Chevrolet Repair: 1990 chevy silverado 1500 350v8, spark plug wires, chevy silverado

Question
When I am excelerating my truck starts hesitating and pulsating.I changed fuel filter and did a tune up. what could it be

Answer
It could be several things. If it's ignition related it could be misfiring. - Possibly defective spark plug wires, distributor pick up coil,distributor cap and or rotor. Or a cracked or defective spark plug.

If it's fuel related it could be a fuel pump that is weak or an injector that's cutting out intermittently.

A worn EGR valve possibly. Try disconnecting the vacuum hose, plug and road test.

If you give me more info on what exactly it's doing I may be able to help more. Does it idle good? Does the hesitation clear up at cruising speeds? Is it only on accel from a stop?