985322 Volvo.Penta Flange screw

Ignition Transformer
Illustration 1 g00326433
Components Of The Gas Engine Ignition Group (1) High energy ignition transformer. (2) Tube. (3) Extension with a spring loaded rod. (4) Spark plug.The ignition transformer causes an increase of the primary voltage. The increased voltage is needed to send a spark (secondary electrical impulse) across the electrodes of the spark plugs. For good operation, the connections (terminals) must be clean and tight. The negative transformer terminals for each transformer are connected together and the terminals are connected to ground.Timing Control System
The Caterpillar Detonation Sensitive Timing Control (DSTC) system provides detonation protection for the engine and electronic adjustment of ignition timing with a variable timing. This ignition system consists of four basic groups.
Timing Control Module
Ignition Control
Detonation Mixing Control (DMC) System
Sensors
Illustration 2 g00494465
Timing Control SystemTiming Control Module (TCM)
The TCM determines the ignition timing. The TCM communicates the ignition timing with the Ignition Control. The TCM provides the system diagnostics.Engine timing, controlled by the TCM, is based upon the desired timing signal received from the ECM. The desired timing signal from the ECM varies depending on engine speed, engine load and engine detonation.The ignition timing is controlled by three signals that are sent from the TCM to the Ignition Control. The Ignition Control sends a signal that indicates that the plug is firing to the TCM. The TCM uses this signal to calculate actual engine timing.Caterpillar Ignition System (CIS)
The Caterpillar Ignition System has been designed for gas engine applications in conjunction with the TCM. The ignition system is intended to replace both the magneto and the magneto interface box. The existing ignition coils and the wire connection to the TCM are still utilized. The addition of a Cam Position Sensor and a trigger magnet are required as a cycle trigger. The sensor and the magnet are installed on the cam at the oil mist drive location at the front right hand side of the engine. New features include advanced spark control, spark diagnostics, self-diagnostics, diagnostics, sensor diagnostics and serial port communications. The system consists of two main parts: The engine mounted ignition control module and the remote mounted optional user interface display module. The system requires 24 VDC at 5 amp nominal for typical application.Note: The ignition system must be configured prior to use on an engine. All components from the factory and parts departments are properly configured for your engine. Ensure that you have the correct part number for your application.Ignition Control ModuleThe ignition control module is equipped with a 16 position manual timing switch in the output module and a start-up retard that is adjustable via the terminal software. The maximum allowable ambient temperature exposure of the control module is 65.5°C (150°F) .The manual timing switch affects the timing that is reported to the TCM during the engine crank, or while in the "MAG CAL" mode. The ignition control module was designed to be transparent to the TCM, which fires at the fully advanced ignition timing while the engine is under 500 rpm. Therefore, in order to avoid a "MAG CAL" fault, the ignition must report the timing to the TCM in order to match the fully advanced timing by 1 degree. When the engine speed is above 500 rpm, then the electronic timing is activated. The manual timing switch has no effect on the engine timing.In order to facilitate better starting, the ignition control module is configured to permit the timing to be retarded from the full advance setting while the engine is below 500 rpm. This adjustment is a retard offset from the Reported Timing. Once the engine speed is above 500 rpm, the electronic timing is activated. The start-up retard timing adjustment setting has no effect on the engine timing.The timing reported to the TCM is calculated as follows:Reported timing=Opening of Cam Position Window-6 degrees-manual switch settingThe actual engine timing is calculated as follows:Actual timing=Reported timing-Retard adjustmentNote: The Retard Adjustment has no effect on the timing that is reported to the TCM and will not cause a "MAG CAL" fault.Note: Changing the Reported Timing changes the Actual Timing by the same amount.Cam Position Sensor And Trigger MagnetThe Cam Position Sensor senses a magnet which must be fixed at the proper angular position of the cam gear. The leading edge of the Cam Position Sensor signal represents the reset signal of the ignition in manual/start-up timing mode. In the electronic timing mode, the Cam Position signal is used to select the reset pulse from the TCM that occurs during the compression stroke (the TCM generates reset pulses during both the compression stroke and the exhaust stroke). The air gap between the Cam Position Sensor and the trigger magnet must not exceed 1.0 mm (.04 inch) .Optional Ignition Control Display ModuleThe optional ignition control display module has an alphanumeric 16 character X 2 line back lighted LCD display. The display shows the operating status, the engine rpm, the secondary spark energy levels, and if the system is in single or double-strike mode.Mount the display at a convenient viewing height. Mount the display within 15 m (50 ft) of the engine mounted ignition control module. The display can be mounted inside a control panel. The display can be mounted on a suitable flat surface that is preferable off the engine. The display should be mounted in order to minimize exposure to vibration.Timing Control Sensors
The TCM uses two sensor signals for the ignition timing control. The TCM uses the detonation sensors for detonation protection. The Crank Angle Sensor (CAS) and the Speed Sensor (TCMPU) provide top center (TC) and rotational position needed to control timing. The detonation sensors provide an electrical signal of the engine's mechanical vibrations that are used in order to calculate the detonation levels.Crank Angle Sensor (CAS)This passive magnetic speed sensor indicates the crankshaft angle to the TCM. The crank angle sensor provides the TC signal used to control timing and calculate actual timing. The signal is generated when the TC hole (for the No. 1 piston) in the flywheel face