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Odd negative LTFT values - 2012 F-150 EB

Started by jibtechwarrior, November 11, 2018, 11:27:59 AM

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jibtechwarrior

Hi guys, I figured I'd try this forum out as there are probably more people familiar with logging than the other F-150 forums I'm on.

I've been chasing this issue long enough to enlist some more brains on the issue. Since installing my new shortblock, my tuner and I have been chasing the cause of my truck pulling fuel pretty much constantly. LTFT's are .85 and .89 for bank 1 and 2 respectively. The truck has catless downpipes, an AFE intake, pocket ported heads for performance mods. It also got new OEM injectors and SP534's, and I just put in new Bosch primary O2's. It runs great - no issues there, however we're concerned as to why it's pulling fuel all the time with my minimal mods.

For those familiar - negative LTFT's are kind of odd as there are fewer variables that would cause a vehicle to pull fuel than there are for one to add (eg. vacuum leak) There are no exhaust leaks, but the downpipes are stock with the cats cut out professionally.

If anyone has logs of their stockish trucks laying around they'd care to glaze over or share, I'd appreciate it very much. I also have tons of logs under various conditions if anyone would like to take a look as well.

Thanks in advance for your feedback.
2012 EB F-150. Forged shortblock, pocket ported heads, catless downpipes, intake and a really good tune.

FoMoCoSHO

#1
Did you reset your KAM after the swap?

IDK about the F-150 but LTFT on all 3 transverse I've owned were at about +4-7% with the oem calibration IIRC.


jibtechwarrior

Quote from: FoMoCoSHO on November 11, 2018, 12:09:47 PM
Did you reset your KAM after the swap?

IDK about the F-150 but LTFT on all 3 transverse I've owned were at about +4-7% with the oem calibration IIRC.

Thanks for the reply buddy.

Yes, through going through many tune revisions etc and having the battery out, the KAM has been reset a few times at least. I know, my numbers are huge negative for a vehicle on pump gas and minimal mods which is why it's frustrating not being able to find the root of the issue. I put in brand new OEM injectors as well.
2012 EB F-150. Forged shortblock, pocket ported heads, catless downpipes, intake and a really good tune.

FoMoCoSHO

Do you have one of your old 02's to swap back in to test?


FoMoCoSHO

Did your tuner mess with stoich in the tune?

IIRC oem uses 14.1 for E10, if he changed it to 14.7 that could explain it.


jibtechwarrior

Quote from: FoMoCoSHO on November 11, 2018, 12:25:22 PM
Did your tuner mess with stoich in the tune?

IIRC oem uses 14.1 for E10, if he changed it to 14.7 that could explain it.

I cut the connectors off the O2's to get the box end of my wrench on them, so they are no longer usable. I swapped new ones in to see if it would help with my issue. I'm running Shell 91 in Canada, which doesn't contain any ethanol. So 14.64:1 for me still.
2012 EB F-150. Forged shortblock, pocket ported heads, catless downpipes, intake and a really good tune.

ZSHO

#6
Welcome aboard! I would of went with the stock Motorcraft 02 sensors especially with the Front wide-band sensors since they play such an important role with your AFR!

Due setup an Intro @ your earliest convenience, thanks.  Z

https://www.ecoboostperformanceforum.com/index.php/board,14.0.html


2013 Performance Package SHO| Livernois Custom Methanol Tune|3-Bar Map|Reische-170-Stat|Full Race Tial-10psi BOV in Black|PPE-Gloss Black Hot Pipes|EPP Dual Intake in Gloss Black|PPE Catted DP|Corsa Sport Cat Back Exhaust|H&R Sport-Springs|CFM Performance Billet Valve Cover Breather In Gloss Black|Llumar 20%Ceramic window Tint|MSD Ignition Coils in Black|Extreme Roof Spoiler|Redline Fluids all around|Gearhead Intercooler|First-SHO With Direct Port Alky-VP-M1-100%-Methanol Injection|LMS-Custom-Dyno-Tuned @ 415whp-465wtq| Best Trap Speed of 115.54 mph|

SHOdded

Ya sometimes aftermarket o2s do not provide proper voltages, even on Fords.
2007 Ford Edge SEL, Powerstop F/R Brake Kit, TXT LED 6000K Lo & Hi Beams, W16W LED Reverse Bulbs, 3BSpec 2.5w Map Lights, 5W Cree rear dome lights, 5W Cree cargo light, DTBL LED Taillights

If tuned:  Take note of the strategy code as you return to stock (including 3 bar MAP to 2 bar MAP) -> take car in & get it serviced -> check strategy code when you get car back -> have tuner update your tune if the strategy code has changed -> reload tune -> ENJOY!

jibtechwarrior

#8
They are Bosch sensors, which are what the OE sensors are.
2012 EB F-150. Forged shortblock, pocket ported heads, catless downpipes, intake and a really good tune.

ZSHO

#9
I'm seeing Motorcraft Heated 02 sensors specifically tailored to your vehicle!

