10-02-2019, 03:53 PM
(10-02-2019, 02:29 PM)m in sc_imp Wrote: its not that hard to program. the cam is a direct relation to the crank. The code will just count the pulses and interpolate the position. its not a single pulse. fyi, theres NO map sensor on the grom. you can do it simply with the crank signal, engine temp, some sort of an 02 (unless you are running a static map), and tps.
Yes, you're right, no MAP on the Grom. But again, how can crank signal know which of the two revolutions of the crank in relation to the cams?
Crank and cam are not a direct 1:1 relation, as it takes two revolutions of a crank to turn the camshaft once. On each revolution of the crank, the crank pulse sensor reads the exact same signal. Yes, the ECM can be programmed to fire and fuel on alternate crank revolutions, but how does it establish which of the two revolutions?
If it is all in the ECM, then if the ECM is unplugged, the crank turned once, the ECM plugged back in, the engine will always start normally.
That suggests that all bikes would not need cam position sensor, yet some do.