Missing out
Thread Starter
6th Gear
Joined: Apr 2005
Posts: 6
Likes: 0
Missing out
The engine is missing on 2-3 cylinders. When I put new spark plugs in (standard Autolites) the car runs like a champ. Then after a little while, it starts to miss on a cylinder, then another, and then sometimes another. The spark plugs all look fine when I check them. I have an MSD points dist. The carbeuretor is an Edelbrock 600cfm with electric choke.
I'm learning about working on Vettes/cars as I go, so go slow with me.
Pat
1971 Steel Cities Gray Coupe
I'm learning about working on Vettes/cars as I go, so go slow with me.
Pat
1971 Steel Cities Gray Coupe
Le Mans Master
Joined: Apr 1999
Posts: 6,134
Likes: 46
From: Raleigh North Carolina
Originally Posted by 71Ttops
I'm not sure. How would I check that?
Pull a plug wire off one spark plug on the engine and hook it up to one of the "bad" plugs which you previously removed.
Connect a ground to the removed plug threads. (wire/connection from the plug threads to the engine or chassis ground: Battery -)
Start the engine... the plug should fire if it's good.
Drifting
Joined: Apr 2004
Posts: 1,651
Likes: 11
From: Seattle WA
Sounds to me like you have bad wires. The reason they work when SP's are new is that the resistance to firing increases as the plug's age. Not a great deal but enough that if you have bad wires that may cause the miss. Just because they look good doesn't mean they are.
One way to test them is to run the car in the dark and look for arcing. You might be surprised what you'll see.
Another way to test is to make a really good test wire that you know is good and run it directly from the dist to the plug.
Vette's are notorious for being wire eaters, particularly if you have them routed in the OEM configuration. It's a function of all the heat from the manifolds.
One way to test them is to run the car in the dark and look for arcing. You might be surprised what you'll see.
Another way to test is to make a really good test wire that you know is good and run it directly from the dist to the plug.
Vette's are notorious for being wire eaters, particularly if you have them routed in the OEM configuration. It's a function of all the heat from the manifolds.
