A little back round, my truck sits with just over 260K miles 2004 with the 5.4l. Lately I have been chasing a lean condition just in bank one (causing a stutter/miss). As routine maintenance my o2 sensors are recent under 100K. I also keep the MAF clean with a periodic spray of electrical cleaner. Using a blue tooth scanner, and torque app shows the sensors to be good as well. The scanner is showing me a rather constant fuel pressure reading(40psi range). When I learned about FPDM failures I isolated mine with rubber to prevent corrosion, so I do not suspect a fuel delivery issue. I have scoured around looking for a vacuum leak, and am well aware of the little bastard that pops off in the almost impossible to reach area of the intake manifold. I sprayed around with carburetor cleaner in addition to physical inspection and did not observe any leaks. Unless I'm missing something all I'm left with are the injectors, all of which are oem original. Please chime in with your advice, I'm all ears.

 

Do you regularly add a bottle of Chevron Techron or Gumout for high mileage engines to the fuel?

 

Yes I do, I try to do it prior to each oil change at 5k miles.

 

Still hoping some one has an idea I have overlooked. I pulled each plug to the injectors on bank one, which caused a rough idle, and triggered a cylinder miss fire on each. I also tested resistance, and all showed 12.9 ohms. It would seem I have ruled out a bad injector, perhaps one is clogged. I truly am not sure where to look next? The only code I have seen is the P0171, I have had no cylinder missfire codes during the hesitation Im getting going dow the road.

 

@nickbrumaghim;


You mention you have the Torque Pro App. The lean condition on Bank 1 should be accompanied (confirmed) by high fuel trims readings on that Bank 1. It's usually caused by "unmetered air" getting into the mixture after the MAF. But you mentioned checking for leaks. It COULD also be an exhaust leak at the exhaust manifold on the passenger side. The 5.4 Tritons seem to be prone to that. The V.V.T system retards the cams to breath some exhaust gases back into the cylinders (EGR effect) - and that's where/why raw Oxygen can get back into the exhaust ahead of the O2 sensor and drives it NUTS - ie: P0171. I recently saw a pretty simple clever test for exhaust manifold gasket leaks. This guy hooked a shop vac securely to the tail pipe (w/ duck tape) and used a piece of 3/4 heater hose as a stethoscope to listen all around the manifolds, headers, cats, mufflers etc listening for an air hiss or whistle - and found a small MF gasket leak near cyl #4. Lol - pretty cleaver. I subscribe to cheap diagnostics!


I had the same symptoms & code on my '04 5.4l 3v. Set up a Torque dashboard with Fuel trims & O2 graphs as shown in the photo below and the Bank 1 Fuel Trims & 02s would go NUTS when I sprayed Starting Fluid (Ether) under front passenger side of the intake manifold by the crossover. Replaced the plastic Intake Manifold and instantly cured the problem. Will never know if it was truly the IM or if it could have been the IM gasket on the inboard side of cyl #2 intake port - It looked to be leaking.


I have a feeling the miss / sputter is coming from Plugs or electrical.


Good Luck










Fuel trims after replacing Intake Manifold. O2's were only 10k miles old.

 

Thanks for the thoughts. You are correct that my fuel trims in bank1 are reading higher than in the unaffected bank2. I have kept up on my plugs, and typically a bad coil pack gives a miss fire code, so Im thinking electrical is not likely. I have heard of the shop vac method, but using it to blow, and then soapy water to find the leaks. I suppose I should absolutely rule out a hard to find leak before getting to much further.

I was trying to think outside of the box, and did learn a bank one lean does occur in variable timed cams which have skipped time. A light bulb went off, as I have never touched my cam phasers. After hearing so many people change them early on just to get the knock back, I decided to leave them alone unless it breaks.

Much time has passed, and a lot more is know than in the beginning. I cant help but consider I may have developed loose enough chains to have lost propper time. I dont know if a shop can see the parameters of this system in real time, or if physical inspection is the only determination.

