Hello there my car has suddenly out of the blue developed a fuel injection failure. when the car has been stationary for quite a while this problem goes away, only to return again after about 15 mins of driving.

The symptoms are the engine sounding sluggish, shuddering, engine cutting out whilst driving and also cutting out in low revs/low gear.

I have been told that if I use redex or such like then this should clear it?

If there is anything I can do without the need to go to a garage I would greatly appreciate your advice as I have been ripped off big time in the past.

Also I had my car put through an mot just 3 weeks ago, surly this problem should have been found then??