I have a 1996 F150 (4.9 auto) with 38k miles. Last week I noticed the truck would buck every so often driving at steady speed, I first thought it was just a bump in the road. It has progressively gotten worse to the point it will buck if I press the pedal 1/4 the way down every time. The truck idles fine and revs fine in park. If I put truck in gear and brake torque it slightly it will buck and miss.
So far I have replaced dist. cap/rotor, plug wires and fuel filter. Plugs are 4 months old.
I have unhooked the EGR vacuum line (which had vac when unhooked ?) and plugged, have sprayed all intake and throttle body gaskets trying to find leaks, have added injection cleaner and sea foam to both tanks. None of the above have had zero effect on the issue!! Also have no codes.
I have read many post on what seem to be the same problem I am having. Many have seemed to have had good luck with plugging off EGR with blank gasket. But they also seen a differance when unhooking EGR vac line,which has no effect on mine!
I think I will change out plugs next!!?? I have seen alot of post where people have changed out most of there entire fuel and ignition systems and still having issue.
I am just trying to avoid throwing buckets of money at this with no results!

I have ran out of ideas! Please, Can somebody Help!!!!

Thank You for reading.......EBean

 

Try pulling the codes before you throw anymore money at it.

 

No codes showing up yet.

I think I am going to replace plugs and coil next...

 

One of my "new" autozone plug wires was bad, end was not crimped, it fell out of wire when taking off plug!!
Runs great now!

Thanks all for your time

Bean....