Originally Posted by stevebfl

Intermittants are the worst of problems.

You state L5. Sitting at home this doesn't mean much to me and I can't remember what is the ignition trigger on your car. I can tell you it is not on the front of the motor unless its inside the distributor.

It is either an armature like inductor inside the distributor or a crank sensor on the flywheel. The sensor on the balancer was for an engine analyser that never made it to the US. It tracks timing and isn't part of engine controls.

Looking at any of these devices with an ohm meter is not likely to find an intermittant. The signal needs to be monitored with a scope to tell whether the event is a result or the cause. RPMs logically drop when the engine stumbles or dies. I would probably use two channels and watch ignition primary on one and the engine speed signal on the other. I drive the car in snap shot mode and trigger it when the event occurs. This is adjustable but normally leaves me with a 30 second snap shot that starts 15 seconds before I trip it capturing the event for multiple reviews.

Even with proper tooling testing can be inconclusive on intermittants. This often becomes the worse source of customer irritation. They believe (I don't know why) that we should be able to test it. Well if it ain't broke it won't look broke; most times.

As much as I hate to say it, substitution is sometimes the only effective choice.