[tomerlingall]

Hello Everyone,

I'm new to the forum, so thanks in advance for any time spent looking or replying to this.

I have a 2001 2.5tdi 88bhp T4. Usually the van is kept in my barn but twice recently I've left it out overnight and both times it's rained heavily. The first time the throttle was completely absent from the get go, just a tick over and zero response from the pedal. I googled and looked on here and tried taking the pedal apart to see if that made a difference, it all looked very clean and in good working order. Had a fiddle with the ECU which isn't mounted very well onto it's mount (cable tie ) Then put it back together and bingo the throttle was back! Bit worrying though as seemed unlikely i'd down anything to cure the issue.

Then last weekend I took it away for a course, it was out again over night and the weather was BAD and half way down the M40 in the pouring rain I lost power, but not everything I think maybe it was in limp mode. So I pulled off at the next junction and as I slowed the throttle just lost connection and I drove on tick over to get off the road. Popped the bonnet and fiddled with the ECU and turned the engine back on and bingo throttle back again. Hmmm, not a great sign I thought. I then suddenly lost the throttle about 15 more times over the remaining 30mins of the journey with me turning the ignition off and on each time and mostly the throttle coming back online each time. Also the glow plug light would come on and I believe this is the engine management fault light?

I decided to get recovered home on the sunday and the mechanic plugged in his computer but didn't come up with any diagnostics. He was convinced it wouldn't be damp in the ECU and concentrated on the vacuum system that controls the accelerator..

So I'm at a total loss as to what to do. Any ideas??? I've read that it could be the wiring going across the front of the engine or the ECU or the potentiometer or or or, ahhhhh:*:*

Feels like it could be a rabbit hole of possibilities so any experiences with this problem and pointers would be great. Sorry for long post

Cheers

Tom

 

[JIMMYJAMES]

Throttle potentiometers can fail, i have swapped one ona a van with similar symptoms and the issue went away. Not 100% on this as it could be many things. If you have VCDS you can test the operation of the throttle in measuring blocks in real time.

 

[tomerlingall]

Ok thanks, so would that mean buying a replacement pedal? Would the VCDS show up anything if the van is driving fine at that moment? I'm at a bit of a loss of what to do! Cheers

 

[JIMMYJAMES]

Ok thanks, so would that mean buying a replacement pedal? Would the VCDS show up anything if the van is driving fine at that moment? I'm at a bit of a loss of what to do! Cheers

Is the fault intermittant? How often does it happen?

 

[tomerlingall]

It's sporadic and sometimes resets and is OK again for a period of time after switching ignition off and back on again. The last time I drove it it was doing it every couple of minutes though and I got recovered home, I haven't driven it since. It was wet that weekend and the time before too so I wondered it could be the damp getting in around the wiring somewhere..?