no power when engine is warm
 

hi all please could anyone help after ive stopped the engine for about ten minutes set off again theres a loud whooshing noise and no power then if you floor it it seems to cure it have a bailey dump valve could that be the problem also due for a new fuel filter any ideas thanks

dump valve is leaking on part throttle, stronger spring, or better still a recirc valve. The standard valve is pretty good.

thank you