This sounds like your fuel enrichment circuit which includes the frequency valve. Do you hear a loud buzzing comming from the right hand valve cover? If not check out the lambda relay and fuse. David Teitelbaum vin 10757 --- In dmcnews@xxxx, AJL521@xxxx wrote: > Hello, > > Since I purchased my D three years ago I have had a problem with the engine > bogging out when the accelerator pedal is at more then half throttle. I've > tried timing, and adjusting the valve in the throttle body, but this has no > effect. Any help that anyone could give would be great. > > Thanks > Andrew > 4194