ECMlink Idle and e85

[zaderian]

General question and I'll try to post a log tonight.
Specs:
stock 2.0
FIC 850cc
E85
50 trim

I'm tuning a friends car and I have only barely begun to start tuning idle. My question is that when I start to use the MAFComp adjust tool the ecmlink is going to try to 0 out the ltft and stft but that seems to land us around 14-15:1 AFR on the gas scale. His car idles rather rough at this setting even at 1000+rpms. It really smooths out nicely around 13.5 when I increase the deadtime and doesnt do anything at all by adjusting the airflow sliders. We only get about 2 hours a week to tinker with the tune so I have not had a chance to see how this is going to affect the combine FT's. Is there a better way to get 13.5:1 while still maintaining as close to 0% combined FT? Grams per rev is about .28.

Sorry I dont have more info, I'll try to get some more info this weekend. Thank you for your assistance in advance.

 

[Soccerguy136]

1st: Those 850's are not what I would choose for a 50 trim and E85.

https://www.ecmtuning.com/wiki/baseinjectordata

Note that even @100% IDC, which you don't really want to use btw, is barely enough for a 50 trim since most of them are around 46lbs/min and higher.

Also, I assume that he has at least a Walbro 255. If not, he needs one ASAP. An AFPR wouldn't be a bad idea either as you could balance out the 850's by running a higher base fuel pressure.

2nd: If you are tuning with E85, you only use 14.7:1 for cruise and part throttle. For WOT on E85 you want to aim for between 11.5:1 and 12:.0:1.

I realize you said you are just starting to tune idle but I just wanted you to be aware.

Hope this helps.

 

[97gsxIA]

As per the topic of tuning your idle:

13's are too rich for idle especially on E85.. no matter how "smooth" it makes it.

Granted, it's not going to cause damage, but you'll see spark plugs and O2 sensors foul out pretty quick.

You should enter in the recommended global injector percentage scalar and deadtime settings. and then Lock the ECU in openloop.

Locking it into open loop will make it shoot for whatever your lower AFR cells are set to (I.E 14.7-15.1 ideally on E85)

You adjust your global scalar until it's spot on to what it's targeting.

Then adjust deadtime according to your CombinedFT after first setting your TPS and AirflowperRev to spec.

(Adjusting airflowperRev first will wack out your CombinedFT in which you compensate by using deadtime.)

To smooth out your idle without sending you AFRS to the pits.. you need to look at mechanical issues (most likely sealing issues with TB or poor IAC/ISC function)

Doing all of this will assure you decent idle THE RIGHT WAY.

Cruise and WOT tuning are a different story, and it looks like you should do some reading up on requirements and basic tuning techniques.

P.S. A bad ISC will cause a rough idle.. and if not corrected will fry the condensors on your ECU. Ask me how I know....

 

[zaderian]

The 850s are fine for his goals (about 350whp) and he is on a walbro 255 with an AFPR. He just installed a refurbished TB with a tested FIACV. We have since been able to smooth idle a little more with a mixture of 14.7:1. Were not encountering a new issue where it will not hold 14.7 in closed loop. Why would we disable closed loop all together?

Maybe I should also mention that he is using a GM MAF and not on SD.

I have attached a log. The only way I can get it to enrich it is changing the dead time to 500 which locks it into open loop.

 

[Calan]

I have attached a log. The only way I can get it to enrich it is changing the dead time to 500 which locks it into open loop.

1). There is no log attached, and

2). You can't easily "enrich it" in closed loop, unless you change the switch-over point of a simulated NB. If you are really reading 13.5:1 on a WB when warmed up and in closed loop, my guess is that the fuel trims are maxed out and the ECU can't adjust for stoich any longer. And, 13.5:1 in closed loop on E85 would be pretty rich.

 

[97gsxIA]

Scroll down, download the attached file on GM MAF configuration.
Your problem lies somewhere in your tuning process with the GM MAF.
They are real tricky to get in the sweet spot for closed loop operation.

v3mafadjcombft [ECMTuning - wiki]