flashing at this point (not out of LPG, at least 1/4 tank or more), it only flashes when it is running on petrol before switching to LPG after startup.
I flicked to petrol on the switch and I did get a judder a few seconds in, but then nothing since.
Drove home through town on petrol, no problems at all. Got home and flicked the switch to LPG - no issues either, it went onto LPG perfectly fine (engine noise changes and you hear the click of the LPG system kicking in). Gave it a good rev and still no problem.
No EML lights on (LPG parts won't set this off anyhow).
Very wierd - I can only liken it to when my old Nova had some muck in the fuel lines which kept blocking the carb jets. If the Nova stalled it would start again fine within a minute or two once the blockage had settled out.
It'll be getting a run to work tomorrow (30miles), so it'll either happen again or not I guess! I wondered if it was perhaps something as simple as some dirt in the TB? It's never been cleaned in 141,000 miles but has not really given me any need to clean it (had the judder on accel twice which has cleared itself within a week or so each time).