Tdi issue, power drop!?

Hi all, odd problem here...

Whilst driving down the road the car has juddered for a second (definite momentary power loss) and the glow plug flashed at the same time.

Light then goes off and car is normal. It had done this about 4 times in 2 days.

I did a full vagcom scan, no faults. Did some logs and nothing seemed out of the ordinary apart from the vagcom kept crashing saying no response from controller in the middle of running some logs.

A couple of times the readings where conpletley scrambled on vag com, temp reading went from 61 deg to minus 100 and Somthing..... Whats broke now lol!

That was my first thought, had a look and no way water got to it, it's conpletley wrapped in a black bag!

I have a spare ecu from an alh (mines an ASV) and tried it but with that ecu there was no power to the injection pump so I can only assume this ecu will not work on my car. The second ecu has a custom remap and immobi delete on it!

I'm starting to think the problem could just be the brake light switch but that wouldn't explain the lack of communication to the ecu!

Cheers for the help, missed these replies.

The ASV (standard) ecu had severe moisture previously. I removed it, split the caseing and left it to dry out for about 2 weeks, I think I also gave it a light heat up with a heat gun whilst it was apart. Once dried out it seems fine. No issues for 2-3 weeks (previous to that car was off the road). I wrapped a black bag on it myself to prevent water damage again.

The scuttle plastics are not damaged but they have been letting water in somwhere. Is it worth taking them off and sealing the joins with silicone or Somthing?

The alh (from a skoda I think) ecu was purchased online and I don't know the history of it. It was sent to a very reputable tuner (AmD technic) and they had to open the ecu and delete the immobiliser. I think they used some sort of chip for this. They also copied my custom remap from their files to the ecu. They never had my car to test the ecu. When I said no power to the pump I meant fuel system in general. When I try to start the car with the alh ecu there is no glow plug light atall, no sound from the fuel shut off and relay 109 does nothing so getting no power I assume.

It did this again today at about 75mph and only once I hit a big bump on the motorway, this time the tcs light came on and stayed on so I should have a fault code to pull tomorrow. Also whenever the glow plug light flashes the revs drop. Not sure if it would stall the engine but at least a 2-300 rpm drop. As soon as the glow plug light goes off the revs return to normal.

Recon it's worth asking them to retest it!? I could send it back to them again!!

Will have a check, once I get them all il post them up