Hi, I wonder if anyone can help. Scudo 1.9 non turbo. 54 plate only 41000 miles. Doesn't cruise smoothly on a constant throttle position, typically there is a background hesitation that clears on full throttle. The van is down on power when going up hill even when it is empty! Lets out occasional puffs of white smoke but not when under full throttle. Is this an injector problem? If so can they be cleaned or is it replacement these days. Van starts on the button and generally drives well. It has had an easy life with periods of little use, probably why something is gummed up. EGR? Any help would be really appreciated. Thanks