the most common cause for this is either a faulty transfer fuel pump or possibbly a faulty accelerator pedal position sensor
1. Check fuel delivery from the transfer pump. The transfer pump should deliver 40 oz. in 20 seconds
I don't believe its the fuel transfer pump...its too violent of a buck and usually with a fuel pump issue you will loose power just before the jerk or buck. My feeling is the throttle position switch, but your diagnosis of the faulty accelerator pedal position sensor sounds sensible. I'm looking into it.... This has been the best answer so far.
After thinking about this for a little while, I'm not convinced that this part will fix it because it bucks/jerks even when the cruise control is being used. Would this point back to the TPS. What do you think?
This truck has been to two different dealers to be tested for this problem. I've even done the Smart Scan Computer test. I will verify with them that all updates have been performed, but I'm going to assume that they have. The question about the accelerator pedal sensor switch being the issue still remains because this truck bucks/jerks violently even when the cruise control is being used. Do you think that the APPSS is still the issue?