Idle Timing

[04blusrt_4]

I am noticing on my car and now on another users car that my tune file is causing a severe fluctuation in timing, that is causing some misfires.

At idle, the base timing is 11* and the spark_adjust on my scan gauge jumps from .5* to -5-8*, so that my total timing jumps from 11 down to 4 or 5 and back up to 11. I happens VERY fast, in a matter of a few tenths of a second.

What is the spark modifier table I need to adjust to make this stop happening?

[04blusrt_4]

Bump TTT

[SRT-What?]

I noticed the same thing the other day, but I never had any misfire at idle or while taking off a light.

I saw that while the car was heating up I would have some spark adjustment under regular driving but these adjustments would disapear when the engine would get to operating temperature. (Almost stock S2 tune with injectors, stock thermostat )

But I would still have some spark adjustments at idle.

I can try to confirm on my way back from work.

[SRT-What?]

Yeah, I do get some minor spark adjustments at idle. 95% of the time it is in between -0.5 and -1.0. I do see -5, -8 out of nowhere while waiting, but I don't hear or feel any misfire/hesitation.

I don't know why or how, but that'S what I see.

[JANNETTYRACING]

Quote: Originally Posted by 04blusrt_4

I am noticing on my car and now on another users car that my tune file is causing a severe fluctuation in timing, that is causing some misfires.

At idle, the base timing is 11* and the spark_adjust on my scan gauge jumps from .5* to -5-8*, so that my total timing jumps from 11 down to 4 or 5 and back up to 11. I happens VERY fast, in a matter of a few tenths of a second.

What is the spark modifier table I need to adjust to make this stop happening?

You may have to close your throttle body some so the spark offset for Idle is in the Postive rather than the negative.

All it is, is trying to control Idle through spark adjustment, if you mess with the table it could Idle surge.

Been there done that.

Ted.