My husband is trying to fix his friends truck. Its a 91 Ram 318...it misses and bucks after its warmed up. Sometimes it completely stalls. It idles okay. Has no trouble codes. He just replaced the fuel pump and filter and tuned it up but the problem still remains. Any ideas??? My hubby is stumped.

 

my buddies 89 ford truck did this, and it was a sheir pin in the distributer was bent, wne a load was put on the motor it would stall, but it would idle just fine.... don't know if this would apply here....

 

I HAD THE SAME EXACT PROBLEM!! Check the ignition coil for spark. If there is none replace it.