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Author Topic: Help with 2.7T ME7.1.1 tune  (Read 2987 times)
BriefObsessions
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« on: January 08, 2025, 05:04:24 PM »

Edit: Sorry, this should be in the Diagnostics section, mods feel free to move.

Hi all,

I'm attempting to replicate the ME7.1 nefmoto community tune onto ME7.1.1 (C5 Allroad TIP). I understand there are some differences, in particular the PID behaviour - http://nefariousmotorsports.com/forum/index.php?topic=12352.0

At this stage all I'm trying to do is add some boost via LDRXN and some fuel at WOT with LAMFA (plus a little timing adjustment). Here's how that looks



This has resulted in a flat spot at around 3000rpm. Happens on every pull, some worse than others and more noticeable in 3rd compared to 2nd. Car pulls nice up to 3k, falls on it's face, then pulls nice again up to redline. You can see in the graph below the RPM's drop a little when this happens, seems to be right before actual boost reaches desired. The calculated AFR is concerning (15.6!), but is that the cause or an effect?



And a huge drop in power


The desired boost follows actual nicely, so DV's and N75 seems to be working as they should. Though there appears to be a fuel cut based on injector DC




Is this an intervention of some kind? Logs attached have a 2nd gear pull uphill that wasn't bad at all, followed by two 3rd gear pulls. Greatly appreciate any assistance.
« Last Edit: January 12, 2025, 09:11:56 PM by BriefObsessions » Logged
thedrill
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« Reply #1 on: January 08, 2025, 07:05:03 PM »

Did you close the spark plug gaps down to 25 thou? also Check your EGT sensors for codes.
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BlackT
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« Reply #2 on: January 08, 2025, 07:18:53 PM »

Fuel pump or bad spark plugs/coils

Log lambda voltage
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BriefObsessions
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« Reply #3 on: January 08, 2025, 09:26:32 PM »

Thanks for the quick reply's...

Did you close the spark plug gaps down to 25 thou? also Check your EGT sensors for codes.

I haven't checked plugs. EGT's are coded out for now until I can repair/replace them.

Log lambda voltage

Lambda voltage was logged, wouldn't it be open loop at WOT and referencing LAMFA map?

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BriefObsessions
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« Reply #4 on: January 08, 2025, 11:10:40 PM »

I'm maxing out misopl1, so look's like I need to tweak KFMIRL.
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BlackT
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« Reply #5 on: January 09, 2025, 02:51:41 AM »

Your lambda voltagr under WOT is under 0.5V that mean you have no fuel, your fuel pump is bad
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BriefObsessions
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« Reply #6 on: January 11, 2025, 01:17:09 AM »

Yeah you're right, the injector on times are way high too. Time for a fuel pump upgrade.

Thanks heaps.
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BriefObsessions
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« Reply #7 on: January 23, 2025, 01:21:55 AM »

Well it's not the fuel pump. I replaced it with a Walbro 350lph, along with a new fuel filter and FPR for good measure. Still have power loss around 3000rpm.
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BlackT
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« Reply #8 on: January 23, 2025, 01:40:11 AM »

Log again
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BriefObsessions
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« Reply #9 on: January 28, 2025, 08:13:48 PM »

Still some kind of fuel cut. I don't understand the injector DC drop (sample 2240).

I also have bad overboost happening causing the throttle plate to close, but that's after the initial drop in power.
« Last Edit: January 28, 2025, 10:29:35 PM by BriefObsessions » Logged
BlackT
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« Reply #10 on: January 29, 2025, 10:37:36 AM »

Still no fuel, did you put some cheap aftermarket pump?

You need to check pressure of fuel u der WOT, or get wideband
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BriefObsessions
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« Reply #11 on: January 29, 2025, 03:30:58 PM »

Link to pump

If it was the pump, why does the injector duty cycle drop?
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BlackT
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« Reply #12 on: January 30, 2025, 12:43:15 AM »

Link to pump

If it was the pump, why does the injector duty cycle drop?
nope, you get lean condition before injector drop
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BriefObsessions
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« Reply #13 on: January 30, 2025, 02:33:48 AM »

Hmm... Surely that pump would be sufficient.

Injectors?

Thanks for your help by the way.
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prj
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« Reply #14 on: January 30, 2025, 04:48:15 AM »

Put the computer away, and:

1. Get WBO2 (with linear out, so it can be fed into the ECU as well for logging).
2. Attach fuel pressure gauge and verify that pressure is fpr+boost during WOT.
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