85 Corvette occasionally stutters under acceleration
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Instructor
Joined: Jun 2024
Posts: 126
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Replaced all the plug wires and wiped all the dielectric residue off the spark plugs. It seems to be behaving much nicer now. I think I need to come up with little sleeves for the spark plug wires where they pass close to metal. I have them loomed together in a few spots and routed best I could, but it's a far cry from the factory routing which seems really annoying to do with the engine in the car lol
Anyway thanks for the help everyone! Cutting out under load = possible spark leak
Anyway thanks for the help everyone! Cutting out under load = possible spark leak
Safety Car
Joined: Mar 2017
Posts: 4,204
Likes: 1,323
From: LeClaire Iowa
You can and should use dielectric grease on spark plug boots if you want. Just got to do it correctly. here is a cut and paste on how to do it correctly. Dan
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To apply dielectric grease to a spark plug boot, clean the spark plug and boot, then apply a thin layer of grease inside the boot and on the ceramic insulator, avoiding the metal terminals.
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To apply dielectric grease to a spark plug boot, clean the spark plug and boot, then apply a thin layer of grease inside the boot and on the ceramic insulator, avoiding the metal terminals.
Step-by-Step Instructions
- Preparation:
- Ensure Safety: Make sure the engine is turned off and has cooled down to avoid burns or electrical shock.
- Remove the Boot: Carefully pull the spark plug boot off the spark plug using a twisting motion. Avoid yanking the wire to prevent damage.
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- Clean the Components:
- Use a clean cloth or paper towel to wipe away any dirt, debris, or old grease from both the spark plug and the inside of the boot. This ensures a clean connection.
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- Apply Dielectric Grease:
- Amount: Squeeze a small amount (about the size of a pea) of dielectric grease onto a cotton swab or directly into the inside of the boot.
1 - Where to Apply: Apply a thin layer of grease to the inside of the spark plug boot and lightly on the ceramic insulator of the spark plug. Do not apply grease to the metal terminals or electrode, as this can interfere with electrical conduction.
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- Reattach the Boot:
- Push the boot firmly back onto the spark plug until you feel or hear a click. This ensures a snug fit and helps form a moisture-proof seal.
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- Final Check:
- After reattaching, ensure that the boot is seated securely and that there is no gap between the boot and the spark plug. This will help maintain optimal ignition performance and prevent moisture ingress.
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Benefits of Using Dielectric Grease
- Prevents Arcing: It creates a non-conductive barrier that prevents electrical arcing, which can lead to misfires and engine damage.
- Reduces Corrosion: The grease helps repel moisture and contaminants, protecting the electrical connections from corrosion and extending the lifespan of the spark plug and boot.
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By following these steps, you can effectively apply dielectric grease to your spark plug boots, ensuring better performance and reliability of your ignition system.
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Thread Starter
Instructor
Joined: Jun 2024
Posts: 126
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Replaced the spark plugs with brand new ones. Still has a minor stutter under heavy acceleration but seems to be doing better in every other scenario. At this point I wonder if it's something to do with the leaking intake manifold gasket ingesting oil/coolant that's causing the skip. I hope it's nothing drive line related but I haven't ruled that out.
Thread Starter
Instructor
Joined: Jun 2024
Posts: 126
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Looking at plug #1 which is right next to the small puddle of coolant on top of my intake manifold I'm starting to think this might be a part of the problem. I should probably get around to changing that intake manifold gasket 🤔
Thread Starter
Instructor
Joined: Jun 2024
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I did that and it definitely alleviated the problem in that it no longer does it leaving intersections but it still does it under heavy acceleration. What I found yesterday makes me think it's ingesting coolant in one of the cylinders under heavy load. Everything in the ignition system is new at this point and it still does this.
