Expert: Robert Summers - 11/9/2007

Question
98 z71 350 vortec just change my plugs ,wires , cap ,rotor cause motor vibrates and fast speed and ck engine light comes on showing miss fire on number 3  what is causes this .at idle its normal and normal speeds every thing fine

Answer
Hi William... check to see that you have the firing order right. 18436572. mixing up 3 and 5 would cause that..if ok check to see that you maybe got a bad plug or wire.. change #3 plug and wire to another spot and see if misfire moves to that cyl.. if it does change them...hope this helps