Coil pack test - Is there an easy way?

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

EddieC

Full Access Member
Joined
Aug 9, 2014
Posts
649
Reaction score
513
I used to fix things that weren't broken and often made them worse.
I learned to get past that habit.
I guess if I had spares I wouldn't worry about their condition until I needed them which seems to turn out to be never for me.

As a followup, my original coils are 16 years old and have not been a concern.
 
Last edited:

strutaeng

Full Access Member
Joined
Aug 10, 2023
Posts
1,190
Reaction score
2,480
Location
Dallas, Texas
some info.


while you might be able to fire the coil in open air, you can't really test if they will fire a plug properly under load that's why it's standard practice when getting missfie code to swap the coil with another cyl. to see if the miss follows the coil.


not saying old guy us right, but they do kinda fail more often than what old guys are used to. it could purely be the odds of it happening is higher with 8 than one. or we seem to have gone backwards in quality parts wise. old coils might just have been better. I had a 96 with 325k when I sold it.. still on the oem coil. I got my 2011 with 130isj on it and it's already had one changed out.

now that said, the ls coils are very much more complicated. lots of electronics to fail in them. old coils are mostly just a transformer. ls coils do put out more spark power too.
Interesting, I thought these coils are the same: just a copper-wound (or aluminum?) transformer, no different than the older ones?I've never opened one up...but probably just windings.

What electronics are you talking about?

The SBC Vortec are notorious for having the ignition control module fail. The standard procedure is for guys to replace the ICM along with the coil. Coils are probably okay, but you know the parts changer mentality: "oh, I'm going to replace it since it's got *** miles." The ICM has that thermal paste, and a lot of guys blame that for failures; I don't know if that's true TBH. Most will recommend having an extra ICM in your glovebox in case you are need it, along with a cap and rotor because it's failed on them at least once. I'm glad that system was phased out because in my experience, a failure will leave you stranded: engine completely dead. And aftermarket replacement parts are notoriously poor quality, which doesn't help either.

A failure in an LS coil and you can at least get off the road with a misfire. The ECU doing the switching internally I guess replaced the ICM (?) Very rare for ECUs to fail. If anything, I think the LS are way more reliable on this aspect, but it's okay if you disagree.

The 8 coils having more power than 1 is more like a performance thing.
 
Last edited:

j91z28d1

Full Access Member
Joined
Feb 28, 2022
Posts
3,097
Reaction score
3,824
Interesting, I thought these coils are the same: just a copper-wound (or aluminum?) transformer, no different than the older ones?I've never opened one up...but probably just windings.

What electronics are you talking about?

The SBC Vortec are notorious for having the ignition control module fail. The standard procedure is for guys to replace the ICM along with the coil. Coils are probably okay, but you know the parts changer mentality: "oh, I'm going to replace it since it's got *** miles." The ICM has that thermal paste, and a lot of guys blame that for failures; I don't know if that's true TBH. Most will recommend having an extra ICM in your glovebox in case you are need it, along with a cap and rotor because it's failed on them at least once. I'm glad that system was phased out because in my experience, a failure will leave you stranded: engine completely dead. And aftermarket replacement parts are notoriously poor quality, which doesn't help either.

A failure in an LS coil and you can at least get off the road with a misfire. The ECU doing the switching internally I guess replaced the ICM (?) Very rare for ECUs to fail. If anything, I think the LS are way more reliable on this aspect, but it's okay if you disagree.

The 8 coils having more power than 1 is more like a performance thing.


each ls coil a 100% has electronic circuits in them. they are not just coils like back in the day. they get more complicated the newer you get too, Google ls smart coils for info on that stuff. the best place to learn what it takes to fire ls coils is going to be the megasquirt message boards, they will have diagrams and stuff for you.


again, which is better? we aren't going to even go back to one coil and dizzy. but I will say this, when a obs loses spark you can fix it in a parking lot for cheap by replacing 2 or 3 parts from any parts store. an ls ign starts messing up there's pages and pages of trying to fix random misfires and nonsense. it might be better but it's definitely not more simple. but same could he said for a carb.
 

strutaeng

Full Access Member
Joined
Aug 10, 2023
Posts
1,190
Reaction score
2,480
Location
Dallas, Texas
each ls coil a 100% has electronic circuits in them. they are not just coils like back in the day. they get more complicated the newer you get too, Google ls smart coils for info on that stuff. the best place to learn what it takes to fire ls coils is going to be the megasquirt message boards, they will have diagrams and stuff for you.


again, which is better? we aren't going to even go back to one coil and dizzy. but I will say this, when a obs loses spark you can fix it in a parking lot for cheap by replacing 2 or 3 parts from any parts store. an ls ign starts messing up there's pages and pages of trying to fix random misfires and nonsense. it might be better but it's definitely not more simple. but same could he said for a carb.
Carburators? That's WAY before my time, so I can't argue about anything carbs. Heck, my Dad hasn't even owned a carbureted vehicle since the 80s.

Where do you see that there's more electronics here? It's looks about the same to me. I'm obviously comparing the two generations of the same timeline (one generation back vs one generation forward and of course things change more) Guys throwing parts at trucks is simply because lack of diagnostics knowledge. Both parties are guilty. I am as well in my younger years (my SBC years). I have no shame in admitting that. My dad was never a gearhead and I've learned this myself, out of necessity.

But agree with you reliability (throw power and emissions in there) vs simplicity. You can't have your cake and eat it too....so I digress.
 

Attachments

  • IMG_20240909_160812457.jpg
    IMG_20240909_160812457.jpg
    692.5 KB · Views: 5
Last edited:

j91z28d1

Full Access Member
Joined
Feb 28, 2022
Posts
3,097
Reaction score
3,824
I still work on carburetor at work. you can order rebuild kits thru napa of all places haha.

I don't know why you keep fighting about ls coils lol. here's a schematic, just takes 2 secs to Google how they work.you can also cut an old one open, almost every stand alone coil these is more than a simple transformer like old coils do. (high end import stuff is wild) you can't even fire a ls coil with a old Gen 1 ecm without a control box inline. for years guys wanted to use coils on sbc tpi cars and you just can't, even trying wasted spark. there's no way to get a obd1 ecm to output the squad wave needed to tell the coils to fire. the smart coils can even measure the amount of power used to fire the spark plug based on all kinds of stuff. that way they become a "sensor" to help you diagnose cyl pressure.

Screenshot_20240911-200020.png
 

Forum statistics

Threads
132,364
Posts
1,866,745
Members
96,985
Latest member
LeanMachine
Top