zz4x4

Hi All,
I have a 2013 LY5 swapped into a classic Land Rover and I've been fighting lean codes on both banks for many months. The harness and ECM are from Speartech and the tune is a stock 2013 tune. My LTFT is steady at 24% on both sides. The STFT jumps up with the RPMs but then slowly starts to drop as does the LTFT even though the RPMs stay high. When it goes back to idle the LTFT rises back to 24% and the STFT goes to zero. I've looked for intake leaks but have found none. I've done a smoke test, propane test, pressurized soapy water test, and stethoscope test. The intake holds static pressure and vacuum for a good while. I've disconnected and plugged the various intake ports such as PCV, EVAP and brake booster with no effect on the issue. I'm pretty confident there is no intake leak. The MAF is a new delphi unit. The exhaust system is tight with new gaskets and no noticeable leaks. I have Hooker block hugger shorty headers and the stock O2 sensors. The O2 sensors read .1 to .8 V and seem to be functioning correctly. I tested them with propane and they jump to .9. The engine runs and drives fine with no hesitation or issues. So what in the world is causing the Lean Codes?? Could it be the tune needs to be adjusted? What would be the next thing you would do to try to solve this?
Thanks for any inputs,
Jeff

Floorman279

iTrader: (11)

leaking at the map sensor? how are your map readings

G Atsma

Looks like you need a good tune.

s30.hybrid

iTrader: (3)

Che70velle

iTrader: (6)

dreadpirateroberts

iTrader: (1)

MAF sensor could be bad from the manufacturer, or clocked wrong if you are using a card type sensor and it is near an intake bend.

as G Atsma said, you could just need a tune. i would verify what injectors you have as well as what type of MAF you are running.

zz4x4

Thanks all, for the replies.
Floorman, Regarding the MAP it doesn't seem to be leaking. I checked all around it with propane, soapy water, etc.
G Atsma, I might agree that a tune could be needed. Strange though since the engine internals are bone stock. The things are different are only the MAF ( different style) and the Shorty Headers. I'm told my tune is the correct 2013 tune but it was placed on a 2007 ECM which is required to run with my 2009 6l80 TCM.
S30, I'm not hearing any knock. Other than the CEL the engine is running fine. I am running the stock 12613411 injectors ( 36 lb at 58psi) . I have an electric Walbro fuel pump and WIX filter regulator. I've verified 56psi at the fuel rail and it remains steady through the RPM range.
Dread, I'm not using the card style MAF. It's the 5 wire with screen and filaments (LS1 style?) It is located around a bend from the throttle plate. I tried to lengthen the run as much as possible with the real estate I have but I would guess total run is about 8" between MAF and plate. And there is a K&N cone filter on the other side of the MAF (I know not ideal). I thought this may be causing turbulence and was contributing to the issue so I tried a long section of dryer duct connected to the MAF for testing purposes to smooth the air flow. It had no effect on the LTFT.
Che70velle, I have the OBD Fusion app and I can post the charts of the pertinent data. I need to see if I can read the retard and AFRs. Any other charts I should post?

00pooterSS

iTrader: (40)

What's your MAF reading at idle? I'd be looking for approx 7-9 gps

Check fuel pressure and volume. With the engine running push the release valve on the tester to dump fuel while running. Put the hose in a soda bottle or something to capture the fuel, it should keep running and have good flow out of the hose. If it dies or stumbles and fuel just dribbles out of the hose try another fuel pump. If this is the case you should see it go lean and feel the power get soft under WOT. But it's still an easy test to try and I highly recommend doing it.

You said it's at 56 psi on a 58 psi system. Those couple of pounds make a difference, not huge, but a difference. And when trying to stick within fuel trim limits everything counts. You can only get to 10% compensation before the light is commanded.

Check PCV. Replace just because. Sometimes they flow too much air and cause a lean code. Usually I only see that on Fords though.

To smooth airflow across the MAF use a honey comb. To find them google "MAF honeycomb". I can't post a link since it's a nonsponsor link

joecar

Check for airleaks in the exhaust (upto about 12 inches past the NBO2 sensors).

Try reclocking/rotating the MAF. As experiment, place straight tube before and after the MAF (let it hang out of the engine bay) and see what LTFT's do. Play with reclocking the MAF. Straightener screen helps, but not if tube bends nearby.

Did you correct the MAF table (specifically for this MAF sensor)...?

