Stalling right after a start
 

Good afternoon all,

I do appreciate the support here, and I am learning from your assistance!

I have my idle doing very well when warm, but I do have an issue that seems to be constant on both warm and cold starts. Starts right up, idles fine for about 5 seconds, then stalls out.

I am sure it is a simple adjustment that I am missing, but any help is welcome!

Cold and warm start logs attached.

What are your after start enrichment values? On the second crank attempt your AFRs go from 7.7 to 20 after ASE stops.

https://www.miataturbo.net/attachmen...ine=1451369227

I need to read up a bit

then the problem isn't ASE...


what injectors are you running and what is the req_fuel set at?


when youre idling at like 17:1 AFR and 1200RPM you have about 35% more fuel being added by enrichments and it's still not enough fuel.

op is on stock injectors. something is all janky in the settings

Yeah- those logs were on stock injectors. I installed flow force injectors yesterday and am running well.

Same issue though- 7 seconds after I start- idles up and then just dies. If I blip the throttle as the rpms are dropping, it catches and idles perfectly.

It seems like something in WSE I need to play with.

you have to pretty muhc double your fuel map. (so idle load cells are in 60% value) and you need to plug in better deadtime values/curve for those injectors.

Thanks brain. I plugged in the dead time when instilling the FF's and they are working sweet after some tuning.

Okay- figured out it is in the transition into Closed loop idle. I changed my PID delay from 8 seconds to 3 and now it will stall in exactly 3 seconds. Getting closer.

Mine does same thing only on first couple starts after an 30 min plus even if it's still 140 to 160 coolant.
Sub for solution good luck.

I saw that in the logs. run the iac test, my thought is the valve might be backwards, ie rpm going down; ECU closes valve instead of opening it.

Get idle perfect first with CL off, in warm up only. Then tune CL idle.

dont use warmup only. just tune CL.

On the 11.31.00 log

after the first crank, it's trying to basically peg the idle valve open because your idle targets are 1200-1500RPM during warmup, but it's idling at 1000-1200.

after the second crank it looks pretty normal. You start idling in the 30-40 idle pwm% area as the RPMs come back closer to 1000rpm. But eventually at the end of the log your idle valve is pegged closed and youre still not idling under 1000RPM as well as your idle advance is pegged it's max retard to lower your idle speed.

Have you ever messed with your idle bypass screw?

Get the fueling under order first -- its a big factor. Your base idle settings work very well out of the box for the majority of user.

Thank you Brain! I have not touched the idle screw, but a prior owner may have. I will spend some time on it today and try to get dialed in.

I am making some progress on the issue. The stall happens in the transition to idle VE, if I turn that off, no stall when starting.

I am looking to understand idle VE better, but if I understand correctly, it is a micro fueling map for idle cells only?

The values in there are substantially smaller than the idle cells in my VE table- I assume they should be pretty close to what I have on my main VE table?

Sorry for the total n00b stuff, I am reading in the tuning manual now.

Happy New Year to all!

correct.

you need to double that table as well.


values should be in 60% area, not 30%

Brain- you are a stud and I am a n00b!

I was not understanding the idle VE- but my car was trying to go into CL and dropping from a VE table around 110 to 34. No wonder it was not stable! I played around with it, car is now going into CL and idling at 13.5 or so. Nice.

I suspect I have work to do- but this is my table now. Pretty flat. I am still getting more idle droop than I like with headlights/heater blower, but that's for another day.

Feel free to rip on my table!
Attachment 158417