Cranking help DIYPNP 92 Miata
 

92 Miata Turbo. I got the car running on DIYPNP but it takes good 10-15 sec long cranking and throttling to get it to fired up when cold. After that it starts normal.

What do I need to check in TunerStudio so it fires up like it does on stock ECU.

what map and injectors are you using?

Stock injectors. 240cc map which I have tuned the fuel maps based on my car. Didn't touch the ignition map at all.

Used VE analyze for about 300miles.

My current tune is attached.

Also, isn't there suppose to be a fuel enrichment at cold start and the rpm should hold higher so car can warm up. As soon as I start it idles at 800rpm

I dont like a lot of settings on your map.

First, changing cranking rpm from 200 to 350RPM will help with starts.

Second, you sit at 800RPM after cranking because of your idle settings. You've given the idle valve a range of 6% and 37% PWM duty cycle to work within. Problem is, the valve is nearly closed at 30% and fully open around 65% (give or take). So if you log at logs, you probably always have your idle valve at 37% and it's never hitting your targets or really controlling idle.

so under "closed loop idle settings" change Open Duty(%) to 65 and Closed Duty(%) to 30. See how that goes for you. You'll also notice you DO have a "Closed Loop Idle Targets Table" which is the RPM you are trying to hit as a certain RPM, plus a "PWM Idle Cranking Table" which is what vlaue the idle valve positions at during/after cranking and decays out slowly based on what's dictated in your idle settings. Notice your map is trying to open the valve up much more than you allow...preventing fast idle speeds.

Brain,

Does my ignition table looks good?

When I use VE Analyze does it tunes fuel map only or ignition table as well?

it's fine. Just more ignition advance at idle than I think we need; I run closer to 10°.

Just fuel, ignition table is perfectly sufficient and safe to run. Fine tune fuel and idle control, and you're pretty much done.

If you don't mind can I see your ignition table?

That's what all the boys say. I believe the constitutes sexual harassment.




















https://www.miataturbo.net/attachmen...ine=1353516851

So what do these number mean? Degree of advancement? This table seems like 15.0 at idle. Is that 15 degree advance?

Or do I check with the timing light.

I followed the write up and did my fixed timing at 10 degree which was off so I had to use trigger wizard to pin point the timing to 10 degree. Once I burn it and switch it back to "use table" the timing went advance. It was no longer at 10 degree. Which I believe it's suppose to do because now its using the table.

correct.

im currently not practicing what I preach. just assume the 15° cells say 10°. I mean otherwise, it's more or less the same as yours.

worry about the other pertanent things.

I made the changes as you suggested. Will test it out and post results. Thanks for the great support by the way.

Ok cranking got better with changing the cranking rpm but the "Closed Loop Idle Targets Table" still isn't kicking in. Does this have anything to do with TPS not being hooked up?

It still idles at 700-800rpm and wants to stall. Not holding above 1200rpm as it should according to the target rpm in "Closed Loop Idle Targets Table"

yes, there's a parameter in the Closed Loop Idle Valve Settings for "Idle Activation TPS Threshold(%)"

your map is set to 2%, so if the TPS is not under 2%, you wont go into closed loop idle.

What does your TPS value typically sit at when you idle? if it's above 2% you need to recalibrate it, under tools > Calibrate TPS, in a way that holds it at 0%.

Did you build the DIYPNP or buy it directly from DIYAUTOTUNE.com? I ask because even with the TPS disconnected, if you dont add a 1K resistor to ground on the TPS signal, the input will float and you might see yout TPS value constantly tick up to 100%, that might be your issue here.

TPS shows nothing. My TPS is disconnected. I built the kit myself and I did put in a 1K resistor to ground.

So what do I need to correct?

the TPS gauge should be showing something, if anythign 0%.

Yes it sits at 0%.

Under calibration its set to (0 & 1023)

do you never get the green CL idicator when idling?

Yes I get the green CL. This is a screenshot of a cold start after sitting for 3 hours.

turn on the idle PWM% gauge. what's it doing? your PID settings probably need adjusting, specifically more I value.

Please see attached idle PID screenshot