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jokers_greg jokers_greg is offline
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Default n54 Lean above 6000rpm - 08-17-2020, 06:48 PM

Hey guys,

I'm chasing a lean condition for a few weeks now and simply don't know where else to go. Here are my current mods:
LPFP: Single walbro 535
Fuel: 94 Octane no significant ethanol
Fuel 2: Pure methanol via 2 x CM7 nozzles
IC: VRSF 7.5" competition stepped
Couple of "stage 3+" DAW turbos (yeah yeah I know)
2" relocated inlets
PR coils
BMS Chargepipe with 180 degree nozzles + 3" lower chargepipe
4bar TMAP sensor
NGK 95770 plugs gapped to (iirc 0.020" possibly 0.022")

Car has never had a misfire in the years that I've owned it, no 30FF. Attached are my logs. At first I figured my injectors were the problem. Even though they were all index 12 I did not buy them brand new from a reputable store so I swapped the 3 in bank 2 with new ones from FCP euro. My lean problem still persists, everything looks good with the hpfp readings, same with the lpfp. Before I start spending money on replacing (possibly needlessly) my hpfp and O2 sensors maybe someone could suggest other diagnostics from my 3 logs.

Here's a Map 3 log in 3rd before changing the injectors:

So then I changed the injectors and ran another Map3 run. Still lean:

to isolate the problem, I tried a map 2 run (no meth). Still lean:
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Default 08-18-2020, 06:20 AM

Who is your tuner? They should be able to make the adjustments needed.

Don't be ashamed of your DAW 3+, I have the same ones and just ran a 149 in the half mile with them this past weekend.
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Default 08-18-2020, 07:21 AM

Quote:
Originally Posted by NoGuru
Who is your tuner? They should be able to make the adjustments needed.

Don't be ashamed of your DAW 3+, I have the same ones and just ran a 149 in the half mile with them this past weekend.
My tuner is triggz, actually he's the one that has been pointing out the lean AFR to me. Given that I'm still lean on Map2 I'm assuming some sort of lack of fueling.

Oh man, the turbo's have been great to me so far, just really want to figure out this issue and finally get them going past 24psi
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Default 08-18-2020, 07:37 AM

I can't read those logs you posted but seems strange you can't supply enough fuel.

I too have a Walbro 535 and that should be good up to say E60 so I don't think it is that unless your EKP is over heating.

What is the HPFP reading?
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Default 08-18-2020, 07:27 PM

Quote:
Originally Posted by NoGuru
I can't read those logs you posted but seems strange you can't supply enough fuel.

I too have a Walbro 535 and that should be good up to say E60 so I don't think it is that unless your EKP is over heating.

What is the HPFP reading?
Damn, it would be a lot easier if you could see them. Don't think I can send any links via 3rd party websites on this forum. I was able to open them from my other laptop

How can I tell if my EKP is overheating from the logs?
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Default 08-18-2020, 07:32 PM

In any case the fp_h stays around 11-13 throughout the pull on map2, and 14 at high rpm on map3
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Default 08-19-2020, 10:19 AM

The lowest I would ever let a HPFP get would be 1500.
I would replace it before it stops on you.
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Default 08-19-2020, 11:59 AM

Quote:
Originally Posted by NoGuru
The lowest I would ever let a HPFP get would be 1500.
I would replace it before it stops on you.
well I believe the readings are in increments of 150psi, meaning even at 11 that is 1650psi. So I don't think that is the issue
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THE BEAST THE BEAST is offline
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Default 08-19-2020, 12:39 PM

Which log is where it went lean ?
Post that one up so I can take a look
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Default 08-19-2020, 12:45 PM

Quote:
Originally Posted by THE BEAST
Which log is where it went lean ?
Post that one up so I can take a look
All 3 of them are too lean in the higher rpm. There are two map 3 logs (before and after bank 2 injector swap) and one map 2 log after changing bank 2 injectors so I could isolate the fueling from methanol.
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Default 08-19-2020, 01:06 PM

Quote:
Originally Posted by jokers_greg
All 3 of them are too lean in the higher rpm. There are two map 3 logs (before and after bank 2 injector swap) and one map 2 log after changing bank 2 injectors so I could isolate the fueling from methanol.
I looked at the first log. Is lean spool enabled ? I see it lean as it spools, but when boost hits target its fine.
Are you talking about during shift ? Because I dont see it lean at higher rpms on WOT.
Can you post the log that went lean and kicked you to map 4 ?
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Default 08-19-2020, 01:20 PM

Quote:
Originally Posted by THE BEAST
I looked at the first log. Is lean spool enabled ? I see it lean as it spools, but when boost hits target its fine.
Are you talking about during shift ? Because I dont see it lean at higher rpms on WOT.
Can you post the log that went lean and kicked you to map 4 ?
It hasnít kicked me to map4 (it isnít THAT lean) but if you look at the map2 log for example, I hit 12.8 AFR at 6800rpm which is leaner than weíd like. Given my fueling my tuner expects <12 at the top end. The boost has been dialed back in these logs because we dont want to go back to 29psi until we find the cause of the high AFR
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Default 08-19-2020, 01:23 PM

Quote:
Originally Posted by jokers_greg
It hasn’t kicked me to map4 (it isn’t THAT lean) but if you look at the map2 log for example, I hit 12.8 AFR at 6800rpm which is leaner than we’d like. Given my fueling my tuner expects <12 at the top end. The boost has been dialed back in these logs because we dont want to go back to 29psi until we find the cause of the high AFR
If you want it richer, your tuner would need to adjust for that in the tune.
What is he targeting at that rpm in the tune ?
Edit: I see where it got a little lean on one of the logs. I dont think its a hardware issue. Plenty of fuel but trims max out for a second.
Possibly 02 but IMO I dont think so. I would have your tuner check his tune and fueling scalars.

