Ignition Timing of a FC
03-10-2008, 03:29 PM
#1
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Thread Starter
Join Date: Jun 2006
Location: Germany
Posts: 70
Hey guys,
i have a special stupid question about Ignition Timing of the FC.
Ok we have a crank angle sensor.. what exactly does it? Our Ignition Timing is controlled by the ECU via Ignition MAP. So what is the job of the Crank Angle sensor, and how does it influence the OVERALL timing if turn it?
I have some thought how it works and stuff, but i am just not sure about it..
Is this correct?:
Adjusting the crank angle sensor to the FSM standard: Leading 5° Trailing 20° will hold my overall ECU-Timing to the put in data, for example if there is a cell with 20°, then it are "real" 20°.
so, if i adjust the crank angle sensor by turning it "forward" and the indicator shows me: leading 0° Trailing 15°.. does it then influence my whole ignition map by subtracting 5°? Lets say i have a cell with 20° BTDC, so do i get "real" 15° ?
please tell me what happens if i turn the crank angle sensor, and dont flame please
i have a special stupid question about Ignition Timing of the FC.
Ok we have a crank angle sensor.. what exactly does it? Our Ignition Timing is controlled by the ECU via Ignition MAP. So what is the job of the Crank Angle sensor, and how does it influence the OVERALL timing if turn it?
I have some thought how it works and stuff, but i am just not sure about it..
Is this correct?:
Adjusting the crank angle sensor to the FSM standard: Leading 5° Trailing 20° will hold my overall ECU-Timing to the put in data, for example if there is a cell with 20°, then it are "real" 20°.
so, if i adjust the crank angle sensor by turning it "forward" and the indicator shows me: leading 0° Trailing 15°.. does it then influence my whole ignition map by subtracting 5°? Lets say i have a cell with 20° BTDC, so do i get "real" 15° ?
please tell me what happens if i turn the crank angle sensor, and dont flame please
03-10-2008, 07:35 PM
#2
Senior Member
Join Date: May 2002
Location: California
Posts: 22,465
the way it works is thus;
the CAS has 2 sensors in it, the "NE" and the "G" signal. i forget which one is which.
one signal triggers once each crank revolution, the other gives a signal every 30 or so degrees.
the ecu interprets the 2 signals as rpm, AND engine engine position. in order to do timing, and sequential fuel injection, the ecu needs to know WHERE the engine is.
so the ecu sees this, and it knows when it see's the 'home' trigger that the engine is at a certain point, and the timing map comes from that.
so its home trigger + rpm + load = timing output
so when you advance the tmining with the CAS it advances the whole timing map, because instead of the tigger happening at 65degrees before top dead center (i dont know an actual value), its now happening at a smaller number, like 60.
the CAS has 2 sensors in it, the "NE" and the "G" signal. i forget which one is which.
one signal triggers once each crank revolution, the other gives a signal every 30 or so degrees.
the ecu interprets the 2 signals as rpm, AND engine engine position. in order to do timing, and sequential fuel injection, the ecu needs to know WHERE the engine is.
so the ecu sees this, and it knows when it see's the 'home' trigger that the engine is at a certain point, and the timing map comes from that.
so its home trigger + rpm + load = timing output
so when you advance the tmining with the CAS it advances the whole timing map, because instead of the tigger happening at 65degrees before top dead center (i dont know an actual value), its now happening at a smaller number, like 60.
12-07-2009, 02:08 AM
#3
Member
Join Date: Sep 2006
Location: Sylmar
Posts: 31
the way it works is thus;
the CAS has 2 sensors in it, the "NE" and the "G" signal. i forget which one is which.
one signal triggers once each crank revolution, the other gives a signal every 30 or so degrees.
the ecu interprets the 2 signals as rpm, AND engine engine position. in order to do timing, and sequential fuel injection, the ecu needs to know WHERE the engine is.
so the ecu sees this, and it knows when it see's the 'home' trigger that the engine is at a certain point, and the timing map comes from that.
so its home trigger + rpm + load = timing output
so when you advance the tmining with the CAS it advances the whole timing map, because instead of the tigger happening at 65degrees before top dead center (i dont know an actual value), its now happening at a smaller number, like 60.
the CAS has 2 sensors in it, the "NE" and the "G" signal. i forget which one is which.
one signal triggers once each crank revolution, the other gives a signal every 30 or so degrees.
the ecu interprets the 2 signals as rpm, AND engine engine position. in order to do timing, and sequential fuel injection, the ecu needs to know WHERE the engine is.
so the ecu sees this, and it knows when it see's the 'home' trigger that the engine is at a certain point, and the timing map comes from that.
so its home trigger + rpm + load = timing output
so when you advance the tmining with the CAS it advances the whole timing map, because instead of the tigger happening at 65degrees before top dead center (i dont know an actual value), its now happening at a smaller number, like 60.
12-07-2009, 02:24 AM
#4
Member
Join Date: Sep 2006
Location: Sylmar
Posts: 31
sorry for the aimless quote, i didnt get to type anything 'cause my other pc sucks and went ahead and did it's own will.
ANYWAY, i was wondering if the CAS is powered by any one of the four wires connected to it. im sort of in a debate with a buddy and he says the CAS should be powered by some means in order to perform its duty.
im not getting spark and i've already ohm'd out my CAS and coil ignitors. they're all in good working order :/ im afraid to blame my ecu
ANYWAY, i was wondering if the CAS is powered by any one of the four wires connected to it. im sort of in a debate with a buddy and he says the CAS should be powered by some means in order to perform its duty.
im not getting spark and i've already ohm'd out my CAS and coil ignitors. they're all in good working order :/ im afraid to blame my ecu
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