C5 miss-fire and detonation.....HELP!!
02-17-2013, 10:52 AM
#1
Staging Lane
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C5 miss-fire and detonation.....HELP!! I have a 2000 C5, when I bought it a year ago it came with 6 MSD and 2 stock ignition coils. The problem I'm having is that it sounds like its detonating above 4,000 RPM or if I'm on the interstate and just roll into the throttle it sounds like it starts to detonate. A week or so ago the engine started to miss and the CEL came on, I checked and the code was a miss fire on 7, I pulled the coil checked the wire and spark plug, cleared the code and it happened again a couple days later so I swapped coils on 7 and 2, I got the miss fire code again but it was on 8. If I just drive short distances it seems to be fine but if I drive 25 miles or more it will miss fire or if I'm out running errands it will miss fire after a couple stops. Based on that it seems to be a heat soak thing and the coils is all I can think of. Anyone else have a similar problem or any ideas....THANKS!!
02-17-2013, 12:24 PM
#2
Those MSD coils have been known to cause issues. From what I recall, the consensus on here was to stay away from them.
Personally, I'd grab a good used set of stock OEM coils off here or ebay. Replace the plugs and wires and see how it runs.
If it is intermittent, it could be a coil acting up once it gets warm or possibly a plug wire breaking down. I'd lean toward the coils. I find it interesting that it had 6 MSD and 2 stock ones. It was like someone was having issues with them and swapped on 2 others to replace failed ones.
Personally, I'd grab a good used set of stock OEM coils off here or ebay. Replace the plugs and wires and see how it runs.
If it is intermittent, it could be a coil acting up once it gets warm or possibly a plug wire breaking down. I'd lean toward the coils. I find it interesting that it had 6 MSD and 2 stock ones. It was like someone was having issues with them and swapped on 2 others to replace failed ones.
02-25-2013, 06:00 PM
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FormerVendor
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I have a 2000 C5, when I bought it a year ago it came with 6 MSD and 2 stock ignition coils. The problem I'm having is that it sounds like its detonating above 4,000 RPM or if I'm on the interstate and just roll into the throttle it sounds like it starts to detonate. A week or so ago the engine started to miss and the CEL came on, I checked and the code was a miss fire on 7, I pulled the coil checked the wire and spark plug, cleared the code and it happened again a couple days later so I swapped coils on 7 and 2, I got the miss fire code again but it was on 8. If I just drive short distances it seems to be fine but if I drive 25 miles or more it will miss fire or if I'm out running errands it will miss fire after a couple stops. Based on that it seems to be a heat soak thing and the coils is all I can think of. Anyone else have a similar problem or any ideas....THANKS!!
- Matt