 

No big reason to suspect jumped time because if chains were loose enough to jump a tooth you'd be complaining about startup chain slap or worse drivability issues than just a stutter/miss. That is too much like a spark plug breaking down or semi-fowled from running rich. REMEMBER, the ECU thinks bank one is lean - so its increasing fuel trim on Bank one to compensate - and P0171 says it can't correct it (because it has maxed out the fuel trim adjustment parameter - probably +25% or greater). It can even compensate for one badly plugged up injector - which makes them hard to diagnose, but I don't suspect yours are the problem. See https://www.f150online.com/forums/v8...ml#post5159514


You mentioned pulling the plugs on Bank 1, I'll bet the tips of plugs on that bank are black. If one was chalky white, you could have a plugged up injector, but I don't really suspect that at this point. How many miles are on the plugs & how was the plug job done. I have some far out ideas about plugs changes on these engines. See: https://www.f150online.com/forums/v8...ml#post5159499


Your fuel pressure reading is fine (around 39-40psi). You mentioned 02s were replaced, about 100,000 miles ago. I am an advocate of changing 02s preventatively at around that interval. They DO get 'lazy' and though they will read between .1v and .9v, they get out of calibration such that a .45v reading is NOT at the optimum 14.7:1 fuel/air ratio. Just a thought.


A good shop can check real time parameters of the timing system - but with the Torque Pro App, You can too if you know how to add custom PIDs and custom gauges in the App. I have done lots of digging for PIDs used on the Ford IDS (Integrated Diagnostics System). Six parameter IDs I know of that are available for the vvt system are:

1) PID# 16B1 _ bit 5 __ VCTENA - Conditions correct for Variable Valve Timing operation. ON/OFF _Equation= {A:5}
2) PID# 16CD _ 2bytes _ RCAM - Requested Cam Retard (in crankshaft degrees) ºretard _Equation= ((SIGNED(A)*256)+B)/10

3) PID# 16CF _ 2bytes _ CAMDCR Commanded Duty Cycle for VCT Solenoid (in %) _ Equation= ((A*256)+B)*(100/32767)

4) PID# 16CE _ 2bytes _ CAMERRR VCT CAM Error (in Crankshaft Degreesº) [[ plus or minus degrees that cams are OUT of sync with requested retard ]] _ Equation= ((SIGNED(A)*256))+B)/5


5) PID# 1103 _ bit 7 __ VCTFAULT Variable valve timing system Fault _ Equation= {A:7}


6) PID# 1107 _ bit 0 __ CMPFM Camshaft Position Sensor Fault _ Equation= {A:0}


These PIDs are not in the Extended set for Ford that comes with Troque Pro. They have to be added. There's a very lengthy post (but with several good screenshots) of the Torque dashboard gauges I created to monitor my variable valve timing system. http://www.ford-trucks.com/forums/11...l#post15647418 Creating a dashboard with gauges for these and other things (such as Engine Load, RPM, or Throttle Position, ect) gives some interesting insight to the vvt system.


Let us know what you find out.

 

First off thanks for thr detailed information! Im amazed at the power and functionality of the torque app. I have some learning to do.

As for my plugs, you miss read, I have not pulled and inspected since this issue arrised. I believe this set went in right around 40k miles ago. Im running motor craft. The first time I swapped them I ran aftermarket (autolite) I think, and they were done at about 90k.

As for the chains, my truck has had intermittent start up rattle for quite some time probably the last 200k miles. Im going to keep digging, Id hate to invest that amount of time and money into the truck, at this stage. It gets used hard, and has served me very well. I had tentatively planned on replacing it next year. I had just began looking at bigger diesels, until I saw they increased payload on the F150, and Im interested in the ecoboost.

 

Update no resolution unfortunately. I took the truck to a reputable independent to have a IDS scan performed. According to the results the MAF was bad. Fuel pressure was good, injectors show good flow, and balance. Their diagnostic search didn't reveal anything else, so I replaced the MAF to no avail.

In addition I picked up a set of low mileage oem coil packs and just swappwd them out, as mine had 260k, and all though my scanner didn't catch it, the IDS said I had a 1,3, and #5 miss fire. All though the truck runs better, when this happens its just the same as always.

BUMMER!

