Steveyg

Good luck! Yeah there wasn't any visible water damage from looking at the ECU, so if you take it out, it may not look like there's anything wrong.

I did mate, yes. Should have posted but it was a good while after. Turned out to be water being washed down on top of the ECU and getting into the multi-plug (sat underneath the windscreen scuttle, good job Skoda!) Wound up greasing it to high heaven nad putting it into a freezer bag.

Spoke to mechanic and apparently the connection to the sensor was all good. I do have the undertray. I'll see about the wires from the plug to the ECU. Cheers!

Hi mate. Thanks for the reply. Could well be, but I'd have assumed that while the crank sensor was being replaced they'd have checked the connection. I will double check though. I would think it's gotta be something maybe just on the outskirts of the sensor since it looks like the sensor itself is sealed up pretty tight in there. Cheers.

Hello mate. I recently had my camshaft sensor replaced. Before, it always started fine cold, then struggled for 2 seconds or so when hot. After replacement it was 2 seconds or so every time. Turns out the aftermarket sensor was giving an inverse magnetic reading. After swapping out for a genuine VW sensor whilst trying to fix my issue, starts straight away every time. Just a thought.

Hey guys. First post but I'll try to be as brief and informative as possible! Having a real nightmare with my Octavia mkII 1.9tdi ('57, 140k on the clock) Right so this is ONLY happening in the rain. When driving engine simply cuts out, no stutter or struggle. Just like turning off the ignition. After a few minutes it will crank over and fire and then run fine. Maybe for 5 seconds, maybe for 20 minutes. I never know! Took it to the garage after the first time this happened and the diagnostic came up with the Camshaft position sensor error. Camshaft was replaced (along with the cambelt because may as well right?) Next time in the rain, cuts out. Same as before. All kinds of dash lights flashing sporadically. Back to the garage and fault codes read. Camshaft position sensor again. The auto electrician was in this time so he checked it out. The camshaft and crankshaft sensors were giving good readings individually but there was a problem with the reference between the two. This turned out to be because the aftermarket camshaft sensor was giving an inverse signal. Replaced for genuine and all reading perfect. This happened to fix the hot start issue by the way! Next time in the rain, had another problem. This time the car started juddering quite severely, like it was misfiring, after maybe 5 seconds of this the tachometer dropped to zero as if the engine wasn't running, 3 lights came on (Oil pressure, TCS, Preglowing), then juddering stopped and I had power as normal while still showing 0 on tachometer. I don't know how long I could drive like this as I decided to stop as soon as safely possible and shut the engine off for a bit. Couple of minutes later it started straight up no problems and I could finish my journey. Back to garage, codes read. Crankshaft sensor implausible signal (P0321) and Glow plug cylinder open circuit (Lost the code) Crankshaft sensor replaced. All seems well until about 2 weeks later when I'm in the rain again and the exact same juddering problem occurs as above. Manage to get to work. On the way back, I get the same old cut out from nowhere, pull over and wait a couple of minutes, started up fine, pull away and immediately get the juddering problem exactly the same as the first time. Pull over and wait a couple of minutes, starts fine and gets me home no problem. Back to garage, fault codes read. Cranshaft implausible (P0321) and Glow plug cylinder 2 open circuit (P161B) And that's about it really. During this time we've had the ECU out and checked for any water ingress for which there was no evidence. Sealed it back up, silicon, greased up the plugs. Doesn't appear to be any water hanging about in the windscreen scuttle. We've also checked starter motor wiring looms, checked all visible looms and multi-plugs with no sign of water/damage. Fuse box under the bonnet has been bone dry every time. There are two multi-plugs I've noticed that seem to get water on them. One in front of the fuse box and one behind the passenger side headlight. This always takes between 20-45 minutes to initially happen on a journey and SEEMS to be dependant on the heaviness of the rain. I have been on 30 minute journeys in light rain with no trouble and 20 minute journeys in heavy rain where it's happened. Logically, since it's never happened when the road itself has been relatively dry and it still takes 20-40 minutes into the journey even when the car has been sat in the rain stationary for hours, I have to assume it's water coming up from the road that's causing the issue. Any ideas? And thanks in advance!