Misses Under Load

Definition: Steady pulsation or jerking that follows engine speed, usually more pronounced as engine load increases. The exhaust has a steady spitting sound at idle or low speed.
POSSIBLE CAUSE ACTION
Contaminated fuel Drain fuel tank and add clean fuel

Low fuel pressure/Restricted fuel filter/line Test fuel pressure.

Plugged fuel injectors Perform injector service (cleaning). Fuel Injector Cleaning Procedure