A3 ignition problem

[olski1975]

Hi there,
My '99 A3 tdi has started behaving strangely - I think the problem is related to the ignition but not sure...

I noticed that the glow plug light does not always come on when you turn the ignition on & it sometimes takes 2 or 3 attempts for it to appear - is this simply a glow plug problem?

The other thing that is happening which I think is related is that the car runs fine when just driving along but when I put my foot down it basically bunny hops in a very jerky fashion. This only seems to happen in cold weather and can often come on when on a motorway drive. When I come to a stop the tickover is very lumpy but resets itself as soon as you turn the ignition off & then restart. It only seems to be cold weather that causes this & it otherwise runs fine when I put my foot down.

Any suggestions??