Alright, I was kinda hesitant to make this post because I'm sure there's already a thread somewhere I may have missed that explained this issue, but as said in the title, I'm combating a lean idle and hesitant revving after setting up my speed density. I've watched countless videos and looked through a ton of forum posts and can't really find anything that will fix my problem. The forum posts I've seen have been abandoned halfway through troubleshooting, and the videos haven't been specific enough for my case. Please, no "just have someone tune it", I want to learn at least the basics here.

With that out of the way, I'll share all the settings I have currently and a log from yesterday. I have a general idea of what I may need to change, but I just wouldn't know how to make the changes.

As for the hesitant revving issue, I think it has something to do with "BaseTipInTPSAdj" in the direct access section? I bumped the first 3 sections up by 1, but honestly, that just made the revving worse. Before the change, it would sputter like it was about to die, then it would come back up and rev. Now it just dies. ECMLink's website is very vague on how to adjust that, basically just saying that you should increase it if you're having hesitant revving. By how much should I increase it? I saw a video on this, where he drove around stomping on the throttle in different ways to see what he needed to adjust. But uhhhh I can't do this because the idle/dying/revving issue. I certainly wouldn't roll that far before it dies .

For this idle issue, it'll fire up nicely, idle for a good 10 seconds around 12-15 AFR, then come back down and it won't catch on the idle I set it to. It'll come down, sputter, and die. I watch the wideband while this happens and it goes full lean and displays 3 dashes on the gauge (too far lean for the sensor to display). I did get it to somewhat idle yesterday after changing the coasting FC offset. I had that set to 190 from when I had set a higher idle in Link. Changed that to 0 since my idle is set to 900, and it would catch the idle at 900 but it would be at 18-20 AFR.

I want to get these things dialed in so that I can get some other things done. I need to bleed coolant, and change this fuel filler hose on the tank but the car isn't able to move out of the road until I can finish the idle tune. I will be doing a boost leak test soon once I get the materials to build my own, but I don't see anything obvious in the engine bay that would point to a boost leak. Just wondering whether anyone sees anything super obvious that I may have missed either in my settings or in the tune itself.

Mods:
16g turbo, 2.5in downpipe to 3 inch exhaust, Evo 560 Injectors, Aeromotive AFPR, Walbro 255, speed density, front mount intercooler and hard piping, DSMLink V3, AEM Wideband gauge, Boost gauge, and AEM oil pressure gauge

Attached to the post is my log with one rev to keep the car alive, and all my settings at the time of that log.

I appreciate any and all help. Thank you in advance for your patience .

-Kyle

Is it possible to reinstall a MAF? Then reset the tune to stock and change the parameter for your injectors. See how it runs that way and reintroduce SD if it's running better.

dwb said:

Is it possible to reinstall a MAF? Then reset the tune to stock and change the parameter for your injectors. See how it runs that way and reintroduce SD if it's running better.

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Yep! Just did that, here are the logs.

The first log (05) is with forcing closed loop (forgot to turn that back off) and stock MAF, the second log (06) is just the stock MAF plugged in.

I also figured out that I could get it to idle by forcing closed loop and switching back to 0% global fuel instead of the -20.3% I had. I got the -20.3% from ECMLink's website that says to use that when running Evo injectors. Not sure if this info is important or not, just wanted to throw that out there.

Was there much change between MAF and SD?
What's your base fuel pressure (measured with no vacuum line on the FPR)?
Have you observed fuel pressure while giving it throttle?

dwb said:

Was there much change between MAF and SD?
What's your base fuel pressure (measured with no vacuum line on the FPR)?
Have you observed fuel pressure while giving it throttle?

Click to expand...

Actually yes, I noticed it would rev freely with no hesitation and it idled around the AFR it should. If I remember correctly it idled around 13-15 AFR and it got rich at times. I did notice it was idle surging too, not by much but it was noticeable. Maybe this whole thing is a boost leak? I’m making a boost leak tester this week so hopefully that’ll rule it out.

I set fuel pressure this morning to 43 PSI without the vacuum line on. I saw fuel pressure increase about 5-8 PSI when I revved it which I thought was a little weird because I thought it should be 1:1 with boost. But maybe that’s normal, I’m not sure.

kyler021 said:

I set fuel pressure this morning to 43 PSI without the vacuum line on. I saw fuel pressure increase about 5-8 PSI when I revved it which I thought was a little weird because I thought it should be 1:1 with boost. But maybe that’s normal, I’m not sure.

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Yes, 1:1 with boost is right but vacuum has the opposite effect. 43psi at idle with vacuum pushes the base fuel pressure way higher, like you saw under throttle because your intake pressure was closer to atmospheric.
Try this. Use the 'activate fuel pump' option to operate it without the engine running. Now set the AFPR to 43psi.


Definitely take care of any boost leak(s) you can. Charge the system with the same or greater pressure as the boost you (plan to) run.

dwb said:

Yes, 1:1 with boost is right but vacuum has the opposite effect. 43psi at idle with vacuum pushes the base fuel pressure way higher, like you saw under throttle because your intake pressure was closer to atmospheric.

Click to expand...

Ahh this makes sense. I was wondering why it was doing that.

dwb said:

Try this. Use the 'activate fuel pump' option to operate it without the engine running. Now set the AFPR to 43psi.

Click to expand...

I will definitely do this when I can get back out to the car! Thank you for the advice!

Today I made sure my fuel pressure was set and that all seems to be good, sitting at a nice 43PSI. I also did a boost leak test and I had a couple of leaks coming from vacuum caps on my throttle body. I fixed that and that's all I could seem to find in terms of boost leaks.

I fired it back up today after the leak test, and I put it back to my speed density setup. I got two logs, 01 is with my injectors set at -20.3% global and the second one (02) with my injectors set at 0% global. In the second log, the idle was surging a little bit (I have yet to figure out what's happening there but I think it may be my charging system?) But the idle felt good and it didn't die on it's own. Any explanations here? ECMLinks website says to run Evo 560cc injectors at -20ish global fuel. Is the only explanation here that I have a boost leak I can't seem to find? Or could this be adjusted in the tune?

Here are the two logs:

Are they pink top injectors?

Idle surge isn't always a boost leak. BISS, FIAV, ISC, TPS and idle stop come to mind.

dwb said:

Are they pink top injectors?

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Yessir! According to that website, they're these:
Pink – 560cc – EVO 8-9 – Stamped MDL560P, casting # INP-401 – Low Impedance

dwb said:

Idle surge isn't always a boost leak. BISS, FIAV, ISC, TPS and idle stop come to mind.

Click to expand...

Gotcha, I'll look into that. I ordered everything I need for a throttle body rebuild yesterday. I'll make sure everything is readjusted properly after the rebuild. I noticed in the log that the TPS voltage seems normal.