I'm hoping someones dabbled with a 2006-ish astra and can help ID this problem the one I'm driving around has developed. It's particularly bad when taking off from stand still, and even worse if it's cold. When you let the clutch pedal out and give it an appropriate amount of throttle, it kind of sits there barely moving or revving for a good second or more, then all of sudden the power just surges on and it flies off the line. Same when you go to 2nd gear, it will roll along for a second or so, then power on. It also idles badly on cold days when it is also cold.

Any idea what the problem could be? I just wouldn't know where to start looking. A website I just read suggests maybe the electric throttle body, or even cam sensor - but I wouldn't be surprised if it was fuel pump or regulator related too. It is also due to have the timing belt(?) done , so could that cause such this issue?