Another misfire thread! (High RPM)

[SJx408]

I know I know, another glorious misfire thread. I've done some searching and seems like everyone's situation varied slightly depending on where the misfire was. Mine happens up top in the power band. Here's the story +Video :

A group of friends decided to take a trip down to Mexico for some "testing". One friend just bought a stock 65k mile '01 SS and wanted to test it out against my "slow bolt on LT1". Guy says no digs because he's on old 235 tires. "Well why are you racing ? F*ck it I wanna see what it does...ok". 2nd gear 40 roll is my sweet spot. We go at it and just as the tach passes 4.5k I feel a stutter/misfire or that's what it felt like. It felt like it gave some feedback through the gas pedal, and then it evened out. I'm shifting at like 5100rpm on my 150k mile turd. Did it all night same spot about every time. Doesn't backfire or misfire anywhere else. It can do clean pulls from dead stops but once it hits there it loses power.

Hard to guess, plugs and wires have less than 2k miles. Opti has about 10k on it. Has a moe bailey mail order on it and runs and sounds great. Never had it on a dyno though. Let's see, plugs if I can remember were NGK just forgot what type (TR55's I believe). Last time I did them was when I did the LT's and I didn't have them readily available so I had to buy what was in stock at O'reilly, these paired with some no name 7mm wire kit might be the culprit hell idk. I'm sure the vets will chime in. Forgive me for I am a newb with performance stuff. My car just looks pretty

Videos below just for the hell of it.

'01 SS to the left and "blob eye" WRX to the right



'01 SS left and '12 Evo X Right



SS POV





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[Camaro96]

It sounds like you have an idea were to start change plugs, check out plug wires ohms of resistance. When the car is idling dose the tack needle stay steady or dose it move?

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[atlantadan]

What brand opti?

[SJx408]

It sounds like you have an idea were to start change plugs, check out plug wires ohms of resistance. When the car is idling dose the tack needle stay steady or dose it move?

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Tach needle stays still but on cold starts I notice it may dip slightly. I'll definitely check out plug wires as well.


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[SJx408]

What brand opti?

You guys are gonna crucify me for this. It's a "Chandler Motorsports" opti...lol I was broke and needed my car to run (daily at the time) and it was in the budget.


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[Spartan7]

Does it miss all the way to 5100 or just stutter around 4500? Pull a couple plugs and see if they're fouled, and run the engine at night and see if you can spot any wires arcing. Opti is definitely a possibility, but do the easy stuff first.

[SJx408]

Does it miss all the way to 5100 or just stutter around 4500? Pull a couple plugs and see if they're fouled, and run the engine at night and see if you can spot any wires arcing. Opti is definitely a possibility, but do the easy stuff first.

Just a slight miss at around 4.5-4.8 and it's for a split second. It's not a constant misfire all the way up. I'll definitely take a look at the easy stuff first. Thanks for the replies thus far guys.


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[popo8]

You guys are gonna crucify me for this. It's a "Chandler Motorsports" opti...lol I was broke and needed my car to run (daily at the time) and it was in the budget.


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No crucifying... but definitely puts the opti at the top of my suspicions.

LTXtech.com IS my drug...
OWNER/ADMIN

[SSlowBoat]

Opti. Sounds like what my firebrd did with a tired 180k+ mile stock opti.


@SJx408 skip to 1:40

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[SJx408]

No crucifying... but definitely puts the opti at the top of my suspicions.

LTXtech.com IS my drug...
OWNER/ADMIN

That's what I'm thinking. This old girl may go torqhead or 24x in the future but for now opti needs to be 100%


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