Crank Position Sensor Placement and Wiring

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The Crank Position Sensor is a Magneti Marelli SEN 8D.

Found one on ebay for $40 (including shipping).

Another plus for the SEN8D is that it comes with the end that mates perfectly with the EV1 connector. So another EV1 for $6.50 including pigtail.

The mounting flanges on either side of the SEN8D need to be removed and then all traces ground away so that the crank sensor can get as close as necessary to the trigger wheel. At the point the above photo was taken, I’d only removed one of the flanges (very difficult to see but it’s just below the sensor and just to the left of the lower bracket fastener. The recommended gap between the sensor and the trigger wheel is 0.3mm to 0.5mm.


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As noted earlier, when a new 36-1 trigger wheel is machined to fit the crankshaft, it must be machined so that the missing tooth portion of the trigger wheel is 90 degrees clockwise beyond (after) where the center of the crank position sensor is when the number one cylinder is at top dead center.

This photo shows that correlation.


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Close up of the crank sensor bracket. From Fast Forward for $27.50.

Performance Electronics does provide a crank position sensor but it does not fit the Fast Forward bracket which was designed to work with the Fast Forward oil pump support system. And that bracket was designed to work with the Magneti Marelli sensor. So, rather than try to have any re-machining done, I simply went with the Magneti Marelli SEN8D.

The photo above also shows the recessed portion of the crank sensor bracket. The flanges attached to either side of the SEN 8D block the sensor from snuggling down into this recess which is why they need to be ground away.


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Another crank sensor clearance issue is presented by the lower timing belt cover. A portion of the plastic shroud around the trigger wheel needs to be cut away to allow the crank position sensor a clean shot at the trigger wheel. A basic utility knife can perform the task.


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First of the lower sensor branch wiring diagrams. Crank Position Sensor.

The hookup was relatively straight forward in that I was using one of the red and black pigtailed EV1 connectors from Connectors Fast.

M32 was the signal line so it went to the red wire of the EV1 pigtail.

M26 was the ground line wire. It wired into the black wire of the pigtail.


Next Chapter: Oil Temperature Sensor Placement and Wiring