 

I had the same lean error code, but I also had a misfire code at cyl 2 P0302. I thought I had two problems. The problem was a combination of a bad coil, and a bad boot. I played with moving the coil to a good position and the trouble followed the coil. I had a spare COP from replacing the wrong #3 position COP. Instead of moving the new COP to the #2 cylinder, I put what should have been the good used #3 COP on position 2. Still had the lean code and misfire. I bought a new boot and put it on the original #2 COP, still had both codes. Then I put the new boot on the good used COP and my troubles went away. Codes have not returned in about 600 miles.

 

nickbrumgahim,


Sorry you're still having the same trouble. I re-read your OP. I swear - you have "unmetered air" getting to the upstream O2 on the passenger side. Not to beat a dead horse here, but there is not much else that give elevated STFT coupled with a P0171 (lean on bank 1). That PCM is 'lengthening' injector pulse width on bank 1 trying to compensate for the lean condition at the O2 sensor. And it's still UNSUCCESSFUL in establishing the proper air/fuel ratio. The MAF is common (equally) to both banks.

I believe the 'misfire' thing is a rabbit trail (for now). Confucius say "Chase more than one rabbit at a time, they all will get away". While a vacuum leak on one bank could cause misfires - the CLUE here is "_CAUSE_". In absence of other codes leading in that direction, (such as cam timing codes or something), I would ignore that symptom until I get fuel trims on bank 1 back to normal. Multiple misfires (1,3,5 not on same bank), IF THEY ARE THE SOURCE, will also cause the PCM to report 'over-rich' because of 'unburned fuel' getting to the O2. You have the opposite condition. Excess _air_ getting to the O2 - on bank 1 only. (Where is it coming from?).


A faulty (low flow) injector(s) can cause lean condition coupled with elevated Fuel Trims because PCM is trying to compensate. Not likely multiple ones though (1,3, & 5 - different banks). One totally plugged injector can be compensated for with fuel trims - but not without a hard miss on the affected cyl. ONE almost completely clogged injector could cause fouling and misfires on the other cylinders - but wouldn't effect cyl 5 on the OTHER bank and should exhibit itself in BOTH short term AND long term fuel trims on bank 1.


Have you ACTUALLY monitored LIVE fuel trims and O2 readings WHILE spraying a flamable spray? I like starting fluid (ether) - it's more volotile than other stuff. You can verify the systems sensitivity to the stuff by spraying a small amount into the 'intake' and observe BOTH O2's react.


ALSO, take a drive while monitoring F-trims and O2's. An intake vacuum leak will effect STFT more than LTFT at low RPM or idle (simply because the ratio of un-metered air versus metered air changes so dramatically), and at < 800 RPM the phaser's are TOTALLY deactivated by the PCM. If the leak is post combustion chamber (ie: exhause), while NO EGR effect is taking place the STFT should not be elevated due to positive exhaust back-pressure. However, while driving, (very light crusing), STFT should be 'low' or 'its lowest'. That's when fuel requirement is lowest, and the phasers reach full retard. High or elevated STFT under this condition would make me look seriously at post combustion chamber air getting into the exhaust stream ahead of the O2. It wouldn't take much to upset the lambda enough to cause ^ FT and a P0171. I THINK an exhaust leak would exhibit itself more in LTFT because this would represent a greater ratio of driving conditions (but I don't KNOW this). But you should be able to observe these subtle conditions on Torque Pro.


But, ---- JUST SAYIN'----, you've got air getting to the O2 on the passenger side from SOMEWHERE. Mine proved to be either a cracked manifold, or IM gasket - I just replaced BOTH. The damn plastic manifolds are two piece molded plastic, and I don't trust the plastic welds or glue at all the joints. I _found_ my problem by spraying starting fluid UNDER the IM at the coolant crossover on the right front. There can be NO PLAUSIBLE explanation for that action effecting O2 signals - unless some of it WAS getting into combustion process on bank 1.

 

I have personally seen an exhaust leak before the front O2 trip a lean code.

 

Same exact thing on my truck. 2004 f150 fx4 5.4. P0171 code, trucks runs like crap and feels like misfire. Replaced fuel filter, ran injector cleaner through fuel, cleaned MAF sensor, sprayed whole engine bay with brake cleaner to look for vacuum leaks, checked fuel pressure, swapped coils around, pulled plugs to look at any physical difference, no luck with anything. Ended up being #1 spark plug. It looked exactly like other plugs I pulled. Replaced and instantly ran fine.