SOLVED:Idle Problem

[Grant]

Lambda would only explain rich running and even if you got rid of the fpr completely, it wouldn't over fuel that much. It only returns a tiny amount of fuel.

If the FPR us stuck open or the diaphragm is compromised it will be over fuelling plenty enough to explain the symptoms Sam has described. You know full well the pressure those things have in them, after mine nearly embedded itself in your forehead! Lol. They regulate to 3.2 bar (yes?) whereas the pumps pump at over 4. If there is nothing regulating that pressure of course it will be over fuelling enough. Up to and possibly beyond 1 bar too much.

Not saying its certainly this, but it from the problems Sam has described it sure does point to it.