LS1121

iTrader: (17)

So who makes coils besides OEM and MSD for an LS1? I want to replace my coils but don't want to dish out the price of MSD's.

BigDB

why do you want to replace your coils? if you arnt having a missfire problem then use the money else where. The stock coils have been sufficent for even 1200 HP turbo motors (hot rod proved this with a 5.3 Vortec), if you want an OEM upgrade there is a write up on using the truck coils that have a heat sink build into the casting.

LS1121

iTrader: (17)

I'm thinking of replacing them because I just had the entire top end replaced and it still seems to miss a little. When I am sitting at idle I can feel a little miss or sputter if you will. I don't get any codes but they are the only thing i can think of.Everything outside of the pistons and block are new.

cookba

iTrader: (10)

dont waste money. check your plugs and wires and coils. there is no point "upgrading" the coils at your power level. if anything just replace the one that went bad.

LS1121

iTrader: (17)

I don't know which one is going bad.

thunderstruck507

iTrader: (18)

Any shop with a scan tool should be able to read misfires.

X-ray

iTrader: (6)

Well if you do end up replacing all the coils, go with the GM truck coils. MSD coils are garbage. Upgrading the coils won't improve your performance though.

LS1121

iTrader: (17)

The engine is not throwing any codes. it just has a little miss at idle, I can feel is stumble and hear it miss but when I am hitting the gas it is fine.

lady3bglover

iTrader: (3)

Listen, I just went from a 5.3l to Ls2 and I'm using my same stock coils, which have 169k mi on them. What injectors are you running? And you said topend... heads, what else?

LS1121

iTrader: (17)

Everything except the block and pistons, I made it an 04 Z06. It was doing the same thing before the change. Maybe I will switch the wires and see what happens. I have new plugs. I think I have some old wires some place I can switch them out one at a time and try to isolate the issue.

lady3bglover

iTrader: (3)

Ls1121... PM sent.

LS1121

iTrader: (17)

Thanx I might do that, but I have new NGK iridium plugs.

lady3bglover

iTrader: (3)

Sorry, I'm not a fan of the NGK's... I'd keep those on the side as some spares. JIMO.

LS1121

iTrader: (17)

NGK's were in the link you pm'd me with msd wires??

Paul Bell

iTrader: (9)

Hmmm, most around here use the NGK plugs. Perhaps you're onto something here, what would you use?

I'm using WeaponX.

OP:

"Upgrading" to the big truck coils with the heat sinks may show a little power-or may not-but it will improve driveability and response. However, it's not as easy as pulling the original ones and putting in the truck coils. Harnesses are different, brackets are different and a few things need to be moved a bit. All told it could be several hour's work.

Here's all the dirt on them:
https://ls1tech.com/forums/12985321-post1.html

LS1WS6dreamer

iTrader: (1)

OP have you tried 02 sensors? What NGK's are you running and at what gap?

Nevermind, have you tried some NGK TR55's?

Paul Bell

iTrader: (9)

I would doubt you have a bad coil/wire/plug. If you did, it would be logged as a misfires.

What's the condition of your MAF? Do you still have the screen installed? Often times removing the screen causes more problems than it helps because the airflow hits the sensor at different angles. The stock MAF with screen is good to like 450HP.

Are you using an oiled air filter like the K&N? They've been known to adversely affect the MAF.