Hi all, first post here thanks for having me. My gu4 td42ti tacho is playing up. It was all working fine until yesterday not sure if its a coincidence that I blocked off the egr and gave the IC a clean out yesterday with kerosene then metho.

Now the tacho works fine when car is parked still, soon as I start to even roll out of the driveway it drops to 0 and starts jumping up and down when driving.

Any idea what's going on or where to look?

Cheers