Greetings,

This is my first post on this website. I am trying to learn my way around MS3. Here is my issues.

Car: 2001 Miata 1.8
Recently rebuilt ( 83.5mm supertech pistons) Manley Rods
Flowforce 640 injectors
Aem Wideband 30-0300
MS3 Pro
MkTurbo kit installed ( Wastegate currently opened for break in)

First start up with Megasquirts base map for 01-05 and Timing set (set up TPS, Wideband, Injectors pre Flowforce) also I preformed Flying Miata breaking in suggestions. Car seem to run nicely.
After oil change and some minor line tightening I went for my second ride to slowly get 25-50 miles before next oil change and anytime I pressed the clutch in and off the gas the engine would just die
(stopped or while moving). I am submitting my datalog and tune to show what happen. Any help would be amazing. Like I said I'm trying to learn my way and be able to tune. I have read many other threads on here and
know that DIYtune (tune is aggressive) but, I don't really understand what to change.

Thank you,
Matt D.
(First Post and Learning)

 

Just some quick observations;

• You're running WAY rich when you enter idle and there's a place at 800 seconds where the engine seems to be running but the AFR reading is effectively full-rich. I'd check to make sure that you wideband is wired correctly.
• You're running "Fully Sequential" fuel. If it was me, I'd turn that to batch mode (i.e. sequential off) until my tune was in better condition.
• I'd also turn off EGO for the time being. Cross that bridge when your tune is in better shape.
• I have a MS2 and when I go to "Simple" idle control, all of the other idle tweaks turn off. If it's the same with the MS3, then you can ignore the Idle Advance Settings (because they won't be active). If not, then there is a weird negative value in the "And RPM Is Below" value. It reset to zero when I looked at it, but it might still be there in your tune. Again, I'd turn off idle advance for now.
• In your Idle Control the Output Port is set to "Boost", shouldn't that be set to "Idle"?

Basically, turn off all of the automatic adjustment features, get your idle right, then turn the auto-adjustments on one by one to get to the "perfect tune". Remember, the base tune is just that - a vanilla batch of settings to get your car started but not the "best" way for your car to run. So you have to take everything in that tune with a grain of salt.

I have a MS2 and one thing I found in that environment was that it is critical to get the PWM frequency and "On" and "Off" positions of the idle valve properly set. If those are screwed up then the idle wil NEVER be right no matter how many automatic nannies are turned on. Looking at the MS3 I'm not sure how the MS2 tuning process translates to the MS3 environment. Perhaps a wiser head can help out there.

 

Very good info. How do we verify we have the right frequency for the valve? I got the high and low setting setup and currently using 313mhz.

 

Typically it produces decent open/closed duty cycles. If it doesn’t respond until ~20%, and doesn’t increase idle after ~60-80%, I figure I’m close to the correct frequency. This might be very wrong, but it seems to work for me.