ECMlink o2 not cycling after MAF comp change

[rconlon67]

working on getting everything running correctly at idle. I took a log on Saturday (attached, 04.24-03) and my O2 sensor seems to be cycling quite normally. After the log, I did the "MAFComp adjust (combinedFT)", adjusted the sliders to the suggested values, then wrote to ECU and closed it up as I was out of time.

Yesterday, 04/25, I went out to get another log and my O2 sensor seems to have stopped cycling (attached 04.25-01 and 04.25-02) - is it possible it died? seems like I may have broke something.

Lost on what to look into next and would appreciate any pointers.

Thanks in advance,
Ryan

 

[ATF 2GTalon]

It stopped cycling because it dropped out of closed loop and went into open loop. I can't tell what would have caused it to go into open loop. Not enough information in the log. Possibly you pulled the MAFComp too far negative in the 50hz slider. What size injectors are you running? I'm guessing you have the wrong size injectors inputted into the fuel tab and you are compensating with MAF Comp. The airflow per rev is way too low. Reset the MAFComp sliders all back to 0, and correct your global and deadtimes first. Set global to the calculated value for your injector size. Then use deadtime to richen or lean the car to get it to idle right. Then post back a log.

 

[rconlon67]

PTE 1000 cc injectors. I will try setting to 0 and report back. Anything else I should specifically be logging for this exercise?

Thank you!

 

[Vegas Smith]

The only thing I can hypothesize is the o2 sensor just dies or the ecu loses signal.

 

[ATF 2GTalon]

Not much more available to log. Maybe just adding Battery voltage to the log. If you have a MAP sensor that would be nice to have too.

If you can set the global correctly to 1000cc that should help pull more fuel out and you wouldn't need to go so far negative with the MAFComp. So just start over, set 0s to MAFComp out for now and only use deadtime to get the idle to cycle around 14.7. Then post the log and let me see what the next adjustment steps need to be,.

 

[AWD-Tony]

I’d bet it’ll start cycling once he bring up the 50hz sliders. He’s at .15 airflowperrev

 

[rconlon67]

Thanks for all the ideas!

So I adjusted the sliders and started the car up again. Car seemed to act very similar, but the log shows it seems to have been stuck in open loop mode to start (odd, not sure what causes this but I will investigate/research), then kicked into closed loop and the O2 sensor was cycling as expected (yay!), but seemed like the ECU "learned" or adjusted and the O2 eventually stopped cycling(boo!).

Does this make any sense?

Are there any parameters that stick out as being something to look into?

 

[ATF 2GTalon]

Startup in open loop is normal. It switches to closed loop once o2 has warmed up and coolant gets up to a certain temperature. Blipping the throttle will also put it into open loop when you let off the throttle. This is normal. It should switch back to closed loop once the injectors kick back on to maintain idle.

As I menioned before reset your MAFcomp sliders to 0. You have them set wrong anyway, so just start over at 0. Are you paying attention to your wideband and the STFT? It clearly wants more fuel. Once you have Maf Comp zeroed, only use deadtime to richen or lean as needed. Look at your wideband and stft to help guide you which direction to go. Do not change anything else. Only change deadtime.

If you are not going to listen to the directions I am giving I will stop replying. I am starting to understand why so many people have stopped helping with dsmlink questions.

 

[AWD-Tony]

Your O2 stop cycling because it needs more fuel in closed loop. Like Joe said, it will always first start in open loop. Take the time and read the link below.

fueltrimupdatepoints [ECMTuning - wiki]

www.ecmtuning.com

 

[rconlon67]

I don't mean to frustrate anyone, sorry. Thank you for the feedback, I zero'd out the MAF as you recommended, logs attached:
-02 warmup deadtime @ 540(~7min),
-05 deadtime @495(~3min),
-06 deadtime @ 480(~lile over a min)
I have read over the fuel trim updates previously and again today.
My basic understanding is the WB should be cycling around 14.7(Wideband=AFR), which it seems like it is, and the STFT seem to be cycling above and below zero by a few percent

I am obviously not understanding something, What am I missing?

I think the high level concept is clear but I am too novice to know exactly what is "good enough" or if more tweaking should be done.

 

[ATF 2GTalon]

This is looking a lot better. Do you feel that the idle is smoother than it was previously? But it looks like your airflowperrev could still be brought up higher. Go to the MAF Comp and set the 50Hz slider at 6.2%, 150Hz at 4.7, 250 at 3.9 and 400 at 3.1.

Once you save this, the car will want to run rich. Then use deadtime to richen or lean to get stft back close to 0%. After that you should be able to drive around the block a couple of times and see how driveability is and get a longer datalog for me to check.

 

[rconlon67]

The car seems to be running as smooth as it has in a very long time, I will adjust the maf comp as described and work on the dead time.

After a few short trips around the block I will report back. Probably this weekend.

Thanks again!

 

[rconlon67]

Not sure if I should start a new thread, but have had the car out for a few short trips around he block. This past Friday, it felt good enough for a ~10min drive. Logs attached.

1)I think I have a heat problem(223 degrees?), car was pushing coolant out of the overflow container. I will investigate this in parallel with the tuning.
2)The car seems to be running lean to my untrained eyes, any thoughts? Adjust he MAF up a few more percentage?

Thanks in advance.

 

[AWD-Tony]

Zero out your timing slider. Change the maf slider to below. Yeah, you'll have to figure out why it's getting hot.

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[rconlon67]

So been meaning to post an update.
As mentioned above, I had a heat issue I wanted to investigate. So I started with trying to verify the coolant system had enough coolant. I started the car with the radiator cap off, let it get warmed up and add any fluid if needed. While I was standing in front of the car watching the coolant, I noticed something out of the corner of my eye. It was a spark. I investigated further and found one of my sparkplug wires was mostly disconnected from the distributor (#2).

So I shut the car off, reconnected the wire and since then I have not been able to get the car to run smooth.

the car is cycling between ~1000 RPM and 1400RPM and jumping between closed loop and open loop. Going Lean in closed loop and then rich in open loop ( or so it appears to my novice eye).

I double checked my base timing, still at 5degree below TDC.
Checked throttle cable - still looks good.
Checked TPSVolts = -.63

I noticed my ISCPosition is at 0, so that is wrong, but LrndIdleAdj is sitting around 142, which seems reasonable.

I followed https://www.sixsigmatuning.com/dsm-idle-control on adjusting the ISC. I ended up turning the BISS all the way in and could not get the ISCPositon to move, but When I started the car the next time ISCPosition started at 57, but walked itself down to 0 within the first 30 seconds.

I thought maybe I should start over again with the tuning, so I zeroed out the MAF comp and tried adjusting the global fuel down. my thought was that if in closed loop it is lean, I need more fuel? am I off on this?

I'm sure ISCposition is a clue, but not sure what to do at this point.

Anyways, any advice or things I could try would be appreciated, feeling kind of stuck right now.

Thank you in advance.
05.29.04 - first log after plugging in the loose wire global fuel -48
05.29.12 - global fuel -30.1
06.04-01 - BISS all the way in - 30.1
06.04.05 - BISS all the way in global fuel -39.8

 

[rconlon67]

In case anyone is following along, an update, decided the only thing I didn't check was boost leak. Found a pretty significant leak at my PCV valve, Just a reminder to anyone trouble shooting to always go back and boost leak test. Ordered a new PCV, will update once that is replaced.