Questions and Answers

Plymouth Horizon Missing And Stalling Q. I drive an 1985 Plymouth Horizon with some 130,000 miles on it. I am once again experiencing problems with the engine missing and stalling. This time it is occurring only when I turn the A/C on which is unusual for this recurrent problem.

I have recently moved so my previous, WONDERFUL mechanic is no longer available to me. He took it as a challenge to keep my li'l auto moving along. Periodically, he spoke of the ignition coil or the pickup coil when he was telling me about repairs he had made. Are these parts one and the same? Or are they different? If so, what is the pickup coil and where is it located and within what system, electrical, ignition, whatever? I know about the ignition coil.

And my final question: what do you think my problem is? Why is the engine "coughing" and appearing to momentarily stall?

Thank you in advance for offering up your expertise.

A. Four cylinder engines have the pickup coil located in the distributor. This coil supplies the basic timing signal to the computer. The computer also uses this signal to determine engine RPM, location of piston during compression stroke and when engine is in cranking mode.

Hall Effect Pick Up Coil

The ignition coil is triggered by the computer based on the signal supplied by the Hall Effect Pick Up Coil. Both the Hall Effect Pick Up Coil and the ignition coil are part of the ignition system.

That particular engine had problems with the Hall Effect Pick Up Coils going bad, so that would be the first thing I would suspect.

Another possibility is the carburetor base gasket. These carburetors were mounted on a rubber insulator that, quite often, cracked. Thus creating a vacuum leak which would also cause the symptoms you describe.