Schuyler

iTrader: (1)

1: Yeah, I'm kind of at a loss on that one at this point.

2: I'll double check it.

3: I'll turn it 3 turns clockwise and see if that fixes it.

stefanst

iTrader: (1)

The latest FW has an initial duty table for the idles valve setting. X-Axis is rpms and Y-Axis seems to be coolant temp. Values are idle valve duty. This is where your FW looks up your initial setting for the idle valve PWM when the TPS goes to 0%. Set that to the value that's usually needed at a certain temp to reach your target rpm for that temp.

Are you sure 511Hz is a good frequency for the idle valve? I believe I'm running 75Hz and that seems to work very well.

Schuyler

iTrader: (1)

This thread seems to say it's 500Hz. I'll definitely double check that idle table though.

https://www.miataturbo.net/megasquir...control-54877/


The main issue I'm still confused about though, is the fact that at different times it is taking different duty percentages to reach the same idle goal. That doesn't make sense.

Schuyler

iTrader: (1)

Turned it (R11) 3 full turns CW, made no difference. Should I turn the pot on the main board 7 turns CW as I saw you recommend in another thread?

EDIT: 7 turns CW on the main board pot made the car not crank.

EDIT EDIT: Video of the issue -

Braineack

iTrader: (62)

take a composite log a see if youre actually losing the crank or cam signal...

logs provide awesome info.

Schuyler

iTrader: (1)

Will do, give me an hour or so and I'll be back at my car. idk if it tells you much or not, but here is a screenshot I'd posted of the issue in my build thread (thought i'd posted it here)

Log pic:

stefanst

iTrader: (1)

You got sync issues!

A composite log may give you better info. It will tell you if the Cam or Crank sensor is the problem. Or maybe both...

Schuyler

iTrader: (1)

The signal I'm losing is the green line. Fiddling with the pots seems to have given me a few hundred extra rpm. I had reset the main board pots, but left the three added turns on the expansion r11. Which pot would have influenced this signal?

(No WiFi to post composite log)

Schuyler

iTrader: (1)

I've fixed it. I honestly just played with the pots on the expansion board, revving the car up every few turns until it worked. Now to figure out my idle and get rid of these WOT lean spots.

DNMakinson

iTrader: (3)

Good Deal
Yes 511 Hz

Idle PWM % will very for the same RPM due to the mass of variables involved in idle, including Alt load, temp, and things beyond me. So hence the need for closed loop to alter the valve setting to maintain idle.

I prefer to "Use initial value table" rather than "last value"

Suggest you use CLT, not MAT for the idle speed set point from value table.

Schuyler

iTrader: (1)

I'd been using use last value because the car can't seem to figure out what duty % it needs to use, and corrects itself when it bogs way down (usually requiring it to go to 100%) , and then idles alright. With "last value" on, it seems to remember this and hopefully behaves next time I come to a stop. Though after driving for 20 miles or so it seems to change values and want to stall when I come to a stop once again. Car wouldn't crank this morning, so I had to take another car to work. I will try to tackle whatever is causing it not to crank (i have an idea or two), and then try to do some work on the idle. I'm thinking I might need to open the idle screw some more? 100% should be a much higher rpm than 1000.

Braineack

iTrader: (62)

why aren't you using the intial duties table?

ive said it like ten times now, 100% DC should be like 3000-4000RPM.

Schuyler

iTrader: (1)

Will switch to initial duties table this evening and turn idle screw until 100% duty is 3000rpm or so.

Braineack

iTrader: (62)

good luck getting the RPMs back to 800rpm until you figure out why the MS isn't commanding the valve correctly

Schuyler

iTrader: (1)

What would you suggest my next course of action be? Aside from changing diodes, I'm out of ideas to handle things on MS' side. 100% in idle valve test has me at like 975rpm.

DNMakinson

iTrader: (3)

So you're thinking that the MS is saying it is delivering 100%, but that the valve is not really opening 100%?

Certainly forcing the idle up with the screw will be a good test for that. As you say, if it will not go back down, then that is a good data point.

Is it possible to idle on screw opening alone (pulling the connector from the control valve). Can that be used as a maximum screw opening at, say 700 RPM?

Yeah, like mine runs 650 RPM with valve closed.

Braineack

iTrader: (62)

that's what im thinking, yes.

Schuyler

iTrader: (1)

I definitely agree the MS is not opening the valve all the way, because it ran fine and idled up to like 1150 with A/C on on the stock ecu, before the idle screw was ever fiddled with. I just can't figure out what is causing this. Maybe changing the frequency is another idea?

Braineack

iTrader: (62)

remove the diode and see how it reacts.

stefanst

iTrader: (1)

Did you check your flyback diode if it actually works (multimeter test)?