Author Topic: AlphaN problem with 1.1.8x and 1.1.9x and vemstune bug?  (Read 21581 times)

Offline Sprocket

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Re: AlphaN problem with 1.1.8x and 1.1.9x and vemstune bug?
« Reply #15 on: August 11, 2011, 12:58:43 am »
Rob, there is an Alpha-N IAC compensation. I initially got confused in a similar vein since I had it enabled without knowing and without any IAC. The IAC integral was increasing trying to raise the idle and moving the active point up the map which started to richen it right up. Took a while to reallise that the active VE point was moving on its own because of this even though there was no throttle input. What drew me to the IAC settings with a little help from GintsK pointing out the config point (called IAC to Load in 1.1.44) was the fact that the active VE point moved up and down the VE map with key on, the same as the stepper motor closes then opens on key on.

If IAC type is configured for stepper or PWM and the IAC refference table that is associated with it, is configured with anything other than zeros, the active VE point will move in direct relation to the IAC position, as a factor of the 'Alpha N IAC compensation' configured value. Change this value and it either increases or decreases the amount the active VE point moves up the table relative to the IAC refference table. This allows extra fuel to be added with the operation of the IACV as though it was the throttles moving rather than an independant valve.

If the 'Alpha N IAC Compensation' value is set to zero, it will dissable this feature and the active VE point on the VE table should now represent the actual TPS


Check the value set in 'alpha N IAC Compensation' under Starting/ Idle then Idle Control General. temporarily set it to zero and see if what you perceive to be the problem disappears, but if you have an IACV then this 'false' active VE point you seem to be experiencing is normal. It might just need tuning.

If you have ITB's and no IAC then you need to set the 'Alpha N IAC compensation' to zero and perhaps even set the IAC refference table to zeros as well. Maybe even set the IAC control type to on/off, but I'm not sure how that changes other things at this time.

Also, as has already been explained previously, the two VE maps you are looking at, while the same, are infact different. One is MAP/ RPM and the other is TPS/RPM. If you have Alpha N enabled you should ignore the MAP/RPM table. Don't let it confuse you un-necessarily.

Offline rob@vems.co.uk

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Re: AlphaN problem with 1.1.8x and 1.1.9x and vemstune bug?
« Reply #16 on: August 11, 2011, 08:09:26 am »
This was using 1.1.18 so none of that joy for me :(
Still its good to know about another feature.

Rob

Offline Ignitec

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Re: AlphaN problem with 1.1.8x and 1.1.9x and vemstune bug?
« Reply #17 on: August 11, 2011, 05:41:59 pm »
On 1.1.84 worked very nice, but until I changed Alpha-N iac compensation (was 198 by default - very bad), it was like famous "black smoke racing" in idle whatever i do... :)
If you have everything under control, you\\\'re not fast enough!

Offline z0tya

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Re: AlphaN problem with 1.1.8x and 1.1.9x and vemstune bug?
« Reply #18 on: August 15, 2011, 07:55:18 am »
Doesn't your problem comes from Alpha-N IAC compensation? IMHO it is designed to add some IAC dependant VE value.

Gints

You're right!!! Thanks!

Zotya