1953-1960 Classic Car Engines Troubleshooting Guide: Engine Misfires At High Speeds
Things to Look For:
- Hot spark plugs. Change to colder type but note that a hot plug may be due to loose installation or lack of a plug gasket (if gasket is called for).
- Ignition point gap much too wide.
- Breaker arm binding or sticking.
- Breaker arm spring weak.
- Sticking engine valves.
- Valve springs too weak to close valves promptly.
- Valve springs broken.
- Valve springs shimmy.
- Intermittent delivery of fuel to carburetor so that momentarily the mixture is too weak for combustion.
- Mild vapor lock.
- Weak spark.
- Exhaust manifold clogged with carbon.
- Exhaust manifold, muffler or tail pipe restricted.
- Improper ignition timing.
- Centrifugal advance not functioning properly.
- Manifold heater valve held closed.
- Dirty carburetor air cleaner.
- Choke valve not completely open.
- Carburetor throttle lever loose on shaft.
- Improper fuel pump operation.
- Incorrect valve timing.
The Complete Guide to Troubleshooting 1953-1960 Era American Classic Car Engines