P0304

[98_green_z71]

I'm pulling a misfire on cylinder 4 I have the 5.7 I changed to a mpfi and I have spark to the plug, what else could ve the issue?

 

[Tommy1234]

Could be the wires for the Ignition I don't know if it's a distributor edition vehicle or not. Maybe the distributor cap and rotor.

 

[TreeGeared]

Plugs and wires are the quick easy thing to check. Assuming from your screen name that you have 98 which should be the old spinny type ignition. Remember you need fuel, air, spark, and squish (compression) for everything to work as it should. Think about that as you go through your diagnosis and the culprit should show itself.

 

[JOHNGAAA1]

Gmt 400's are notorious for burning up wires, burning a hole through the cap, spun rotor, shorted cap, etc.