I have a vauxhall corsa 1.7 cdti 5 door. 2009 model. problems are (and not all of the time) On tick over engine hunts, drops to 800 rpm then up to 1000 rpm, On acceleration engine hesitates, putting my foot down hard on accelerator brings up the symbol spanner through car. When driving say at 60 mph engine hunts, accelerates then slows down, this happens quickly. Fuel filter replaced, Had a service. The car can go for a week or two without any problems, then I can get a week of the problems I have listed.
6 months ago symbol spanner through car came on Vauxhalls said glow plugs at faults, replaced.
Last week engine was hunting, no warning symbols came up on dash, took straight to garage, they suggested changing fuel filter, as it was last changed 2 years ago, This has made no difference.