Hi guys,
My '93 Lancer GSR doesn't fire on two of the cylinders (2,3) and also won't start. I ruled out the following:
- Fuel pump failure
- Coil Pack failure (bought a replacement one and same problem)
Checked the resistance on the coils and this was in range (12kOhm), so no shorted turns or open circuit. I investigated further and found that the power transistor on the ignitor/coil pack module (J722T) was not triggering on one of the coil packs (but is triggering on the other), even though there is power to the module.
Trigger signal comes from ECU. Opened this up to check for any exploded capacitors that may have shorted bits of the circuit board of the ECU together. It looked as clean as when it left the factory.
Then I looked at what inputs go to the ECU for timing/ignition and examined the Crank Angle Sensor (CAS). It's mounted on the end of the inlet cam, and the module (J822) also contains a TDC sensor and transistor circuit. I checked that there was power to it (rigged up some clip leads and wires to make a test point between connector and plug), which there was. Also 5V signal coming from both TDC and CAS leads of the ECU.
I cranked the engine over (using the starter motor) and checked that the 5V signal was interrupted on both the TDC and CAS sensors, as it should be when the sensor plate passes by the magnetic pickups. Results TDC constant 4.9V, CAS varied voltage between 0, 5V
Conclusion: faulty TDC sensor.
Question: Can anyone sell me another CAS/TDC sensor module (Don't know how to make a post in the classifieds so apologies if in wrong thread etc..)
Hope this is otherwise useful to someone and sorry if it duds an auto-elec/mechanic/lube mobile out of $500 to fix this type of problem
My '93 Lancer GSR doesn't fire on two of the cylinders (2,3) and also won't start. I ruled out the following:
- Fuel pump failure
- Coil Pack failure (bought a replacement one and same problem)
Checked the resistance on the coils and this was in range (12kOhm), so no shorted turns or open circuit. I investigated further and found that the power transistor on the ignitor/coil pack module (J722T) was not triggering on one of the coil packs (but is triggering on the other), even though there is power to the module.
Trigger signal comes from ECU. Opened this up to check for any exploded capacitors that may have shorted bits of the circuit board of the ECU together. It looked as clean as when it left the factory.
Then I looked at what inputs go to the ECU for timing/ignition and examined the Crank Angle Sensor (CAS). It's mounted on the end of the inlet cam, and the module (J822) also contains a TDC sensor and transistor circuit. I checked that there was power to it (rigged up some clip leads and wires to make a test point between connector and plug), which there was. Also 5V signal coming from both TDC and CAS leads of the ECU.
I cranked the engine over (using the starter motor) and checked that the 5V signal was interrupted on both the TDC and CAS sensors, as it should be when the sensor plate passes by the magnetic pickups. Results TDC constant 4.9V, CAS varied voltage between 0, 5V
Conclusion: faulty TDC sensor.
Question: Can anyone sell me another CAS/TDC sensor module (Don't know how to make a post in the classifieds so apologies if in wrong thread etc..)
Hope this is otherwise useful to someone and sorry if it duds an auto-elec/mechanic/lube mobile out of $500 to fix this type of problem
