Hi, My focus has started having a problem where it runs lumpy,the symptoms I have are:

Fuel Gauge is inaccurate and only moves between 1/4 and 1/2

When petrol tank is fuel the car feels like it's holding back above 5,000 RPM

When petrol is low the car won't gain any power when starting uphill and just limps, this also happens when driving normally and can be difficult to start.

Any ideas as to what the problem is would be appreciated.