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Resolved Issue tuning with ECUflash

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gst_Jake99

Proven Member
34
4
May 3, 2016
South Mills, North_Carolina
Running full rich no matter what?:idontknow:
I have reviewed countless ECUflash threads, including the How-to's. I have been unable to find a problem like mine however, and decided to seek some input from you guys.
Heres the situation: I am able to read and flash my ECU. Ceddymods is working, and with a stock tune under my SAFC-II, the car runs great. I am looking to remove the Apexi unit and tune strictly with ECUflash. There are no boost leaks, both o2 sensors and wideband are functioning, no exhaust leaks. I am running a 16g turbo, walbro 255, and FIC 750s.
I disconnected my negative battery terminal to clear existing fuel trims, disconnected the Apexi at the plug to eliminate any possible interference, set the injector scaling at 750 and the latency to 0.330 as suggested in the how to post. I flashed to rom, fired the car up and it runs pig rich. 10.0 on the wideband. So I upped the scaling to 850, same result. I even attempted setting the scaling to 1000 to try to get some sort of response from the A/F ratios. No success. (Yes, the MAF is plugged in LOL)
I am wondering if this is a tuning issue or a fuel pressure issue since I do not have an AFPR. What is strange however, is how well it runs on the apexi tune even without the regulator. Any input would be greatly appreciated.
Jake
 
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Is the car still showing rich after a few minutes of idling? Looking at past ECUFlash guides, they state to let it idle for a few minutes after updating fuel settings and to not pay attention to the a/f ratio during this time. You seem to be using the correct starting points for fuel setup with your injector size/type. I haven't used ECUFlash for a few years so my help is pretty limited. What I can tell you is with your fuel pump size, I would recommend investing in an AFPR to help keep things in check.
 
I have tried letting it idle. I've even attempted driving a few hundred yards down the road to see if things would clear up and it runs so rich that it sputters at 3k rpm at which point I pulled back in the driveway, put the stock flash back in and plugged the apexi back in. Before it started storming, I saw that under the ceddymods menu, there was a speed density setting automatically set to 1 (or on) I will uncheck that, and try again. I will definitely be getting an AFPR soon as well, I've seen good things about the aeromotive and had success using their products on my other vehicle. Would you guys agree?
 
If I remember correctly, when you hook up the AFC, you cut the airflow signal wire and run both ends to the AFC. Simply unplugging it is like unplugging your MAF. I would unplug the AFC and reconnect those 2 wires and go from there.
 
Update- Ive got the car running off of ecu flash.. weasel 1g was correct about the airflow wire. I've set my scaling and latency once again to match the ecuflash guideline. Cruise A/F ratios are good, idle was extremely lean. Now it seems to be having the opposite problem as before, so I upped the latency to no avail.. bumped all the way up to 0.405 and still having a lean idle. All 4 injectors are firing.
 
Is the car still showing rich after a few minutes of idling? Looking at past ECUFlash guides, they state to let it idle for a few minutes after updating fuel settings and to not pay attention to the a/f ratio during this time. You seem to be using the correct starting points for fuel setup with your injector size/type. I haven't used ECUFlash for a few years so my help is pretty limited. What I can tell you is with your fuel pump size, I would recommend investing in an AFPR to help keep things in check.

I would suggest getting an AFPR as well, especially with that big of a pump.
 
I would suggest getting an AFPR as well, especially with that big of a pump.
That will likely be the next mod then, at least for peace of mind and a solid fuel pressure reading if nothing else.
Any suggestion on why it is running so lean at idle? Front o2 functions, but sticks at very low voltage (0.05-0.01V) without cycling at idle, despite having latency cranked up.
 
Not to my knowledge. I checked all of the wiring leading to the Safc and didn't see any more connections like the airflow wire. Everything else was simply splice in (cant wait to get that **** outta there, rats nest from PO) The sensor responds when I apply throttle and matches the AEM wideband.
Ive currently got it tuned at 650 scaling and 0.99 latency (incredibly high:hmm:) but it is running better (safer and zero knock) now than it was on the apexi with trims in the +/-10 range, so I'm going to run with it until I'm able to install an AFPR. Battery voltage is good from a relatively new optima, perhaps I should get the injectors cleaned and flow tested as well to figure out that latency issue.
All in all though, ive made leaps of progress today thanks to you! I appreciate the help.
 
Last time I had an unexplained rich running system (idling 12 no matter what I did), it was my front 02 sensor. Logs were showing that it was ok but when I switch bought a new one just to test, BAM!! what-a-know 14.7. My suggestion is to pick up a front 02 just to check it and return it if same results.
 
Front O2 doesn't come into play until car goes into closed loop. His car starts up rich while in open loop and doesn't change when driving, which is most likely due to him just unplugging his SAFC.
 
Front O2 doesn't come into play until car goes into closed loop. His car starts up rich while in open loop and doesn't change when driving, which is most likely due to him just unplugging his SAFC.
Thats correct. As weasel mentioned, the airflow signal wire gets cut and both ends run to the SAFC unit. (Once the SAFC was unplugged, the ECU saw no MAF input and ran rich.) I soldered these back together and the problem was resolved.
I now have a driveable tune that I will be running until the pressure regulator comes in, then I can fine tune and get everything dialed in.
 
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