The engine misfires intermittently (often). The two coils have been changed out with no change in misfiring. I connected a neon light to each spark plug one at a time and on No. 2 spark plug the neon light flashed twice as bright as on the other 3 spark plugs when the engine misfired. I have hesitated to replace the control module. Any suggestion would be appreciated.... Tommie Watson
Engine misfires on 1994 Oldsmobile Achieva
A professional grade scan tool often displays "number of misfire count" on individual cylinders indicating which cylinders have problems even if not yet flagged as a "PO30x" code. Jaguar and Ford can haev a dead miss due to a bad coil and not flag a code the coil can then work perfect moments later, awful to find the offending code with out a scantool. Are the spark plugs good?
Replaced the spark plug boots and the distributor cap that goes over the sparkplugs - problem solved.