Testing the ignition control module is a little trickier. When the module is exposed to a specific heat range—which can vary—it tends to fail. Therefore, the test may not be accurate.

The HEI distributor is an inductive-discharge-style ignition, but with the points replaced by a solid-state switching device called an electronic ignition-control module.

Instead, if possible, you’ll want to test the ignition module to verify it’s the issue. The process of testing your module is heavily reliant on the model you have to work with.

CD ignition use a separate coil and ignition box along with the distributor, and the system makes it easy to fire a really hot spark all the way through the rpm range.

Classic Delco distributors seem to cover the gamut of types, ranging from single-point to dual-point in aluminum and cast iron. We're about to tackle a cast-iron, tach-drive distributor.

[Dan] wanted to learn a bit about solid state ignition in engines; to get started he needed a test subject, so he decided he would upgrade his old 12 horsepower lawnmower. Originally the lawnmower … ...