Cambelt tracking

[caprighia22]

Hi All
Great forum, glad I stumbled across it
I am in thr middle of a cambelt change on my 2001 2.0 petrol V40. Fitting a Conitech belt and INA tensioner and pulley. I didn't change the water pump (only done 85k) and I did the cheaters method on the belt ( no locking tools, slipped belt over harmonic damper pulley)

I got everything lined up perfectly in center of all pulleys and the tensioner, set the mechanical tensioner as per procedure , barred engine over. But as soon as I fire the engine the belt walks from the centre of the cam sprocket and tensioner to the rear. The old one ran in the centres. I had the belt off 4 times, and redid tension another 5 or 6 time. Every time the same, belt walks to the rear of the sprockets. I put the old tensioner back on as was a little concerned with new one as its a bit sticky/jerky when setting but same thing happens with old one.

Done a fair bit of searching online and seen a few people mention something similar but not seen anything which resolved it
Any suggestions, its driving me mad !
thanks