Who has the random misfire problem?

[blageo23]

I got it! I just swaped a 6bolt in and it sucks. whats your idea?
Mike

[LightningGSX]

Originally Posted by blageo23

I got it! I just swaped a 6bolt in and it sucks. whats your idea?
Mike

Smooth out the crank angle pulses.Like average them out over say 4 pulses.The pulse edges will still be the same, so injectors and timing will trigger as its supposed too, but the ECU won't think there is RPM fluctuations anymore.I'm about 99% sure it will work.

[1ViciousGSX]

Originally Posted by LightningGSX

Smooth out the crank angle pulses.Like average them out over say 4 pulses.The pulse edges will still be the same, so injectors and timing will trigger as its supposed too, but the ECU won't think there is RPM fluctuations anymore.I'm about 99% sure it will work.

WTF?

[TalonFiero]

I have RM if I unselect the check in DSMLink.

Jim

[LightningGSX]

Originally Posted by 1ViciousGSX

WTF?

The ECU times the crank angle pulsewidths for RM checking.If the times change drastically, from pulse to pulse, the misfire code gets set.The injection and ignition get triggered on the falling edge of the pulse(when it goes from on to off).I'm not sure what the actual threshold is, but for example, lets say one pulse is 50 mS, and the next is 40 mS.Since normal accel/deccel can't change that quickly, the ECU interprets that as misfire.Now if you were to smooth out the pulses, like not let them change more than 2-3 mS per pulse/per 4 pulses, by extending the beginning of the pulse so the falling edge stays where its supposed to be, misfire code would be gone and nothing else would be effected.

[1ViciousGSX]

Originally Posted by LightningGSX

The ECU times the crank angle pulsewidths for RM checking.If the times change drastically, from pulse to pulse, the misfire code gets set.The injection and ignition get triggered on the falling edge of the pulse(when it goes from on to off).I'm not sure what the actual threshold is, but for example, lets say one pulse is 50 mS, and the next is 40 mS.Since normal accel/deccel can't change that quickly, the ECU interprets that as misfire.Now if you were to smooth out the pulses, like not let them change more than 2-3 mS per pulse/per 4 pulses, by extending the beginning of the pulse so the falling edge stays where its supposed to be, misfire code would be gone and nothing else would be effected.

I know what causes the code to set, I never heard of smoothing the cas signal.

[LightningGSX]

Originally Posted by 1ViciousGSX

I know what causes the code to set, I never heard of smoothing the cas signal.

Probably because no one has ever thought of it.

Scratch that anyway, I figured out a much better way of taking care of the problem, and EGR/O2/Evap codes too.Details when I know if it works.