Joe, I think David T. and John H. are on target saying it is electrical in origin. Also, I tend to think that your problem is probably more apt to be ignition than fuel related. Once my car is fully warmed up, I can unplug the frequency valve and it still runs fine (just a little too lean). I learned this by debugging a bad lambda relay. If your problem persists even when the engine is fully warmed up, then based on my experience with my car, I think it isn't likely to be the lambda system. I suggest checking the electrical connections around fuse #7. I think you might be loosing spark from a weak fuse connection, bad plug wires, coil or whatever. Walt Tampa, FL -----Original Message----- From: Joe Palatinus <jpalatinus@xxxx> >While driving I occasionally get a jerking, or jolting, or not smooth >accelerating. I feels like its not getting gas, and then I press on the >gas and it goes rapidly, or accelerates very rough.