Distributor / ECU hackers or gurus for obd1 cars
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From: Louisiana
Distributor / ECU hackers or gurus for obd1 cars
I'm trying to find out the length of the high time pin A21 (ICM) vs RPM
Here is what I logged with a oscilloscope
These are rough though
PRM - High time - frequency
600rpm - 40ms - 25hz
1100rpm -30ms - 32hz
2000rpm -15ms - 66hz
3000rpm -10ms - 100hz
3500rpm - 8ms - 118hz
The frequecy is an easy calculation RPM*2/60 , but I dont know where ecu is getting the high time from. Any help would be great! Is this a mechanical function or is it calculated inside th ecu?
Here is what I logged with a oscilloscope
These are rough though
PRM - High time - frequency
600rpm - 40ms - 25hz
1100rpm -30ms - 32hz
2000rpm -15ms - 66hz
3000rpm -10ms - 100hz
3500rpm - 8ms - 118hz
The frequecy is an easy calculation RPM*2/60 , but I dont know where ecu is getting the high time from. Any help would be great! Is this a mechanical function or is it calculated inside th ecu?
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