A modern engine’s ECU needs to know what position the engine is in at a given moment in order to calculate correct ignition timing and in the case of sequential fuel injection setups, correct fuel injection timing.
Variable reluctance (reluctor) trigger sensors are commonly used for automotive engine control applications to accurately determine the position of a crankshaft or camshaft. The system typically consists of a trigger sensor and a toothed wheel that passes across the face of the sensor. As the tooth passes across the face of the sensor, the sensor generates a waveform which can be processed by the engine management system and used to indicate the passing of the tooth.
In many cases, an engine’s factory triggering setup can be used with aftermarket ECU’s such as the Link G4 models without any need for modifications, so in these cases a sensor such as this one will not be required.
However, an aftermarket crankshaft and/or camshaft trigger sensor and wheel may be required or preferred in the following instances:
- When an electronic ignition system has been retro-fitted to an engine with points ignition.
- When a ‘coil per plug’ or ‘wasted spark’ ignition system has been fitted to an engine that was previously using a distributor and without a suitable trigger pattern to support a distributor-less ignition system.
- When a sequential electronic fuel injection system has been fitted to an engine that was previously ‘group fire’ injection, single point injection, or carburated and without a suitable trigger pattern to support sequential injection.
- When the factory fitted triggering system or pattern is not compatible with your chosen aftermarket ECU.
- When the factory fitted triggering system has reliability or accuracy issues. This can be particularly important for engines that are modified to operate at higher RPM than originally intended. (e.g. Nissan RB engines which use the factory cam angle sensor).
This reluctor trigger sensor is available in either straight or right angle configurations and includes a 2-pin connector as shown.
This crankshaft / camshaft position sensor can be used with almost any steel trigger wheel including the following:
- In applications with sequential fuel injection or ‘coil per cylinder’ ignition, the ECU requires two triggers – A crankshaft position trigger and a ‘sync’ to determine where an engine is within a cycle, which typically comes from a camshaft position sensor or a distributor.
- Reluctor sensors work by generating an alternating voltage that has both positive and negative values that cross through the zero volt line as the teeth of the trigger wheel cross over the face of the sensor. There are two such “zero crossings” for every tooth that passes the sensor, and it is important that the correct one (polarity) is chosen to ensure accurate, stable trigger pulses. If you are unsure how to determine the correct polarity for your application, please contact us for assistance.
For wiring information and dimensions, please refer to our specification sheet.