8F9Z-9F472-G   Oxygen Sensor
F150; 3.5L; FRONT; LEFT


8F9Z-9F472-H   Oxygen Sensor
F150; 3.5L; FRONT; RIGHT

I would also check the PCV System for leaks! Best of luck. Z


https://parts.levittownfordparts.com/auto-parts/2012/ford/f-150/fx4-trim/3-5l-v6-gas-engine/emission-system-cat/emission-system-scat

https://www.oemfordpartsjackyjones.com/auto-parts/2012/ford/f-150/fx4-trim/3-5l-v6-gas-engine/emission-system-cat/emission-components-scat


2013 Performance Package SHO| Livernois Custom Methanol Tune|3-Bar Map|Reische-170-Stat|Full Race Tial-10psi BOV in Black|PPE-Gloss Black Hot Pipes|EPP Dual Intake in Gloss Black|PPE Catted DP|Corsa Sport Cat Back Exhaust|H&R Sport-Springs|CFM Performance Billet Valve Cover Breather In Gloss Black|Llumar 20%Ceramic window Tint|MSD Ignition Coils in Black|Extreme Roof Spoiler|Redline Fluids all around|Gearhead Intercooler|First-SHO With Direct Port Alky-VP-M1-100%-Methanol Injection|LMS-Custom-Dyno-Tuned @ 415whp-465wtq| Best Trap Speed of 115.54 mph|

jibtechwarrior

Quote from: ZSHO on November 11, 2018, 05:38:46 PM
I'm seeing Motorcraft Heated 02 sensors specifically tailored to your vehicle!

8F9Z-9F472-GOxygen Sensor
F150; 3.5L; FRONT; LEFT


8F9Z-9F472-HOxygen Sensor
F150; 3.5L; FRONT; RIGHT

I would also check the PCV System for leaks! Best of luck. Z


https://parts.levittownfordparts.com/auto-parts/2012/ford/f-150/fx4-trim/3-5l-v6-gas-engine/emission-system-cat/emission-system-scat

https://www.oemfordpartsjackyjones.com/auto-parts/2012/ford/f-150/fx4-trim/3-5l-v6-gas-engine/emission-system-cat/emission-components-scat
Thank you sir. The Bosch sensors I ordered off rockauto are stated to be OEM, they are also what my engine builder recommended and they look identical to the OEM ones I removed, down to the blue jacket. So I do believe they are truly OEM sensors. A leaky PCV system would more than likely cause my trims to be in the positive I would think, though.

I appreciate the ideas, thanks you guys.

Sent from my SM-G930W8 using Tapatalk

2012 EB F-150. Forged shortblock, pocket ported heads, catless downpipes, intake and a really good tune.

SHOdded

I would check turbo piping and the intercooler for pooling oil/crud anyway.  Normally, yeah PCV can cause higher fuel trims, but if you have enough fumes in the PCV stream, you may actually be depressing those trims.  Seeing as this is a new shortblock and is in the breakin period (?), it is possible.  We have heard of PCV issues time and again on the F150, and also intercooler issues.  Might go away on its own as the block wears in, might not.
2007 Ford Edge SEL, Powerstop F/R Brake Kit, TXT LED 6000K Lo & Hi Beams, W16W LED Reverse Bulbs, 3BSpec 2.5w Map Lights, 5W Cree rear dome lights, 5W Cree cargo light, DTBL LED Taillights

If tuned:  Take note of the strategy code as you return to stock (including 3 bar MAP to 2 bar MAP) -> take car in & get it serviced -> check strategy code when you get car back -> have tuner update your tune if the strategy code has changed -> reload tune -> ENJOY!

jibtechwarrior

Quote from: SHOdded on November 12, 2018, 06:18:59 AM
I would check turbo piping and the intercooler for pooling oil/crud anyway.  Normally, yeah PCV can cause higher fuel trims, but if you have enough fumes in the PCV stream, you may actually be depressing those trims.  Seeing as this is a new shortblock and is in the breakin period (?), it is possible.  We have heard of PCV issues time and again on the F150, and also intercooler issues.  Might go away on its own as the block wears in, might not.

I actually thought about that, possibly fuel diluted oil (from DI) vapors altering the trims, or even a faulty purge valve feeding fuel vapor into the motor...I'm done breaking it in now, and there's nothing to show me it has excessive blowby. Yes the PCV connections are cruddy like usual, but nothing out of the ordinary.
2012 EB F-150. Forged shortblock, pocket ported heads, catless downpipes, intake and a really good tune.

AJP turbo

I read through and forgive me if I missed it but does the stick tune exhibit this as well?
SCT Dealer/Custom Calibrator                        
Specializing in 3.5 Ecoboost   
Remote/email custom tuning including E85 blends 
Authorized retailer for all SCT devices. 
 
Former:2014 PP SHO
3 bar 93 tune, Airaid, Stainless Works non catted DP's  
405whp/520tq
Dyno
     
Current:2016 F150 2.7 Ecoboost
Tuning in progress

jibtechwarrior

Quote from: AJP turbo on November 13, 2018, 04:41:10 PM
I read through and forgive me if I missed it but does the stick tune exhibit this as well?
Yes. I'm unfamiliar with posting logs directly to the forum, how does a guy do that?

Sent from my SM-G930W8 using Tapatalk

2012 EB F-150. Forged shortblock, pocket ported heads, catless downpipes, intake and a really good tune.