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Autronic trigger and Ignition Setup
Autronic Ignition Setup
One of the most important things in ECU setups is the crankshaft and camshaft trigger setup. If setup is not correct, ECU’s ignition and injection times might not be accurate.
For 4-cyl engine Autronic recommends 4 trigger events / 720 degrees, about 60 degrees before TDC.
How to setup the triggers:
- Turn the engine so that Cyl1 is 60 degrees before TDC (BTDC)
- Position the trigger disc so that the tooth is in the center of the crank sensor
- Now turn the engine so that the crank sensor is between the tooth and the next tooth. 10 degrees after the previous one and more than 10 degrees before the next one.
- Now adjust the cam sensor so that the camshaft tooth is in the center of the sensor.
HINT: SM4 firmware 1.09 and later supports a Cyl/Sync/HIS scope feature which makes trigger troubleshooting very easy.
Next is the Ignition Setup parameter setup in ECUCAL M-1, Ignition Setup screen:
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1. Ignition O/P’s: Since my car is equipped with individual coil packs, I need to select 4 O/P 4Cyl MC, 4 Cylinders, MultiCoil. If you press Enter at Parameter 1, Ignition O/P and select Advanced you can see the ignition timing events. 2. Ign trigger edge: This is set to –ve edge (DWELL) and this varies depending what coils you have. This is what I use with Honda S2000 coils 3. Dwell/pulse times: User defined, since I’m using my own Dwell table 4. Ign delay time: This is how long it takes for the coil to produce the spark. I measured this using an oscilloscope and is the time from the trigger event till the spark was given. 5. Ign retard clamp: Max amount of advance allowed 6. Gin advance clamp: Max amount of retard allowed |
Next select M-1, I/P Cylinder & sync:
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1. Trig decoder: Cylinder pulses 2. Trigger events/cycle: This is the amount of triggers / 720 engine degrees. 2 crank triggers = 4, 3 crank triggers = 6 etc… 3. Cylinder I/P lead: 69 degrees in my case. Very important setting and affects directly to ignition accuracy. See Tuning I/P Lead 4. Digital angle filter: The Digital Angle filter relates to the predictive ignition timing algorithm which is most noticable during engine acceleration and deceleration. When set to Fast it is necessary for the cylinder pulses to have highly accurate spacing otherwise any errors in the cylinder pulse spacing can be amplified. When set to Slow the algorothim determines the engine position over more cylinder pulses so any pulse spacing errors are filtered out. 5. Cylinder sensor: Choices are reluctor or Hall type. When using reluctor type, make sure wave rises and then falls when triggered. I’m using GT101 Hall sensor, so I must use Hall. 6. Cylinder trig edge: Rising in my case since signal rises when the trigger passes the sensor. NOTE: For reluctor type this has to be Falling 7. Cylinder I/P filter: Slow. If less than 10 crank pulses, use Slow. Otherwise Fast. 8. Sync Sensor: This refers to Cam sensor and same logic as with Cylinder sensor setting is used. I use GT101 as a Cam sensor as well. 9. Sync trigger edge: Same logic as Cylinder trigger edge 10. Sync I/P signal: Must be set to Yes if Knock detection is used and also should be set to Yes when used with Multi-coil systems like in my case. NOTE: Ignition is inhibited If set to Yes and Sync signal is not received. 11. Measure freg: Disabled 12. Alternate cam2 input: Disabled since I’m using one Sync trigger 13. RPM>Sync Err Detect: 50rpm. Sync error detection is active after this RPM 14. RPM>CamPosErr detect: 500rpm. Camshaft position error detect RPM |
Engine should start after all these parameters are set correctly. Before we can call ignition setup complete, Cylinder I/P lead has to be tuned. Otherwise ignition event might not happen at the right time.
Tuning Cylinder I/P Lead:
For this you need to know when cyl 1 is at TDC. If you don’t have the timing marks, you need to create the marks. Just rotate the cylinder 1 to TDC and make sure cyl1 valves are closed and engine is at power stroke.
Next you need to modify your map so that timing table has flat 0 degree ignition advance at low and idle loads. All ignition trims must be disabled.
Connect your timing light to Cyl1 coil.
Start the engine and adjust the Cylinder I/P lead value until timing marks are aligned. Now the timing is accurate since ignition event happens at TDC, when 0 degree ignition advance is used.
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