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Misfire?

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Old Jul 23, 2025 | 04:11 PM
  #1  
Andreas_91GTA's Avatar
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From: Stockholm
Car: Trans Am GTA 1991
Engine: L98 with Super Ram and Fitech
Transmission: 4L60E
Axle/Gears: 3.23:1
Misfire?

So, when starting the car with a hot engine - for example you drive to the store and pick up something in 5 minutes and then back to the car - my engine sometimes misfires. Not running on all 8. It sounds like it has a big cam (it actually sounds really cool) and the exhaust smells of raw gasoline. If I then turn it off and immediately back on it goes away. Plugs are fresh, wires seated firm, no vacuum leaks (to my knowledge). What would be your best guess? It's clearly ignition related.
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Old Jul 23, 2025 | 07:30 PM
  #2  
ughmas's Avatar
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From: Mint Hill, NC
Car: '90 Formula '88 GTA
Engine: 305 TPI 350 TPI
Transmission: T5 700R4
Axle/Gears: 3.42 10 Bolt 3.27 9 bolt
Re: Misfire?

Originally Posted by Andreas_91GTA
So, when starting the car with a hot engine - for example you drive to the store and pick up something in 5 minutes and then back to the car - my engine sometimes misfires. Not running on all 8. It sounds like it has a big cam (it actually sounds really cool) and the exhaust smells of raw gasoline. If I then turn it off and immediately back on it goes away. Plugs are fresh, wires seated firm, no vacuum leaks (to my knowledge). What would be your best guess? It's clearly ignition related.

The ignition control module and pickup coil would be my first suspects. start drilling down the ignition components starting with cap and rotor, get the ICM tested or swap it, check the condition of the pickup coil, the pigtail wires and coil itself can get very corroded and essentially fall apart.
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Old Jul 24, 2025 | 12:59 PM
  #3  
Andreas_91GTA's Avatar
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Joined: Jul 2022
Posts: 146
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From: Stockholm
Car: Trans Am GTA 1991
Engine: L98 with Super Ram and Fitech
Transmission: 4L60E
Axle/Gears: 3.23:1
Re: Misfire?

I'll check the distributor one extra time. But, what boggels me is that the problem only occurs when starting a hot engine, never a cold.
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