90 Turbo

iTrader: (3)

I really appreciate you folks. I know I would not have been able to get this whole diypnp thing working at all with out yall.

So here it is car runs and drives well.

But starts slow in the cold especially.
What adjustments do make to correct this and what effects does each adjustment have?

The idle seems fine at first but once warm it oscilates a lot. Going up to 2k then droping to almost stalling then back up.
It will be idling fine for 20-60 sec then start this then sometimes it just starts this?

Battery voltage is there an adjustment for the alernater. I never had any issues before but it just does not feel like my battery is being charge as completely as with the stock ecu?


Thanks I will post a log of both cold start and idle jumping if that helps. I am at the park with my kids in the suv so I can do one till this evening.

Thanks

Brian

Joe Perez

iTrader: (8)

Getting idle to be nice and stable can take some work. I find it useful to hand-tune the cells in the VE table around idle to ensure that they are all roughly equal, preventing large swings in AFR as the engine moves around in this area.

I'm confused by one thing:
In your signature it says that you have a 1990 car and does not mention an engine swap. Unless you are running the alternator from a '99 or later Miata, your alternator is internally self-regulating. The ECU shows you what the system voltage is, but it does not control the alternator.

90 Turbo

iTrader: (3)

Thanks Joe. If I set the Ve in the that section of the table how I tell Autotune to leave it alone? Or do i just set all the afr table the same and let auto tune make the ve tables
the same? if so what afr am I looking for at idle?

No engine swap here so I guess the diypnp is not effecting charging.

What about cold start? where do i start on tuning that?
What should my settings be. Should I be on pwm closed loop?

My cranking rpm shows as 200 in the cranking settings tab si that right?

Braineack

iTrader: (62)

should be 300-350

90 Turbo

iTrader: (3)

Thanks Brain
What effect does this setting have?
I am trying to wrap my head around what all these things do so I dont have to ask so many newb question

Joe Perez

iTrader: (8)

Within Autotune, set Min RPM to a value which is below your normal idle RPM. And keep an eye on the values in those cells. If you set Min RPM to a value which is between two columns, AutoTune will still make changes to the column just to the left of the sutoff due to interpolation.

IOW, assume you have Min RPM set to 1200, and that falls between the columns for 1000 and 1500. If RPM is 1300, fuel is being influenced by both the 1000 and 1500 columns. AutoTune knows this, so it will distribute its correction into both columns. It's not technically disobeying you, it's just behaving in a way that might not be obvious.


A cold day.

Craning fuel isn't a highly critical setting. If the engine starts, it's good enough.


Which settings?


It's a value that the ECU uses to make a judgement call about whether you are cranking on the starter or not.

When RPM is below this value, fueling is based on the Cranking PW table, and MAP is based on the Cranking MAP entry. Once RPM rises above this value, the engine is considered to have started, so fueling shifts over to the VE table, warmup begins, and MAP goes back to normal.

You should set this to be about 50-100 RPM higher than normal cranking. 300 seems to be common setting.

90 Turbo

iTrader: (3)

Here is a log between lights after the car is warm. You can see it surging I just dont know why?

EunosBen

Looks like PID lockout there, once the CL control kicks in the idle actually becomes stable, where its up and down the Idle valve is sat at its closed value.

Read this:
http://www.msextra.com/doc/ms2extra/...nual.html#idle

and this

http://www.msextra.com/doc/ms3/Idle_Control.html

Then follow these

1st: http://www.mx5nutz.com/forum/index.php?showtopic=46748
2nd: http://www.mx5nutz.com/forum/index.php?showtopic=46823

Once done, report back with logs & MSQ.

90 Turbo

iTrader: (3)

Man enous thanks. I will get to work but does my 1.6 90 have an iac valve and where/how do I unhook it?

Joe Perez

iTrader: (8)

Yes.

It's on the underside of the throttle body.

You use a small screwdriver to lift the wire clip which retains the connector, and then pull.

Did I miss something earlier in this thread which explains why you'd want to defeat your IAC valve?

Braineack

iTrader: (62)

^^ this.

90 Turbo

iTrader: (3)

White with red stripe. got it! thanks

Ok so I have completed this page
http://www.mx5nutz.com/forum/index.php?showtopic=46748

what idle control/algorithum do I pick at this point.
on/off
pwm closed loop
another?

I cant tell from the instructions. I do see that the next page
http://www.mx5nutz.com/forum/index.php?showtopic=46823

is for pwm closed loop and it says do first instructions first then change to pwm closed loop but what algorithum is the first step?

90 Turbo

iTrader: (3)

OK i guess I will try pwm warmup

Joe Perez

iTrader: (8)

You want PWM closed-loop.

On/off is not relevant to us; that's for older style "idle-up" valves which are not variable but are just open or closed.

PWM warmup runs the valve only during the warmup period, using a fixed duty-cycle table, and then shuts it off, so you have no idle control after warmup.

PWM closed-loop operates the idle valve all the time, actively seeking to maintain a specific idle RPM (which varies from "fast" to "slow" as the engine warms up).

90 Turbo

iTrader: (3)

Thanks Joe.
You are right none of the other setting seem to work.
The pwm closed loop works for a while but if you leave it idling longer than 1-2 minutes it starts oscilation like crazy. I tried the method mentioned above of setting all the afr to the same value and setting the timing to fixed 16 in the idle range but it still does it. The funny thing is it did not do it while I had the isc valve unplugged. I guess these instructions
http://www.mx5nutz.com/forum/index.php?showtopic=46823
are next but it says if you dont have a steady idle to start with you will just be chasing your tail which is all i seem to do with idle.

Joe Perez

iTrader: (8)

I'd like to see a log and an MSQ.

One thing that often happens is that you wind up oscillating between VE cells with greatly different values. It helps considerably to edit the RPM scale on your VE table such that left-most column has a value which is slightly higher than your normal idle RPM.

Here's an example:



See how the left-most column has been raised from the default of 800 to 1000 (you could even try 1100, if your normal idle is higher than 1100)? Also, the kPa rows for 26-60 are all the same value? This ensures that once it hits the target speed, it's in a part of the VE table where it's no longer interpolating, and we can be sure that the VE value is going to be rock-solid.

I'm not saying these exact numbers will work for you (in fact, I can guarantee they won't, since they rely on a heavily-cheated Req_Fuel value), but you should try massaging your VE table a bit to achieve this concept.

Same goes for the spark map.

Basically, you want to remove spark and fuel as variables from the idle equation. Lock them down so that the behavior of the IAC valve is the only thing we need to worry about.

90 Turbo

iTrader: (3)

Well I think i have it tuned a little thanks all for your help
One of the things I figured out was these are the idle instructions for diypnp

http://www.msextra.com/doc/ms3/Idle_Control.html

I always get confused which of the many manual apply to diypnp seems like sometimes its ms2 other like the idle are ms3
anyway thanks
My final setting are 50 p 5 i and 0 d
I changed the idle to activate based on the above instructions thou I used 2 as the tps threashold

90 Turbo

iTrader: (3)

Joe thanks you really help me with this I appreciate it.
Here is msq I tired to get my spark/afr/ve to be the same thru the 700 to 1500 rpm range

Braineack

iTrader: (62)

the MS2 and MS3 idle code is more or less the exact same.

90 Turbo

iTrader: (3)

well this morning it was 50 degrees I did not have the idle up I was hoping for. Basicly I think having the I so low is making the idle up feature not work at all but if I turn it up I get oscilation. I am going to turn the bleeder valve down and see if that helps with oscilation.