Problem started 4 days ago, noticed on 2nd gear take off from dead stop at a traffic light. Engine bogged down, sounded like it was going to stall then idled back to normal. It did this several more times in a row. Had to start out in first gear. I have noticed an over all slight power loss as well.

Changed fuel filter, thought all was well then it started again. It is not a constant problem, sometimes it will take off fine and then sometimes it will bog down. Just doesn't feel like it has the performance it once had. Engine idles fine and constant at 790 rpm and there are no codes. Also checked oil level and it is fine not fuel diluted and not any more exhaust smoke than normal. Bumped engine over and lift pump comes on so I know thats working and engine isn't making any unusual sounds either. This one has me puzzled. Any of you all have any ideas? Truck has 47K on the odo.

 

lift pump MAY be intermittent, mine was. and that could possibly be why it is only every once in a while