1953-1960 Classic Car Engines Troubleshooting Guide: Engine Misfires At Low or Idle Speeds
Things to Look For:
- Faulty spark plugs.
- Spark plugs gaps too narrow.
- Dirty or corroded secondary circuit connections or faulty ignition cables.
- Cracked or faulty distributor cap. Radial contacts in cap burned or worn.
- Dirty air cleaner.
- Leaky valves.
- Ignition point gap too narrow.
- Faulty carburetion due to: (a) float level too high or too low; (b) float valve leaking; (c) incorrect or loose jets; (d) restricted or partially clogged idle air passage or jet; (e) air leak occurring between upper and lower carburetor body; (f) air leak occurring around carburetor throttle shaft.
- Air leaks in intake manifold or carburetor resulting from: (a) loose manifold connections or leaks occurring in vacuum lines; (b) loose manifold nuts or capscrews; (c) broken or damaged intake manifold or carburetor gaskets; (d) cracked manifold; (e) warped or damaged manifold contacting surface.
- Slight leaks occurring at fuel pump check valves.
- Air leak occurring around intake valve stem because of excessive valve stem-to-guide clearance.
The Complete Guide to Troubleshooting 1953-1960 Era American Classic Car Engines