Misfires at idle
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Joined: Aug 2004
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Thought I'd take some time to answer your FIC questions Dan.
The FIC retards the timing by retarding the cam and crank signal. Generally you can't just retard one and not the other because the factory computer expects the cam signal to arrive in a specific time window or it will decide that the cam or crank sensor is defective and throw a CEL.
It's not that hard to advance the timing using the same sort of scheme but the FIC has no idea what the trigger pattern is on the ralliart. It knows how many pulses per revolution and it knows when to fire each injector based on when the factory computer tries to fire the injector. It needs the trigger signals because on rundown the factory computer stops firing the injectors and the FIC still needs to know what RPM the engine is turning at.
So the first para lets you in on how they control the injectors. They have 4 sense wires that put "load" on the OEM injector drivers so the ECU won't detect a bad fuel injector - not sure if the ralliart does but some other brands detect that. It then monitors the pulsewidth that the factory computer "drives" the injector and applies your adjustments to it's own set of injector drivers which are really driving the fuel injectors.
The FIC is also able to commit sensor trickery. It can adjust the MAF signal and has 2 analog input/outputs as well as a circuit to drive the O2 channels. So you can use it to clamp the MAP so the factory ECU sees no boost and it can adjust the MAF signal so it doesn't see too much air. That feature does not work particularily well on the ralliart which is probably related to their ADC impedance.
I have tried to run the system both ways independantly and in concert hence my indepth knowledge of what its shortcomings are on the ralliart.
-Michael
The FIC retards the timing by retarding the cam and crank signal. Generally you can't just retard one and not the other because the factory computer expects the cam signal to arrive in a specific time window or it will decide that the cam or crank sensor is defective and throw a CEL.
It's not that hard to advance the timing using the same sort of scheme but the FIC has no idea what the trigger pattern is on the ralliart. It knows how many pulses per revolution and it knows when to fire each injector based on when the factory computer tries to fire the injector. It needs the trigger signals because on rundown the factory computer stops firing the injectors and the FIC still needs to know what RPM the engine is turning at.
So the first para lets you in on how they control the injectors. They have 4 sense wires that put "load" on the OEM injector drivers so the ECU won't detect a bad fuel injector - not sure if the ralliart does but some other brands detect that. It then monitors the pulsewidth that the factory computer "drives" the injector and applies your adjustments to it's own set of injector drivers which are really driving the fuel injectors.
The FIC is also able to commit sensor trickery. It can adjust the MAF signal and has 2 analog input/outputs as well as a circuit to drive the O2 channels. So you can use it to clamp the MAP so the factory ECU sees no boost and it can adjust the MAF signal so it doesn't see too much air. That feature does not work particularily well on the ralliart which is probably related to their ADC impedance.
I have tried to run the system both ways independantly and in concert hence my indepth knowledge of what its shortcomings are on the ralliart.
-Michael
the ignition is controlled by a signal from the ECU to each individual coil pack. there is no external electrical source for the charge, the coil pack merely needs a signal to fire and produces it's own charge. the timing signal is derived from the cam and crank sensors.
there is two ways to control timing, fool the sensors or control the igniter. I believe the FIC controls the cam sensor (maybe both) and can only retard the timing. either way it would only be able to retard the timing using those signals because they are odd signals and are difficult to predict.
still confused a little though
there were between 12 and 14 before... but under what driving condition?
driving they're (this could be they were or they are, which is why I am still confused. your verb tenses are mixed in the above paragraph ) in the 14's.
when you stop, they go to 11's or 12's (too rich, I agree)... then you go on to say you couldn't fix it with the FIC... when? now or then? it wasn't a problem before (the 11's or 12's at idle I am assuming) but now it's become a problem?
fuel wise it's piggybacking the injector, but is it intercepting or emulating the injector signal? in other words, is it a fuel map or an add/subtract map? specifically did you have to start from no fuel and build the entire map or did you add a percentage of fuel in each cell you needed fuel in and all other cells were empty?
sorry about all the questions.
if the FIC won't affect AFR's like it should the ECU might be fighting it. I don't believe anyone else has tried the injector piggyback method with this ECU yet, so you would be the first and therefor likely to encounter new issues
there is two ways to control timing, fool the sensors or control the igniter. I believe the FIC controls the cam sensor (maybe both) and can only retard the timing. either way it would only be able to retard the timing using those signals because they are odd signals and are difficult to predict.
still confused a little though
there were between 12 and 14 before... but under what driving condition?
driving they're (this could be they were or they are, which is why I am still confused. your verb tenses are mixed in the above paragraph
) in the 14's.when you stop, they go to 11's or 12's (too rich, I agree)... then you go on to say you couldn't fix it with the FIC... when? now or then? it wasn't a problem before (the 11's or 12's at idle I am assuming) but now it's become a problem?
fuel wise it's piggybacking the injector, but is it intercepting or emulating the injector signal? in other words, is it a fuel map or an add/subtract map? specifically did you have to start from no fuel and build the entire map or did you add a percentage of fuel in each cell you needed fuel in and all other cells were empty?
sorry about all the questions.
if the FIC won't affect AFR's like it should the ECU might be fighting it. I don't believe anyone else has tried the injector piggyback method with this ECU yet, so you would be the first and therefor likely to encounter new issues
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