Fastcar302

So, I have a 2004 F150 5.4L with 167,000 miles that has a bogging issue. Here is some background on this truck. I bought it a year ago with 155,000 miles and it had the typical ticking and diesel sound from bad cam phasers and a slapping cam chain at start up, which I have just fixed. More on that in a minute. the only aftermarket thing that has been done to it that I know of is an Airaid intake has been installed.

Since I've owned the truck it's always had an intermittent bog. The bogging would happen at partial throttle under light acceleration (approx 10mph & up) at around 1800 RPM and on the highway at steady throttle. During the bog, it emitted a loud, deep humming/droning type of sound and had a loss of power. With a little more gas, the noise would completely go away and power was restored instantly like flipping a lightswitch.

Recently, the bogging became much worse suddenly...to the point the truck was barely driveable. It gave me code P0012 - "A" camshaft position timing over-retarded bank 1. I replaced the VCT solenoids and the bogging improved from severe back to intermittently like it was before. About a month later, it started idling very low and it would die. I attributed this to the bad cam phasers and slacked cam chain, so I replaced the timing set, and installed Livernois lockouts in the cam phasers. I also cleaned the MAF, changed the spark plugs, and installed all new coils.

After all the work I've done, here's where I'm at with the symptoms. The truck starts and idles fine, but if I rev it up it will want to either idle very low when it comes back down or it will die. The idling problem gets worse as the operating temperature increases. I tried to drive the truck and when I did it would drive ok except for when I came to a stop and want to die and at full throttle from a stop it would bog very bad and barely get out of it's own way. It does NOT misfire, just bogs. There are now codes being thrown currently.

So, to recap, here's what I've done to the truck:
-Replace VCT solenoids
-Replace spark plugs
-Replace coils (all 8)
-Installed cam phaser lockouts
-Installed new timing set(chains, adjusters, and guides)
-Truck has an Airaid intake
-Cleaned MAF
-Changed fuel filter

Here's my thoughts on what could be going on:
-CMCV issues
-Fuel flow problems(lean condition - i.e. bad fuel pump, bad FPDM, bad FRPS)
-Bad catalytic converter(I doubt this one since the bog changes like a switch)
-Possible vacuum leak(Anyone know what the vacuum reading should be at sea level?)

I could sit here and throw parts at this thing and eventually fix it myself, but I figure why not use the resources at my disposal and maybe get out of this the easy way. Hopefully there is a good, experiences Ford tech or owner that has seen this problem and knows exactly what to look for. It would sure save me a lot of headache and I would REALLY appreciate some good insight.

Thanks,
Andrew

Hooah.soldier

Check the Fuel Pump Drive Module. That is most likely the issue. It typically goes out between 130-160,000 miles. It is ma detached of aluminum and is mounted to the steel frame. So over time it will ionize.

Hooah.soldier

Btw, let me know about the phaser lockouts. I am looking into getting them.

Fastcar302

Thanks for the suggestion. Is there a way to check the function of the FPDM or is it just a visual inspection to see if it's corroded? I have a scan tool that reads live data. Is there something I should be looking for on any of those readings that could help identify if this module is working properly?

Hooah.soldier

Visual inspection. It is most likely cracked and ionized. Look it up.

jdinner

Inside the catalytic converter you have two sections of material. These forward sections will break up and clog the rear sections. With the correct conditions these chunks will blow to the side and allow proper performance.
It is an easy test to loosen off the exhaust pipes at the manifolds and give it a test drive.

f150madman

Check the cats. Mine burned (?) out a few few years ago and the first symptom was dying at stoplights/signs.

Mod (Ret.)

The FPDM gets blamed for a lot, and in the salt belt roads of up north, its always good to check it. In this case however, the truck starts and runs (albeit poorly), so I'd err to the good that the FPDM is working. It simply turns on/turns off power to the fuel pump in the gas tank, by command of the ECU/PCM.


It could be an issue, but don't run out and buy one yet until you at least physically inspect its back housing for corrosion.

Millinex

What oil are you running? Mine started doing a horrible low idle (300-400 rmp) after it had gas/was in gear/warmed up and I swapped to 15W-40 and she runs perfectly now.

Summers22

iTrader: (2)

Ever think of changing the fuel filter?