[T3] Lean Cruise

[Jim Adney]

On 8 Mar 2013 at 21:40, Max Welton wrote:

> The problem I had was that in my normal day, I traverse a 1500'
> altitude change. The fuel law didn't know that the ambient pressure
> was changing and for a while it made nailing down the VE-table a real moving target.
> 
> Adding the second MAP sensor is one of the standard megasquirt modifications. It allows the ECU to read ambient pressure 
> continuously. Problem solved.

The MAP sensor tells MS what the air pressure is in the IAD. That and 
the RPM are only things that control how much air gets into the 
cylinders. Ambient pressure may have some slight effect on the vacuum 
advance and the air drag on the car, but it doesn't have any effect 
on what's happening in the cylinders. That's one of the big 
advantages of the D-jet system: It's independent of altitude.

I don't see that there was a problem to be solved.

-- 
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Jim Adney, jadney at vwtype3.org
Madison, Wisconsin, USA
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