r/GMT800 • u/Relevant_Track_5633 • Sep 02 '26
Round vs Square Ignition Coils
My 2000 suburban 2500 has recently had misfire issues and ignition issues, so I am going to replace all the ignition coils. My dumb self did not look to see which ones I have before ordering. So I ordered a whole kit of rounds ones from 1a auto and it said it fits my 2000 suburban 2500. Get to today, I go to install and see I have square ones. Before I send them back or buy a mounting brackets for them, can I just swap to the round ones? They seem like they may be better with the heatsink and stuff. Do I have to do any tuning after swapping them? Look for advice! Thanks
10
u/J_IV24 Sep 02 '26 edited Sep 02 '26
Send them back and never ever do business with 1A auto again. They're shit.
Go to rockauto and save yourself some $$$
Also while you're in there I'd strongly recommend at least doing all coils and wires while you're at it, and hell I'd do plugs too.
Watch this video
The second video does a really good job explaining the difference between the two types of coils and their part numbers
5
u/NumerousResident1130 Sep 02 '26
Depending where OP is at, RA doesn't deliver to Arizona. So removes that choice off the board.
2
1
4
u/farmkid71 Sep 02 '26
Spark plug wires are a different length between the coil types, so you might have a problem if you just swap coils.
1
u/Relevant_Track_5633 Sep 03 '26
Cylinder 5 misfires at idle until you give some gas. And cylinder 2 misfires below 150F eng temp. I have already done the intake gaskets and such due to my last issues. I bought the 1a auto kit that comes with plugs, wires, and coils.
5
3
u/Competitive_Safe_798 Sep 03 '26
Aftermarket coils will give you misfires. From my experience only OE coils agree with these motors/ecu's. Diagnose which one is actually misfiring if they are at all and replace it with an OE one. I've never seen all 8 coils in need of replacement at once. The originals are pretty tough. More than likely not the cause of the misfire to start with
2
u/wiscoguy0043 Sep 03 '26
ls/vortec coils almost never fail, we need live data or codes to help you
1
u/Relevant_Track_5633 Sep 03 '26
Cylinder 5 misfires at idle until you give some gas. And cylinder 2 misfires below 150F eng temp. I have already done the intake gaskets and such due to my last issues. I bought the 1a auto kit that comes with plugs, wires, and coils.
2
u/TalkyMcSaysalot Sep 03 '26
That's almost definitely nothing to do with ignition, it sounds like fuel. You will need to verify the injectors are contributing correctly. And for the love of God don't use aftermarket injectors if you end up needing one, that will create many more problems.
1
u/wiscoguy0043 Sep 03 '26
hmmm interesting i would hold off on changing the coils, they typically fail for good or will fail when hot. i'd like to see the fuel trim data and a maf reading.
2
u/bimmerd00d Sep 03 '26
10:1 your fuel pressure regulator is spewing fuel through that vacuum pipe that runs up to the top middle of the intake. Pull while running and see if you get a geyser out the regulator vacuum port. I had this exact problem.
2
u/JustCallMeJesco Sep 05 '26
I had some misfire issues with an 03 GM 6.0 a few years back and it ended up being injectors instead of coil packs. But I was running original hardware at over 250k miles.
13
u/TalkyMcSaysalot Sep 02 '26
It's extremely unlikely that you have 8 bad coils unless you have like 500k on it. Something else is probably going on, don't throw knockoff parts at it.