i have a 2003 150 4.2 -66,000 miles i shut it off came out 1 hour later it started but ran terrible and still is. checked for codes -no codes--------pulled off wires at coil pack #3&#4wre dead - replaced coil pack ------no change---ohmed out wires all ok--replaced plugs no change--- still no codes--today put a timing lit on all the wires--- now the spark is erratic i mean fast - slow fast -when using the lite - help guys next step i was leaning to the pcm.

 

help any ideas