I have a loud stereo.

I do have some PWM converter boards but... it idles fine so...

 

To answer my own question: I reduced the idle valve frequency from the MS3 to 50Hz and hooked it up to my own expansion board that ups the frequency to 490Hz: It idles better now and doesn't hum as loud.

 

We can probably check to see if we can add something closer to 500 Hz.

Ken

 

Now that it's been on the car for a bit what's your impression?

 

It feels smoother than the MS2, it doesn't having a random misfiring issue that the MS2 has (at least I haven't felt it for the past week), I like that it doesn't stumble when I save changes, the number of available inputs/outputs is AWESOME. It required a LOT more fuel than the MS2, around 50% in most areas (I idle at 40 in the MS2, 61 in the MS3), and I still haven't nailed down the cranking fueling - it doesn't start as nice as the MS2, but that's obviously in the tuning, and when I want to leave I'm usually in a hurry.

 

The misfire thing is funny. My MS3 missed where the MS2 didn't. Going seq. spark solved that however.

I noticed a similar thing with my fuel maps so I altered the req_fuel value instead of rescaling/retuning the fuel map.

 

Hey Dimitris,

Any chance you could scope the VVT solenoid's current draw and flyback effects?

 

Are you looking for something in particular?

 

yes in fact!

after I started using VVT, the Q3 (upper right of schematic below) transistor started to get reeeeeally hot and screwing with all my PWM outputs on the expander board.



I know you're not using that board but I'm curious if there's something about the VVT solenoid that causes problems with that circuit.

Temporary solution was a diode between VVT and +12.

Potential more universal solution is changing the 32V zener to a 22V zener.

I'm just a user so I only have a marginal grasp on cause and effect here. As I understand it, there is something about the solenoid that's forcing that transistor to dissipate a lot of power (so much that it heats up and discolors) but only with the VVT-compatible firmware.

Big ol shot of Q3:

 

I am, in fact, using the MS3X. I can easily scope the voltage, but not the current.

 

oh!

I thought you made yourself a superior board.

You could measure the voltage across the resistor R69 and infer some things about current, couldn't you?

 

Not yet, young grasshoper.

The zener is ok at 36V, it shouldn't be a problem. I will have a look with the scope if I find some time tomorrow.