Ignition Coils Keep Failing
 

Thanks in advance... new user here. My ignition coils have failed twice. They seem to fail when I take RPMs close to redline. I was getting the 'cam position sensor' error, and learned on this forum that it's usually an electrical issue. All wires and plugs are new. I replaced the coils (and ignition pack) and car ran great. Then, when I got close to redline again, they failed again. Could this be an ECM (PCM) issue? Or a solenoid failing? Thanks!

First off, what year, make, model, engine? What plugs did you put in?

Stop in the new member forum and introduce yourself.
Open the user cp top left and add first name, location, and car to your signature.

That would be good information to have.

Read
https://www.saturnforum.com/forum/new-member-area-9/post-gone-9659/




Remember

In what respect do they "fail"? Misfiring at redline? Misfiring after being at redline? Total loss of spark and car stops running?

Sorry, It's a 99 SL2 (auto)

V Power NGK plugs. All plugs and wires were checked (and replaced). 99 SL2, auto.

After approaching redline, the car was sputtering, seemed to lose about 1/2 power and was struggling to stay idling. It seemed like two cylinders were down. I replaced all plugs and wires with no improvement. I replaced coils and coil pack, then car ran great for a while. Until redline was approached again. Now, it seems the new coils are cooked. Trying to figure out what could cause that.

I don't have a clue. Does this car have a rev limiter by any chance? That would explain the cutting out and missing at higher rpm's, but not the decline of the coils. This is beyond my comprehension as I don't know much about electricity.

Heat? Coil Packs are converting high current low voltage (incoming) to low current high voltage. Along with high current often comes heat. You may be drawing sufficient current at those rpms that the coils are actually overheating to the point of damage. Though you'd think the feed to the coils would be pretty constant. So maybe I dunno.

Yes there is a rev limiter and that explains the sputtering at redline.

Any SES light action after the coils fail? If you actually had cylinders misfiring they would show up as codes.

Gotta ask this -- what is the impetus for running at or near redline?

Derf.. we race it - on an 3/8th mile oval track. I have another Saturn same make (98 tho, not 99) - and haven't had this issue since we've been racing it, 2 years now. Thanks for all your help. If I just try to re-do all the grounds, and replace the ECM, is there a way to reprogram the ECM (to factory)?

Do you get the same cam code error after failure? do you get any other codes after failure, like misfire codes?

From where are you sourcing the coils for the problem car? From where did you source the last pair of coils from the "no issues" car?

They are both second gen sl cars so i wouldn't expect anything different ignitionwise

If I understand correctly from your posts, you replaced both the ignition module AND the coils at the same time. That's two variables at once. So you don't yet know which part is acting up and which is not, or if it's both--or if it is neither

Then there's the issue of plugs. You said you have been running v power NGKs which are copper which is good. Have you tried the stock NGK #BKR4ESA11? The ignition systems on these cars can be finicky.

Also, are the wires within normal spec for a saturn S car (below 12K Ohms)?

I'm not trying to insult your intelligence about these saturn engines but often times it's the simple stuff we forget to consider that is contributing to what seems to be a complex problem

ECMs can be replaced but they need to be "matched" to your car and finding one that is the correct match can be difficult. I don't think that would help since the fuel maps and ignition timing is likely identical....etc

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My reccommendations:

Try a pair of the stock NGKs above, $1.50 ea fr Rockauto

check those wires.

If still misbehaving, I would say the next step is to further reduce the variables.

Ignition module spark test

Swap both suspect ignition modules under a pair of known good coils and see if they are good or if they are the problem. You can perform the ignition module spark test
---remove plug wires at coil towers
---crank engine a few rotations---should produce strong spark between coil tower posts
---have a friend note presence/absence and strength of spark.

If spark on one coil is weak, swap the two coil positions and retry. If the weak spark follows the coil, the coil is bad. If it doesn't the ignition module is bad

If you get two strong sparks then the ign module and both coil packs are good, provided the coils meet the resistance spec below.
The resistance across each coil pack should be 7-10 K Ohms

Likewise do the same with a known good ignition module and swap in your suspect pairs of coils to see if they are the issue.

I am known for my longwindedness -- though uncljohn has me beat by a mile:D. If you don't believe that, search for posts by him......:) but we still love him and he is full of juicy mechanical knowledge you can only get by keeping your hands greasy for 40+ years (Rube's another old timer with greasy hands)

Hope this helps. Trying my best.


As to why the 98 doesn't act up under the same circumstances? Only the Shadow knows......