Are you sure there is no airleak between the MAF and the combustion chambers...? Or between CC's and 12+ inches past the front NBO2's...?

What air filter are you running...? Where is it picking up outside air from...?

PCV and AIR ports all plugged up (not leaking)...?

zz4x4

OK, here is the weekend update.

The MAF reading at idle is about .75 lb/min , the MAP is 9.45inHg and the Barometric is 29.23inHg.
Pooter, what scale are you using with the 7-9gps?
I swapped in the MAF from my GMC 5.3 and all readings are exactly the same. The LTFT is also the same as before at about 24%.
--The LTFT on my GMC is running about 11.5% at idle and there are no codes. I think the limit may be 20-25% before the code is set.--
I tried clocking the MAF and installed 2 ft of dryer duct before and after the MAF with no effect.
I posted another reply with photo of my set-up but it's stuck with the moderator so in the meantime to answer a couple questions...
I did try blanking off all ports on the intake including PCV and associated valve cover-to-Intake tube . I also blanked off the brake booster and ensured the EGR port is capped. No effect on LTFT.
Thanks all,
Jeff

joecar

Jeff,
ok, try this: add 15% to MAF table, and take another log of LTFT's (clear trims before running).

00pooterSS

iTrader: (40)

I don't tune so I don't do scaling, I do repair so all the stuff I see is mostly stock. Your baro looks right too, assuming you're around 500 ft or so elevation. If you're at higher elevation (1k feet or better) and your baro was 29.xx you should be running on the rich side.

The code setting for fuel trims gets a little tricky. It's a total FT with stft considered. Max computer compensation is 25% with some manufacturers triggering the light at 10. I'm not 100% what your exact limit is, most I work on trip the light at 10. But I work on all makes and models.

The stuff I posted would be your baseline checks. If everything checks out there move on to tune adjustments like joecar posted. However on a stock setup you should be able to get it in check without tuning.

Do you have your PCV system hooked up? If so are you running the fresh air hose for the system to the intake tube? If so make sure it's after the MAF so that the airflow through it is monitored (seen) by the MAF

zz4x4

Ok thanks pooter. Yes the MAP and Baro pressures seem correct . I'm in Dallas so about 500-700 ft above sea level.
My PCV hose does indeed come out of the intake tube between MAF and Thottle Plate so should be read by the MAF.

Joecar,
Are you saying to multiply the Airflow vs MAF Frequency line ( all values) x 1.15?

Thanks,
Jeff

00pooterSS

iTrader: (40)

The only other things I can think of from over here is try intake gaskets and before you do that, if you have the capability go in and reset the flex fuel adaptive.

I've had a couple of e85 compatible vehicles come in that don't have an actual fuel composition sensor get kinda screwy from the assumed alcohol content being off. But that usually creates a rich condition because it will think there is ethanol in the tank and it will add fuel for ethanol when there is only gas in there.

joecar

BTW: it will be easier to digest if you use Metric (g/s, kPa)... $0.02

Yes, correct.

00pooterSS

iTrader: (40)

My brain and this thread aren't mixing today. I went to lunch and came back and realized I had my head in my *** this morning. I need to correct what I wrote earlier.

When I originally wrote you should have approx 7-9 GPS across the MAF. The grams per second part was correct, except it may be as low as 6 or so at hot idle (around 550-600 rpm). I wrote later that it should be INHG, that was NOT correct. We started talking baro and with that in there I fubar'd it all together.

I don't know what you're using to read data, if you can read the MAF in grams per second I would.

zz4x4

Ok, no problem. I'll start reporting in metric . The MAF reading is about 5.7-6.0 g / s at hot idle.

dw456post

If you changed or moved the MAF sensor from the stock Chevy setup, it needs to be "retuned", and depending on where you put it in the airstream, it may need to be moved. Your MAP sensor in Dallas should read about 100kpa at key on, engine off.

00pooterSS

iTrader: (40)

At what rpm?

That should be down at 500-600 ish with a/c etc off. I'd have to hook up to a similar vehicle to give you an exact number.

Also a mechanics trick is to unplug the MAF or the MAP and if the fuel trims get better that tells you where to look. I don't do that anymore so I'm not sure if yours will run with one of them disconnected, some cars will some won't. I haven't used that method in many years since I'm more familiar with data and what to look for but I used to do it many years back.

zz4x4

The RPM is right at 592 for a reading of 5.9 g/s