High End Miss
Thread Starter
Racer
Joined: Feb 2010
Posts: 261
Likes: 0
From: St. Louis Missouri
High End Miss
My 68 is an all stock matching numbers car. The engine was rebuilt several years ago and has run strong. The problem is on hot days and the engine has warmed up, it will start to miss at high RPM's. I notice it while running through the gears. Previously a member suggested to replace the coil which I did and while I thought it did the trick, last week on a hot day it did it again. I also replaced the plugs. I don't drive it a lot and do use a fuel stabilizer for storage. It's a stock 327/300, four speed.
Any thoughts?
Any thoughts?
Burning Brakes
Joined: Jan 2013
Posts: 753
Likes: 111
From: Barnhart, Missouri
I had similar issues my 68 would just die while driving and it ended up being condenser. Changed point and condenser a few days later down again. Replaced with Lectric Limited Electronic Ignition Conversion problem gone.
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
Is it more of a cutting out sensation or plugs misfiring sensation? It can be very hard to tell sometimes. Keep the throttle buried and see if it completely cuts in and out or not. If it gets worse the longer you hold the throttle down I'd look to fuel.
Pump might be getting weak, sock plugging up (if one was use in 68), float level etc.
If it's misfiring then electrical. Plug gaps? wires? condenser as mentioned.
Pump might be getting weak, sock plugging up (if one was use in 68), float level etc.
If it's misfiring then electrical. Plug gaps? wires? condenser as mentioned.
Safety Car
Joined: Dec 2012
Posts: 3,815
Likes: 1,726
From: Summerville SC
A long time ago on my c2 i had a similar issue. Chaged and adjusted everything. No luck. Then I swaped out the distributor and the problem went away. It was original to the car so probably about 12 yrs old at the time. I was too young to follow up at the time (slightly bent shaft,worn gears. I really can’t say. I just it went away and never had that problem for the next 10 years as long as I owned it. 
Is my vette stock?? HAHA
Joined: Oct 2015
Posts: 20,212
Likes: 9,350
From: Im not allowed to tell you
2020 C3 of the Year Finalist - Modified
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
could be floating the points. could be a crack in the cap if its just heat related...
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Safety Car
Joined: May 2001
Posts: 4,759
Likes: 1,647
From: Fairfax Virginia
Do you have a spare coil handy? Coils are known to act up when they get hot and as they age. I would swap a coil and see if it continues when your engine and weather both get Hot. On my 1968 BB the coil sits on top of the intake manifold and gets pretty hot and this can help them break down I was told by MSD tech support. I have gone thru 2 MSD coils and the guys at MSD blame it primarily on the heat coming off of the intake. They keep telling me to stop using the round canister style and get one that is Firewall mounted to keep it cooler and less vibration.
Good Luck, I hope you solve it before it's gets too warm outside!
Good Luck, I hope you solve it before it's gets too warm outside!
Thread Starter
Racer
Joined: Feb 2010
Posts: 261
Likes: 0
From: St. Louis Missouri
Do you have a spare coil handy? Coils are known to act up when they get hot and as they age. I would swap a coil and see if it continues when your engine and weather both get Hot. On my 1968 BB the coil sits on top of the intake manifold and gets pretty hot and this can help them break down I was told by MSD tech support. I have gone thru 2 MSD coils and the guys at MSD blame it primarily on the heat coming off of the intake. They keep telling me to stop using the round canister style and get one that is Firewall mounted to keep it cooler and less vibration.
Good Luck, I hope you solve it before it's gets too warm outside!
Good Luck, I hope you solve it before it's gets too warm outside!
and will look for the Firewall mounted unit
thanks
Is my vette stock?? HAHA
Joined: Oct 2015
Posts: 20,212
Likes: 9,350
From: Im not allowed to tell you
2020 C3 of the Year Finalist - Modified
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
do a tune up first
Thread Starter
Racer
Joined: Feb 2010
Posts: 261
Likes: 0
From: St. Louis Missouri
Misssing
My 68 is an all stock matching numbers car. The engine was rebuilt several years ago and has run strong. The problem is on hot days and the engine has warmed up, it will start to miss at high RPM's. I notice it while running through the gears. Previously a member suggested to replace the coil which I did and while I thought it did the trick, last week on a hot day it did it again. I also replaced the plugs. I don't drive it a lot and do use a fuel stabilizer for storage. It's a stock 327/300, four speed.
Any thoughts?
Any thoughts?
Melting Slicks
Joined: Sep 2016
Posts: 2,230
Likes: 984
From: Wauconda IL
I had the same problem bout 4 years ago. Here's how I solved mine.
https://www.corvetteforum.com/forums...ion-coils.html
https://www.corvetteforum.com/forums...ion-coils.html