Howdy! From snowy upstate NY... I ran in to a problem recently... the last few days, about 600 miles i've been dealing with dead/weak/erratic spark from a couple of the towers.. It has the 3 coil, 2 towers on each coil, and a Ignition control module. The coil with tower 1 and 4 on it,(top) cyl 1 has a good spark every 1/2 sec or so, cyl 4 is bright blue rapid spark, .. Next the coil with towers 5 and 2,(middle) cyl 5 has no spark, while cyl 2 sparks as expected.. same story with the last coil,(by connector) tower 3 is iffy, while tower 6 is full working spark..
What i did to try to fix this..
I had this i thought same issue 3 weeks ago, replaced the OEM GM ICM, and all 3 coils with BWD from advanced auto, problem fixed.. it came up again, i thought the ICM went out AGAIN, so i changed out the ICM but this time the the miss stayed.. I changed out the coil packs again, same story, changed the spark plus, and even the CSPS, checked grounds, battery has 13.X with engine off, 14.5V engine idling... and its still missing....
now this miss stated off real weak, as it would only miss say passing at 65MPH, then it just stated getting worse.. it at this time is on 3 cyls..
What tooooo doo? HelP!! Thank you much...
What i did to try to fix this..
I had this i thought same issue 3 weeks ago, replaced the OEM GM ICM, and all 3 coils with BWD from advanced auto, problem fixed.. it came up again, i thought the ICM went out AGAIN, so i changed out the ICM but this time the the miss stayed.. I changed out the coil packs again, same story, changed the spark plus, and even the CSPS, checked grounds, battery has 13.X with engine off, 14.5V engine idling... and its still missing....
now this miss stated off real weak, as it would only miss say passing at 65MPH, then it just stated getting worse.. it at this time is on 3 cyls..
What tooooo doo? HelP!! Thank you much...