Testing dizzy hall sensor

I cannot get my car to start after putting in my new motor. I have literally tried every tooth on the distributor at TDC and, 10, 20 and 30 degrees off and the car will not start (I am getting fuel and spark). The only thing I can really narrow it down to is the hall sensor on the late model distributor (the whole ignition/lh 2.2 system is from a 88 740 using a late block mounted dizzy). The reason I suspect it is because when I pulled the motor I sort of torqued the connection a bit and the wires got pulled out somewhat. What is the proper way to test the hall sensor?

Also, if it ends up being bad is there a certain brand you recommend or stay away from? The difference between the bosch and aftermarket ones is quite significant.

Just to make sure yours is the left one in the picture, if so: Testing Hall Sensor. Failure Modes. The Hall Sensor distributor can fail through broken wiring insulation, a broken wiring connector at the side (this embrittles over time due to engine heat), or a failed Hall Sensor.

Quick Hall sensor test: [Note from Dave] the tachometer needle does jump slighty as you crank engine over if the Hall sensor is working, but the needle lays dead if the sensor is not working.

Full Hall Sensor Test: Undo the distributor connector. When the ignition is ON the Voltage between positive terminal (red lead -Nr. 3) and ground should be approx. 11V. Voltage between (blue lead - Nr.2; middle one) and ground should be 5V although if you put it on a scope you would see the sharp rise and fall from 12v to ground as the distributor rotates. Pulse frequency varies as rpm is increased. . Resistance between (black lead - Nr. 1) and ground should be close to zero Ohms. Undo connector from the control unit (above the brake pedal) and remove the sealing washers (plastic inserts on the side of the connector). Replace connector without cover or sealing washers.

- Disconnect the/red and blue leads from ignition coil. - Measure voltage between terminal 24 at rear of control unit connector (blue lead) and ground. NOTE: Connector must be attached to control unit. Switch on ignition. Turn crankshaft by hand. Voltage should indicate OVER 1.8V each time a vane passes Hall generator. Instrument should read approx."0" (0 - 0.7V) each time an opening passes Hall generator. The correct voltage is less than 0.7V or more than 1.8V.

If your hall sensor is bad, I have a new Bosch reman 2.2 distributor w/new sensor in it I wont be needing anymore.

Part # 0237 520004

This is my distributor.

Seems like my multimeter reads resistance intermittent, which it jumping a lot. I am thinking that the sensor is screwed. The dizzy is kind of beat up anyway, probably time for a reman.

If you're getting consistent spark, your distributor isn't bad. Double check the timing and firing order.

face_the_heat said:

Just to make sure yours is the left one in the picture, if so: Testing Hall Sensor. Failure Modes. The Hall Sensor distributor can fail through broken wiring insulation, a broken wiring connector at the side (this embrittles over time due to engine heat), or a failed Hall Sensor.

Quick Hall sensor test: [Note from Dave] the tachometer needle does jump slighty as you crank engine over if the Hall sensor is working, but the needle lays dead if the sensor is not working.

Full Hall Sensor Test: Undo the distributor connector. When the ignition is ON the Voltage between positive terminal (red lead -Nr. 3) and ground should be approx. 11V. Voltage between (blue lead - Nr.2; middle one) and ground should be 5V although if you put it on a scope you would see the sharp rise and fall from 12v to ground as the distributor rotates. Pulse frequency varies as rpm is increased. . Resistance between (black lead - Nr. 1) and ground should be close to zero Ohms. Undo connector from the control unit (above the brake pedal) and remove the sealing washers (plastic inserts on the side of the connector). Replace connector without cover or sealing washers.

- Disconnect the/red and blue leads from ignition coil. - Measure voltage between terminal 24 at rear of control unit connector (blue lead) and ground. NOTE: Connector must be attached to control unit. Switch on ignition. Turn crankshaft by hand. Voltage should indicate OVER 1.8V each time a vane passes Hall generator. Instrument should read approx."0" (0 - 0.7V) each time an opening passes Hall generator. The correct voltage is less than 0.7V or more than 1.8V.

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Having a similar issue, im getting around 15v when I should be getting 11v you say. What's wrong? Could it have to do with the plug in battery charger I'm using?