Help anybody - have 00 SSEi that has a random missfire hot - SES light flashes in dash but not had code - just says random missfire detected. Have put new Rapidfires and A/c wires on, replaced all 3 coils and tried a new ignition module. Have it a a local shop now and they have got it to do it several times. Cly 2 & 4 dropping off and cat will smell. Bring up boost thought and it will run fine. Any thoughts or suggestions?
Change your pulgs. You don't want Platinum plugs in a supercharged engine. Get a set of autolite copper plugs. They sell for around $1.30 each. That should fix the misfire problem. If your doing any mods on the engine, consider 1 range colder on the plugs.
On an 00+, it is always a good idea to check the fuel pressure. FSM states it should be 48-52psi after 5-10 key on'* with engine off. I usually find the 00+ run light at around 40psi which can cause problems. Have them check O2'* as well, if they stay lean all the time, that'* bad. Although the pcm probably would have mentioned that by now.
Those are actually Napa branded coils or you just got them at Napa? You may want to try a set of AC Delco factory coils. I tried MSD'* for a while and got random misfires at high RPMs. These cars seem to like there factory Coils.
Actually not sure - got them from NAPA - threw them on after it started missfiring - the shop has been working with me. They the an ign. mod at it and gave it back for me to drive. Ran out good for 4 days and then the day I was going back to square up it acted up twice. Has been there 2 weeks now as they drive it on and off.