Last edited by THE BEAST; 08-19-2020 at 01:35 PM..
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Default 08-19-2020, 01:35 PM

Quote:
Originally Posted by THE BEAST
If you want it richer, your tuner would need to adjust for that in the tune.
What is he targeting at that rpm in the tune ?
Heís assured me he has done that already, and I do trust his expertise as a long time member here and a pretty prominent tuner in my area (Greater Toronto Area). Iím trying to figure out if thereís a mechanical issue that could lead to these readings. The usual suspects all look good in the log: lpf, hpf etc. and with new injectors I doubt those are the issue either. Iím grasping at straws for anything else I may have missed
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Default 08-19-2020, 01:38 PM

Yeah I was thinking about the O2 sensors, but wasn’t sure how they fail. I thought they’d be have more of an abrupt failure symptom rather than only reading slightly off. I also looked at my spark plugs which looked a little lean to me. Any pics of healthy plugs that have been running in a 550-700whp n54?
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Default 08-19-2020, 01:41 PM

Quote:
Originally Posted by jokers_greg
Heís assured me he has done that already, and I do trust his expertise as a long time member here and a pretty prominent tuner in my area (Greater Toronto Area). Iím trying to figure out if thereís a mechanical issue that could lead to these readings. The usual suspects all look good in the log: lpf, hpf etc. and with new injectors I doubt those are the issue either. Iím grasping at straws for anything else I may have missed
yeah, I get you. If scalars are fine, maybe 02 starting to go out ?
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Default 08-19-2020, 01:44 PM

Quote:
Originally Posted by jokers_greg
Yeah I was thinking about the O2 sensors, but wasnít sure how they fail. I thought theyíd be have more of an abrupt failure symptom rather than only reading slightly off. I also looked at my spark plugs which looked a little lean to me. Any pics of healthy plugs that have been running in a 550-700whp n54?
My plugs come out almost looking as if it were running lean, but its not running lean.
Not very tan like on typical old V8s. Pretty white but car runs fine and logs are solid.
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Default 08-19-2020, 02:21 PM

Quote:
Originally Posted by THE BEAST
My plugs come out almost looking as if it were running lean, but its not running lean.
Not very tan like on typical old V8s. Pretty white but car runs fine and logs are solid.
Hmm yeah mine arenít too too bad but a tad lean. I was leaning (pun intended) toward replacing the O2ís next but didnt want to throw that money at it unless I was certain everything else wasnít the cause. Is it possible for the hpfp to read beautifully but not deliver the correct flow? Would any blockage in the low pressure line show up on my logs?

I was going to tackle things like air filters or hunt boost leaks or test boost solenoids but any of those things would cause me to run rich, not the other way around.
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Default 08-19-2020, 02:46 PM

Quote:
Originally Posted by jokers_greg
Hmm yeah mine arenít too too bad but a tad lean. I was leaning (pun intended) toward replacing the O2ís next but didnt want to throw that money at it unless I was certain everything else wasnít the cause. Is it possible for the hpfp to read beautifully but not deliver the correct flow? Would any blockage in the low pressure line show up on my logs?

I was going to tackle things like air filters or hunt boost leaks or test boost solenoids but any of those things would cause me to run rich, not the other way around.
The thing is...plugs really should be read doing a run, wot, on top end shut down car, pull over and read plugs. You could run lean on top end, but rich on idle or low rpms. So....if you do wot pull, then still drive home a couple miles, read plugs, they would read fine or maybe even rich at that point.
As far as HPFP and LPFP, they are fine. If say you had a clogged injector. Hpfp would still read fine or higher since it wouldnt be running out of capacity with 1 or 2 clogged injectors, it would actually help boost #s on hpfp, but that would make you run lean.
The thing is the car is fine except for a second or 2 and trims max , then back to normal. I would replace O2s if it were my car and I was sure everything was fine on the tuning side.
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Default 08-19-2020, 03:14 PM

Quote:
Originally Posted by THE BEAST
The thing is...plugs really should be read doing a run, wot, on top end shut down car, pull over and read plugs. You could run lean on top end, but rich on idle or low rpms. So....if you do wot pull, then still drive home a couple miles, read plugs, they would read fine or maybe even rich at that point.
As far as HPFP and LPFP, they are fine. If say you had a clogged injector. Hpfp would still read fine or higher since it wouldnt be running out of capacity with 1 or 2 clogged injectors, it would actually help boost #s on hpfp, but that would make you run lean.
The thing is the car is fine except for a second or 2 and trims max , then back to normal. I would replace O2s if it were my car and I was sure everything was fine on the tuning side.
I could do that but have always been super OCD about driving gingerly after and letting enough fresh oil run through the turbos after WOT pulls. Iím sure trying it once wouldnít be too bad. The more we talk the more I find myself convinced that the O2ís need replacing. The problem is that duty surcharge of shipping things over the border from FCPeuro!
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