tddi fuel faults

[bozza]

hope someone can help,got a connect tddi that starts fine hot or cold,somedays runs fine somedays cuts out,feels like its running out of fuel,but will start up no probs again,
when it restarts it will tickover ok but not run above 1000rpm,if i restart with foot flat to floor it will start and rev above 2000rpm, but if i let revs drop it splutters and stops,it just doesn't want to run between 1000rpm and 2000rpm.
no fault lights showin when it stops.
changed the fuel filter and crank sensor.