Hi,
few questions about how VEMS controls the VVT solenoid.
1. is there a function to disable VVT solenoid when engine is warming? At cold oil (higher viscosity) idling is difficult because of the valve timing continuosly changing, as it would need a setup totally different from hot oil.
2. question about VEMS PID.
I noticed that I can't get all the solenoid DC, needed to get to the target VVT angle, just by using the Proportional gain, but it only arrives up to 25% DC.
And to get up to the rest of the needed DC (around 50%) I absolutely need to add some Integral.
It's a very strange PID behaviour, compared to others ecus.
3. is it ok to have the sectrig position +/-1.5° from the camshaft target value? Wasn't able to do any better..
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Hi,
issue #1 solved by lowering target angle.
But now i'm fighting again a worse issue.
VVT solenoid starts to change camshaft timing when around a minimum of 40%, that is to say no angle change from 0 to 40% DC.
Problem is that it gets a pair of seconds to get from 0 to 40%, even with maximum Proportional gain, so it's like VVT disabled in shorter gears.
Would be very handy to have a minimum/maximum allowable DC even for VVT solenoid, so that PID could start working from 40% DC (in my case), or even a Normal Position DC table to help PID to get faster to the target.
Camshaft Angle control/Reference position is already at 50%, but changing it was of no help (changed nothing).
Is there any other way to solve that?
Thanks