Starting issues

[Craig1982]

Hi guys,your knowledge would be appreciated as I'm new to these cars.i have a fiesta st150 2006.when the engine is warm and I go to start the car it takes about 5 seconds to fire up and the revs are low but clears instantly.it starts straight away with no problems when cold..I find that if I turn the ignition on and pump the throttle peddle a couple of times before starting it that helps but not all the time..yesterday I jumped in the car in a rush with the engine warm and tried fire it up straight away and was lumpy and a message came up on the dash saying something like engine management failure..I switched it off and started it again and it was fine..it has a k and n induction system on it so I'm unsure if it's fuel and air issue??  Thanks in advance

[btmaldon]

When were the plugs last checked/changed? If plugs are new the gap may be too big.

Has your induction system got a cold air feed?