Ben Klepacki

Hey guys,
Here is the issue. I have a 2006 F150 Lariat (5.4L) which has a rather rough idle and has been intermittantly throwing misfire codes. I have had misfire codes thrown on virtually all cylinders (both banks) and a lean bank two code. Freeze frame on my code reader is showing OL Fault on fuel system 1 and CL Fault on fuel system 2. Nothing has been changed just before this started to happen. The plugs are newish and look in good condition. Fuel filter has 5000 miles on it. I have checked for vacuum leaks through a mechanics stethiscope, spraying ether and a vacuum gauge. Everything seems normal. I have also put in fuel injector cleaner and ran seafoam through (both in the tank and through the brake booster line). Anybody have any further ideas?

GATORB8

It the throttle body and MAF clean? You don't happen to have a tuner and CAI installed do you? What P codes are you pulling?

Ben Klepacki

Sorry, I should have included, I also cleaned the MAF with electrical connection cleaner. I have thrown P0174, P0308, P0307, P0304, P0303, P0302, P0301 and I am pretty sure I through a P0305 first and cleared that. P0308 and P0304 are the most common misfires. I do not have anything aftermarket done to the truck other than a K&N filter (hense the cleaning the MAF)

Ben Klepacki

Also, the misfires and rough running is intermittant. The rough idle seems to be more constant. It does seem less pronounced at heavy throttle. Finally, the fuel pump assembly was changed about a year ago for a remanufactured one due to a broken fuel level sensor.

GATORB8

Do you have access to alldata? I think starting to go through the pinpoint tests may be the best way to go from here.

Ben Klepacki

I don't have an account set up with them and I have never used them...

GATORB8

It's a good way to get access to the Ford Service Manual if you don't have one, the private site is alldatadiy.com. ~$20 a year instead of a couple hundred for the manuals.

twthomas1

I am having same problems. Mine started with a misfire under throttle to get on highway and would pop and shake, check engine light would come on and feel like the 4 wheel drive was engaged and shaking like crazy until I would feather the throttle and light would go out it would be ok until full throttle. I figured @ 96000 miles I would change plugs and what a dissastor that was with factory plugs still in it but got threw that and beings it throwed the misfire on #3 I changed the coil and nothing changed then I changed the Injector on the same cylinder no change. I swapped them on to #2 and still missfire on #3 wired. Took to the dealer and the say VCT solinoid was clogged and the cam gear needs replaced and they could not explain to me as why but to tell me it would be $2000. So i took it to another mechanic and he said it was missing on all cylinders but #7 with a slight hit and miss. I have contacted ford but they would not help and truck has been down a couple of months with payments still needing paid and out of warranty and darn sure no 2000 to have them fix. I can do the work if I new it was deffinately the cam gear and the only reason I could see it being that would be the cam phaser and that is all they had to say. I had also spent #300 on the vct soleniods and replaced them and no change. I would appreciate any views and suggestions. TYVM

Markdas

Are you still getting codes when you do run it?

It could be a timing related issue? If you have done all the easy stuff, like checking all spark plugs again, check/change the coils or at least the boots and springs.

Check all wiring connections, air filter, oil and oil filter change with 5W20 and Motorcraft Oil filter.

Once you have done all the easy things, it could be time to suspect the timing gear. Trouble here is the cam phasers only really wear out due to poor oil pressure and flow, this could be due to sludge or failed chain tensioners. Have you done a check of engine noises with a stethascope, check along each valve in turn, listening for any camshaft, lash adjuster or rocker noise. Then listen to each cam phaser location for excessive noise. These engines can be quite noisy! Listen to each injector as these are pretty ticky too!
There is a good trick that a guy on here posted up....remove the oil filler cap and use a length of hose to poke a little way in and listen through that for metalic noises.

If you do find you have any chain, phaser or lifter noise, it could be time to do the entire lot......chains, guides, tensioners, phasers, lifters and rockers.

Its a DIY job but you need to take your time and ensure the timing is correct and the chain tension is good!

Search on here for a post by S_Vares who has done a lot of this work, it includes good diagrams too!

this pic is failed tensioner seals on my truck

powerranger262

I would check out the fuel pump driver module above the spare tire for cracks. Pretty well known problem and could be an easy fix for you.