fouling plugs

[joienitro1958]

2007 merc efi. Fouling plugs started cylinder 2. gravitated to 2,4 now just recently 2,4,6. Anywhere from 15 minutes to 2 hours running time.. Engine had been hot prior to me buying. New power head, injectors 2,4. New thermostats, fuels pumps, coils 2,4,6. Computer??

[johnmiffco]

check all coil ground wires,wires from switchboxes to coils and ohm out the switchboxes
weak spark will do this on 1 bank,,,,,,,,,2,4,6
can swap switchboxes and see if 1,3,5 starts fouling,,,and other side cleans up

[rock]

Hi Joe. Welcome to the site. Spoke with Hal this morning and found the ecu I sent you a pic of will not work on your motor. Above advice is good. Good luck.

Rock