What would cause the #3 cylender to misfire

Question

i have a 2003 f-150

Answer 1

spark plug/cable/distributor

Answer 2

It is either spark or fuel, check to see if the plug wire is on tight and if the plug is clean. If all that checks out you probably have a bad fuel injector.

Good Luck!

Answer 3

bad plug wires can do it. look at the tower, where the plug wire goes onto the dist.cap or on the coil pact, it might be corroded.