Golf 150 TDi NO GTi

[bad dog]

Please can any one help me with a problem regarding a Golf PD 15O
(chipped). Long story...but for a car with 190 bhp its just does not
deliver the goods!. It went into main dealers for new air filter and a
replacement clutch master cylinder and came out a new car, felt like a
fighter plane.......after 2 to 3 weeks back to normal. Please any ideas,
when the cars goes well its a joy to drive, when 'normal' its pants!

[FordyX]

Carbon build up possibly and VW never tell us after the service they have done it. Same thing happened to my 150 TDi

[vwsystems]

it could be a number of things..........

an intermitant fault, turbo or injection problem.....

or it could just be carboned up!!!!!!

in which case try some diesel fuel injection cleaner......
like redex diesel treatment or for something really strong try slick 50 fuel system treatment!!!!