95% of the time my car runs fine but occasionaly starts juddering at 30-40mph. You drrve at 60-70 and it is fine but slow down to 30-40 and it jumps about with kangaroo petrol. Also when idling it sometimes appears to stall and loose revs but then picks up again. I have had a new distributor and a new fuel pump but the problem persists. The garage has checked the dignostics but can't find a fault but it is checking when the engine is running fine. When the fault occurs it will judder for a few minutes and then get ovet whatever the problem is and run fine again. It is most annoying. Any ideas. pb

 

have you ever changed the fuel filter? Spark plugs?