Hello, does anyone know if there is any form of electrical boost controll or intervention,

i have a 99 T reg octavia 1.9tdi. and twice now i'm driving along and there is a sudden loss of power almost as if dropping into limp mode (no boost), i have no access to vag com so can't scan for faults, and some dodgy so and so has removed both the bulb and holder from the engine management light so dont even know if this comes on

Both times this has happened i have flicked the ignition off and back on and full power is resumed, the last time it happened (this morning) i heard a click like a relay just before it happened from around where my right knee is. i have heard this before but with no power loss, no wipers on or indicators or rear heated screen etc and randomly i will hear a relay click a few times in quick sucsession?

any help greatfully recieved

'99 plate, is that 90 or 110? I am guessing the 110, as I think a 90 of that age would have a wastegate based turbo and not be VNT based.

Was the engine cold this morning? I get a click of a relay around 2250rpm (iirc) which turns on the glowplugs below 2250 and off when the rpm is higher. This happens for the first few (5-8?) minutes until the engine is warm.

Eitherway if cycling the ignition cures the problem it does sound like it is going into limp home mode.

Yeah you really need to get a VCDS/Vagcom diagnostic done or buy a cable & software off ebay.

Thanks, it's a 90bhp version, I shall try to get a dia done on Wednesday as a friend has a full version vag com but lives 20 miles away, hope its nothing to hard to fix, as I am driving to Barcelona in two weeks then back through europe

If yours has a VNT based turbo pull off the vacuum pipe from the n75 valve to the actuator on the turbo and try sucking it, you should get a smooth movement with no creaky noises. That might help to show if the vanes are the issue, or is the problem is else where (such as a vacuum leak).

I might be worth logging actual vs requested MAP too when you can get to your mates.