| Page 22 - Index - Page 24 |
| Three Cylinder Engines Using a Combination Switch Box and Ignition Coil (CDM Modules) (Continued)
|
No fire or Intermittent on One or More Cylinders:
- If the cylinders are only acting up above an idle, connect a inductive Tachometer to all cylinders and try to isolate the problem cylinders.
- Check the trigger resistance and DVA output as given below:
|
| |
Wire |
Read To |
Resistance |
DVA |
|
| |
Purple wire
White wire
Brown wire |
Engine GND
Engine GND
Engine GND |
Open
Open
Open |
3V or more
3V or more
3V or more |
|
- NOTE: These triggers have the bias circuitry built into them, therefore you cannot measure the resistance like you could the older engines. In addition, there are four triggering coils used.
- If # 1 is not firing, disconnect #2 CDM module and see if the #1 module starts firing. If it does, the module you just unplugged is bad. If it does not, disconnect #3 CDM module and see if the #1 module starts firing. If it does, the module you just unplugged is bad.
- If # 2 or #3 are not firing, swap locations with #1 and see if the problem moves. If it does, the module is bad. A continued no fire on the same cylinder indicates a bad trigger.
|
High speed miss:
- Connect an inductive Tachometer to all cylinders and try to isolate the problem. A high variance in RPM on one cylinder indicates a problem usually in the trigger or CDM module.
- Perform a high-speed shutdown and read the spark plugs. Check for water. A crack in the block can cause a high speed miss when the water pressure gets high, but a normal shutdown will mask the problem.
- Remove the flywheel and check the triggering and charge coil flywheel magnets for cracks or broken magnets.
|
Four Cylinder Engines 1968
Engines with Ignition Driver Distributors
WARNING!! DO NOT CONNECT 12VDC TO THE IGNITION MODULE AS DC VOLTAGE WILL
BURN OUT THE SWITCH BOX AND IGNITION DRIVER.
|
No Fire At All:
- Disconnect the orange kill wire AT THE PACK and retest. If the engine’s ignition fires now, the kill circuit has a fault-possibly the keyswitch, harness or Tilt sensor.
- Check the Ignition Driver resistance and DVA output:
|
| |
Wire |
Read To |
Resistance |
DVA |
|
| |
Red
Blue
Green |
White wire
White wire,
Engine GND |
400
10
N/A |
180V or more
20v or more
150v or more |
|
- Check the cranking RPM. A cranking speed of less than 250-RPM will not allow the system to fire properly.
|
No fire or Intermittent on One or More Cylinders:
- If only one or two cylinders are not firing on this system, the problem is going to be either in the distributor cap or spark-plug wires.
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| Page 22 - Index - Page 24 |
