I have had this problem for quite some time. I've been trying to narrow it down one test and one part at a time with no luck.
It will occasionally drive great with no problems but other times it surges while accelerating and driving down the road. I've had the timing checked, replaced the spark plugs, replaced the wires a while back, replaced the EGR valve, and replaced the cap and rotor.
The truck will idle fine except for the occasional rough idle in gear during the times the truck is running badly.
Any suggestions would be appreciated.
Thanks.