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.
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.
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.
Do you have one of your old 02's to swap back in to test?
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.
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.
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 (https://www.ecoboostperformanceforum.com/index.php/board,14.0.html)
Ya sometimes aftermarket o2s do not provide proper voltages, even on Fords.
They are Bosch sensors, which are what the OE sensors are.
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://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 (https://www.oemfordpartsjackyjones.com/auto-parts/2012/ford/f-150/fx4-trim/3-5l-v6-gas-engine/emission-system-cat/emission-components-scat)
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://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 (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.
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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.
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.
I read through and forgive me if I missed it but does the stick tune exhibit this as well?
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?
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attach the XLS/CSV files directly to your post. you do have to do a preview to get to the full version of the post box which gives you various formatting/attachment options.
You mentioned vacuum leaks causing fuel trims to be off...that's not really true in this case because your air is metered at the manifold rather than pre in the case of a maf fueled engine
If you have an exhaust leak causing the issue it would have to be between the head and primary 02 sensor
I think the fuel scaling in the tune is wrong for the E0 fuel you are using...you are over fuel by at least 4% by using E0 fuel with stock parameters in the tune but that's not accounting for the 15% error you have now
But the stock fuel tuning isn't that great always in the ecoboost...and you have made changes to the volumetric efficiency by doing headwork and cat work so that can be a factor as well
You may not have anything wrong at all besides fuel tuning
Quote from: AJP turbo on November 13, 2018, 06:22:39 PM
You mentioned vacuum leaks causing fuel trims to be off...that's not really true in this case because your air is metered at the manifold rather than pre in the case of a maf fueled engine
If you have an exhaust leak causing the issue it would have to be between the head and primary 02 sensor
I think the fuel scaling in the tune is wrong for the E0 fuel you are using...you are over fuel by at least 4% by using E0 fuel with stock parameters in the tune but that's not accounting for the 15% error you have now
But the stock fuel tuning isn't that great always in the ecoboost...and you have made changes to the volumetric efficiency by doing headwork and cat work so that can be a factor as well
You may not have anything wrong at all besides fuel tuning
Thank you, I will do my best to work with the information you've given me, I appreciate it. I've had a warped manifold on this truck before, so I know what an exhaust leak is like. It got new manifolds and hardware, and I torqued every fastener on the motor to spec, also it shows no signs of having any exhaust leaks at all. Both banks would have to be leaking as well which is even more out of the realm of possibility.
Did you get the stock manifolds or the aftermarket "solid core" ones?
Quote from: SHOdded on November 13, 2018, 07:53:03 PM
Did you get the stock manifolds or the aftermarket "solid core" ones?
Stock manifolds.
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My tuner messaged me the other day stating another 3.5 EcoBoost he's tuning (head games ported heads, twin EFR's) does not have the same negative trim issues as my truck, and his port work and mod list is far more aggressive. I considered the fact that perhaps I'm getting lower than optimal fuel pressure at cruise and idle (where the LTFT's go the most negative) causing poor atomization, but the DI pump and injectors are brand new, and the truck exhibits no signs of drivability issues other than poor highway fuel economy. I also double checked that rockauto sent me the right O² sensors and they are...17323 and 17321 respectively.
I smoke checked the intake as well. Found a crack in my intercooler and patched it - however it didn't make any difference in my LTFT values once it was repaired.
I'm open to advice, as I'm nearing the point of throwing parts at it - perhaps another set of OE injectors.
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