MicroSquirt.com read only forum (Jan.15,2018)

Hello

I have microsquirt v3 and code 3.78. I have set alpha n blending limit to 9000 rpm, so I suppose it should be pure Alpha N.

What is difference between these two Blend SD/Alpha N control algorithms (PW=--VE(tps,rpm)) and (PW=--f(tps)xVE(tps,rpm)) ?

I have chosen the first one.

Problem is following:

With engine off, the "dot" on ve-table follows TPS at "kpa" axis. With engine running, the dot is continuously at zero kpa. In ALPHA N map table the value changes.

What could cause this?

I recorded a video of the situation: http://youtu.be/23_UaIXskwoh

Thanks for advise.

As best I remember, the reason for the reason for the 2nd blend algorithm is to make the SD and alphaN algorithms look the same. In SD, the pulsewidth is calculated from MAP x VE(MAP, Rpm). When you go WOT, Map jumps to near 100 kPa and VE is close to 100. The same idea translated to alphaN would be to use Tps x VE(Tps, Rpm), where Tps jumps to 100% when the throttle is WOT. This allows VE to be in the same range for both SD and alphaN, so makes it easier to blend or switch between the two modes. There is also a physical reason for this. With SD, Map is needed to get the mass air entering the cylinder. The analogy in alphaN is that tps represents the throttle area and so controls the air going into the cylinder. Then VE in both cases can be what it is meant to be - primarily a measure of how much air can be stuffed into the cylinder, so it is primarily a function of cam timing and the resulting residual exh gas that is trapped in the cylinder, preventing more fresh air from entering.

OK, thanks for info. I still need help to get the VE table to follow throttle position according to AlphaN MAP -table. I uploaded the code 3.78 again and loaded the old settings without change. Attached is current configuration file.

I noticed that even map reading does not refresh after starting engine. I did not pay attention to it because engine is single cylinder. But even with external vacuum source on the MAP hose, the reading freezes when starting engine, and starts updating only when engine is shut down from ignition kill switch. Maybe related to same problem / error, but what could it be?

Today I loaded the code "Monitor_v2.905.abs.s19" to the unit and everything I need is working.

Maybe problem was related to MAP sampling settings, but I could not get it working with any values.

Vili wrote:Today I loaded the code "Monitor_v2.905.abs.s19" to the unit and everything I need is working.

Maybe problem was related to MAP sampling settings, but I could not get it working with any values.

That is quite possible since the code samples on time when there is no engine sync, but samples on crank angle when there is sync. Since you are not running in Dual Spark mode, there isn't much advantage to using the newer code.