Recently I have fitted a new carby - cheap factory brand. The car has had a flat spot for some time and I was hoping the new carby would solve the problem. The last time I tuned it by adjusting the float level and idle screw. Car runs well in fourth a bit after 60. Car is not running well in these situations - starting off at traffic lights and will almost stall and starve unless I rev it up a bit first before letting the clutch out. Other times changing from second to third and getting back on accelerator in fourth under 60 and also mainly left cornering. Maybe it is the fuel pump?