hi all, i've been reading alot of threads about idle these past couple days, but still can't seem to get my idle sorted. background: mspnp2, 92 miata 1.6, greddy turbo kit, 560cc injectors, aem wb.

so the car runs and drives fine in/out of boost. had my buddy tune it on the dyno, but this was his first time with megasquirt.

the problem is, on startup with no throttle, the car will start, then run for maybe about 1 second, then die out. if i start it again, with a tiny bit of throttle, and hold it about 1000 rpm for a few seconds, till the wideband gauge starts showing numbers, it will then idle just fine.

i've played with the pwm warm up settings, and closed loop idle settings. i've played with the idle valve settings, but it doesn't seem to change my idle at all. from 35-100% duty cycle in test mode, doesn't matter. also, if i unplug my idle air control valve, underneath the throttle body, the idle does not change at all either. it reads 13 ohms between the two terminals on the valve. also, my iacv buzzes when its being modulated by the megasquirt. is that normal?

 

what are your after start enrichment settings set to?

 

here it is. when i change the graph points at the coolant temps im having problems with, no change in starting with no throttle.

 

idle that slowly dies out is probably too lean. try adding 10% to the temp range (+/- 20°) where you're testing and see how it works. If it improves, add 10% more. Repeat until smoooooove.

 

If idle valve settings don't change your idle speed, it sounds like your idle valve does not work.

But the problem you're having sounds like not enough fuel. Does the car die before or after the after start enrichment decays out? If it stalls immediately after, the fuel table is too lean in the idle area.

 

Remember there's warmup enrichment and after start.

 

no matter what i change my idle valve duty cycle, my idle does not change. unplugging it does not change my idle speed either. looks like i should start shopping for a new one.

my car still has the non variable tps, i wonder if that makes a difference.

just to clarify, when i say it starts, but dies. i mean it cranks, then runs for about half a second, then dies. maybe it fires once, but it does fire. increasing the pw at the current coolant temp, on both after start enrichment, and warm up enrichment does not make the car fire any longer.

changing the priming pulsewidth seems to make a very small difference, but it just seems to make it richer for that one firing event.

would the engine start if the idle control valve is not working?

car definitely dies before after start enrichment tapers out.

 

Noob question here. If it's too lean shouldn't the AF gauge show?

 

In theory yes, but unless you power the wideband externally from the car it's generally in warmup when you're in afterstart enrichment mode.

That's my experience with both the Innovate and the AEM widebands.