https://www.facebook.com/motovatedturbo/videos/460281944775005/?v=460281944775005

We had a D40 brought in with a severe cutting out low power issue while under power and on the road it was horrible, nearly dangerous. First thing we noticed was that the fuel filter looked old externally and with the owner not having a recollection of doing it any time recently we went straight for it seeing as the air fuel ratio went off the scale lean when the issue occurred. We then changed the fuel filter and it was back to normal.... check out the video to see how bad it actually was inside the fuel filter!!!!

Change your fuel filter if in doubt it's an easy cheap item to at least rule that out as a possible cause of an issue.