I can understand the fuel level being caused by this Tom85, but why the bad running ?

Loss of pressure due to short disfunction of pre-pump?

Easy or hard fix Tom85 ?

Hmm, when i think about this, does this happen only during short period after say (1000-1200) revs and then stops? Does this hapen whenever you press the accelerator pedal lightly?

If you press the pedal lightly the car will move off nice and smooth, if you press it hard/quickly it judders as though misfiring at about 900rpm and will stall if i dont take my foot off the pedal.

If the head gasket has been done, it will have had the timing belts of.
Could be that the timing is out by a tooth.
This could cause the problem you are saying as the whole timing of the engine is out.
Check it soon as it could be destructive!!!!!!

SC

How come it runs smooth when its above 1200 rpm heyskull ?

Please please please , really need help with this.

I would bet it is the injector seals. Very easy to do, I assume it is mechanical injection, had this issue on a 2.0 ltr but the 2.3 ltr is just the same, there are two injector seals on each injector if I remember correctly, one 10mm socket size bolt on each injector that holds them in, should take no longer than an hour to fix. Your problem is air getting past the seals.

Cheers
Stephen

Thanks for the advice everyone, going to try all of the above, one at a time and see which does the job.
Gonna ring GSF and see how much for parts in the morning, crossed fingers over the price.

Again, thanks to all
Phil