8 bad coils? Whats wrong???
Thread Starter
Joined: Aug 2005
Posts: 306
Likes: 0
From: Chelmsford, MA
8 bad coils? Whats wrong??? My car is throwing codes p0351 through p0358. These are "Ignition coil X primary/secondary circuit malfunction". The car misses noticeably between about 1000rpms and 2000rpms, and when under load chatters when I take off in those rpms. Also, the car seems to take a lot longer to climb up the RPM's and just doesnt seem to have the power it should.
What could cause all 8 coils to malfunction at the same time? Cause I know there is no way they could all go bad at once.
Also, I did a plug change 2 days earlier and used NGK TR55's gapped at .055 and I have read that other people have had cars run like crap with these plugs and they switched back to the AC Delco Iridiums and that solved the problem, but they didnt throw any codes for coils or anything for that matter.
I already checked the ground on the back of the drivers side head and tis good, so what else could be the problem??? I was thinking that maybe all the coils as a whole are not getting enough voltage, but I dont know where to start looking...
Thanks in advance guys
-Scott
What could cause all 8 coils to malfunction at the same time? Cause I know there is no way they could all go bad at once.
Also, I did a plug change 2 days earlier and used NGK TR55's gapped at .055 and I have read that other people have had cars run like crap with these plugs and they switched back to the AC Delco Iridiums and that solved the problem, but they didnt throw any codes for coils or anything for that matter.
I already checked the ground on the back of the drivers side head and tis good, so what else could be the problem??? I was thinking that maybe all the coils as a whole are not getting enough voltage, but I dont know where to start looking...
Thanks in advance guys
-Scott
It's not the plugs. NGK plugs are used without problems by several of us. Make sure all of the plug wires are connected to the plugs & coils. If you don't hear & feel them snap into place, they are not connected. Did you confirm the gap on all plugs to be .055"? What are your mod's.?
Thread Starter
Joined: Aug 2005
Posts: 306
Likes: 0
From: Chelmsford, MA
Yes I checked the gap on the plugs. I have a lid and debaffled ram air and a spec stage 1 clutch. All the plugs are connected.
Its definitely something before the coils, not after. I think its something electrical but I would have nooo clue where to start looking...
Its definitely something before the coils, not after. I think its something electrical but I would have nooo clue where to start looking...
Have you had the coils unplugged from the main wiring harness for any reason? Maybe for an intake swap? If so, check to make sure the main plugs connections going to the coils are snapped in all the way. Its easy to miss that little detail....
Thread Starter
Joined: Aug 2005
Posts: 306
Likes: 0
From: Chelmsford, MA
I think I just figured out the problem.
Bare with me here but here goes:
This problem started the day after I did a plug change to NGK TR55's. The gap should have been .055 out of the box, which is acceptable for this engine. Now, my car is stock except for a lid. What I was thinking, is that if the gap is wrong on all the plugs, or if the car just doesnt like the copper plugs, then the wrong spark, or lack of enough spark in all the cylinders wouldnt cause a true misfire, but would be enough for the low RPM skipping, and would compensate at the higher RPM's. Now, as for the coils reading as bad, I was thinking that because the computer has no way of really reading the plug itself, it would just assume that the coil is malfunctioning, because the plug IS sparking, but just not enough, so the computer will think that the coil isnt sending enough voltage to the plug.
Enough rambling for now as I am at work, but I am switching back to the AC Delco Iridium plugs tonight and will let everyone know if it solves the problem.
-Scott
Bare with me here but here goes:
This problem started the day after I did a plug change to NGK TR55's. The gap should have been .055 out of the box, which is acceptable for this engine. Now, my car is stock except for a lid. What I was thinking, is that if the gap is wrong on all the plugs, or if the car just doesnt like the copper plugs, then the wrong spark, or lack of enough spark in all the cylinders wouldnt cause a true misfire, but would be enough for the low RPM skipping, and would compensate at the higher RPM's. Now, as for the coils reading as bad, I was thinking that because the computer has no way of really reading the plug itself, it would just assume that the coil is malfunctioning, because the plug IS sparking, but just not enough, so the computer will think that the coil isnt sending enough voltage to the plug.
Enough rambling for now as I am at work, but I am switching back to the AC Delco Iridium plugs tonight and will let everyone know if it solves the problem.
-Scott
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