Cold acceleration enrichments

[Tcal]

I have a few questions about that Cold AE. Warm AE is quite near where it should be..
So when i start cold engine like -5degrees CLT, engine doesn´t rev as it should when under load,
i think that it´s just configured badly..

I have now
Acceleration duration     0.3
Acc cold multip. factor   15   
Cold acc added amount  0.8

Is there a good "basic" setup for those cold values, where i can start to tune them for my engine??
Injectors are 470cc.

And one question more, what does that RPM scaling % mean in warmup enrichment table??

[Sprocket]

RPM scaling, is a % of the active warm up enrichment bin at highest RPM. If you set this to 75%, at say 6500rpm, the added warm up enricment is 75% of the active bin value, but at idle, it will be 100% (actual bin value) everything inbetween is scaled. Not too sure if it scales the whole value, IE 75 % of the bin value for example of 140%, or whether it reduces just the 'extra' portion of the bin value (140 - 100 therefore 40%)

Driving at higher RPM when the engine is cold, the actual amount of extra fuel requirement is less. If after tuning the warm up enrichments, the engine goes rich when cold, at higher RPM, reduce the scaling value

[Tcal]

Something like that i thought too, but wanted to make sure...

So if i have those warmups ok, i put like steady 3000 rpms and then just try to find good value that makes lambda reasonable, correct.?

[rob@vems.co.uk]

That sounds like a plan - the trouble with rule of thumb settings is that they may not be any good!  All it takes is an old fuel filter or wavering fuel pump voltages and the rule of thumb is rubbish.

[Tcal]

Yeah, i know that Rob.
I searched one old msq file and looked those cold AE values in it.
I found:
Acc cold multip factor  -40 ??

Shouldn´t this setting lower the value of AE when cold, or have i understood this wrong??

[rob@vems.co.uk]

Looking at the info in global.h file in the firmware directory:

acmult;       // Acceleration cold multiplication factor, biased at 100
tpsacold;     // Cold acceleration added amount (at -40 F degrees) [100 usec]


So setting acmult to 100 fixes the value to be the same as when warm, 110 would be 10% richer, 90 would be 10% leaner (why? - I dont know)

tpsacold adds a fixed amount of fuel and it gets scaled from -40deg to 77deg

[Tcal]

You prob. know that max value in that acmult is 155 in MT , does that start from -100 then??
Hmm, makes me wonder that if i put smaller value in tpsacold maybe then i should use larger acmult