Lean Fuel Trims 2004 F150 5.4L

All 2005+ Vehicles, including the 2000+ Lincoln LS, 2002+ Explorer, 2002+ Thunderbird, 2004+ F150, 2011+ Mustang 5.0L Coyote

Lean Fuel Trims 2004 F150 5.4L

Unread postby brade » Mon Apr 01, 2019 6:50 pm

I came across a good deal on a 5.4 3v truck. Guy said it had a bad engine, but it just had timing issues. Being I work as a tech at a Ford dealer, I bought the truck and fixed it. Decided I would do a VCT delete while fixing the timing. My problem is excessive fuel trim correction at mid to high loads, specifically accelerating or cruising in OD. LTFT for both banks for 20%+, but at IDLE or low speed cruise they are normal at 3%. Ive replaced the fuel pump driver module, fuel filter, cleaning the MAF, looking for any vacuum leaks, or any bypassing of the MAF sensor. No misfires present, I've replaced several plugs and coils. No exhaust leaks present that I can hear. In my experience vacuum leaks cause positive fuel trims at idle not under higher load.


I didn't change anything in the fuel tables in my tune. I changed some torque management, pedal command, but mostly wiped out the VCT. I'm using HPTuners. I have no clue how it performed before the vct lockouts were installed. Is there a table I am missing since VCT is disabled like some sort of airflow modifier. I could adjust the MAF transfer to correct fuel trims but I figured the stock calibration would be closer than that? I suppose it could just be a worn out MAF. Just looking for your thoughts.
brade
Power Poster
 
Posts: 104
Joined: Mon Dec 12, 2016 10:21 pm
Name: Brad Earlywine
Vehicle Information: 1999 Ford Mustang GT, JKU3 Cali car.

Re: Lean Fuel Trims 2004 F150 5.4L

Unread postby brade » Mon Apr 01, 2019 7:44 pm

For what its worth, stock maf table on an 06 is almost exactly 5% higher on the whole transfer. Just thought that is odd.
brade
Power Poster
 
Posts: 104
Joined: Mon Dec 12, 2016 10:21 pm
Name: Brad Earlywine
Vehicle Information: 1999 Ford Mustang GT, JKU3 Cali car.

Re: Lean Fuel Trims 2004 F150 5.4L

Unread postby decipha » Mon Apr 01, 2019 11:30 pm

I never understood why people do vct deletes, why not just fix it?

it sounds like your fuel pump is weak
User avatar
decipha
Tooner
 
Posts: 17001
Joined: Mon Jul 15, 2013 5:29 pm
Location: New Orleans, LA
Name: Michael Ponthieux
Vehicle Information: Supercoupin' x10
90 (4x 5spds) - Dante, Ruby, Daja, Ava
91 4r70w - Skarlett
92 (2x) 5spd & auto - Bianqa, Andrea
93 auto - Danika
94 5spd Rionda
95 auto Aisha
Vehicle 2 Information: Others:
00 Lincoln LS - Luanda
98 Camaro SS - Bounquisha
02 Harley F-150 - Sasasha
03 Marauder - DyShyKy
00 Explorer 5L - Bernyce
07 GMC 2500HD 6L - Veranafer

Re: Lean Fuel Trims 2004 F150 5.4L

Unread postby brade » Tue Apr 02, 2019 10:13 am

Fix the VCTs? Nah. That just asking for trouble on my particular engine with 225K miles. I use to do these repairs a bunch at the dealer. Hundreds of these trucks over the years. On customer vehicles, we keep the VCT intact due to emission laws. My particular problem was (like all of them) low oil pressure hot near idle, inability to hold the phasers, and slapping chains led to broken guides. I knew with as many miles as it had, that I could replace all the components keeping the VCT intact and still have less than 24psi on hot idle. IDK, its a crap shoot usually. Its happened many times before on worst case customer vehicles, usually to the point that most dealers just recommend a long block these days before timing repair on the 5.4L 3v. I got the truck cheap, already had the HPTuners, lockouts were about $20. Because its a DEPS system power and fuel mileage only slightly being effected, at least to my situations and purposes for this truck. I'd never recommend removing VCT on a DIPS setup like the 5.0L or most of the engines Ford makes now.

Anyway, about the fuel pump. Im maintaining 40psi at the rail with a pump duty cycle of about 28-30% at WOT as monitored with IDS.
brade
Power Poster
 
Posts: 104
Joined: Mon Dec 12, 2016 10:21 pm
Name: Brad Earlywine
Vehicle Information: 1999 Ford Mustang GT, JKU3 Cali car.

Re: Lean Fuel Trims 2004 F150 5.4L

Unread postby decipha » Wed Apr 03, 2019 12:03 am

I've fixed countless phasers as well and as long as u put a spacer in the oil pump bypass and run a motorcraft filter with 5w20 youll never have a problem with it. I've probably done over 50 of them and never once had another phaser issue nor have i ever heard of a repeat phaser issue when fixed and maintained properly.

well shit its got to be dirty injectors then
User avatar
decipha
Tooner
 
Posts: 17001
Joined: Mon Jul 15, 2013 5:29 pm
Location: New Orleans, LA
Name: Michael Ponthieux
Vehicle Information: Supercoupin' x10
90 (4x 5spds) - Dante, Ruby, Daja, Ava
91 4r70w - Skarlett
92 (2x) 5spd & auto - Bianqa, Andrea
93 auto - Danika
94 5spd Rionda
95 auto Aisha
Vehicle 2 Information: Others:
00 Lincoln LS - Luanda
98 Camaro SS - Bounquisha
02 Harley F-150 - Sasasha
03 Marauder - DyShyKy
00 Explorer 5L - Bernyce
07 GMC 2500HD 6L - Veranafer


Return to CAN Tuning

Who is online

Users browsing this forum: No registered users and 1 guest