Shuddering, Stuttering, Misfiring Issue
 

Ok, I made a previous thread where I thought my issue may have been the cam phasers but they turned out not to be the issue. The other thread is here: https://www.f150online.com/forums/20...ers-issue.html

Done several searches and made changes suggested to others but I am still stumped.

Basically have been having issues with my truck stumbling at idle and sometimes when accellerating, especially at low rpm in overdive. Definitely feels down on power, but the stuttering seems to be pretty intermittent. Worst bucking is when in overdive at cruising speeds like going up a small incline, kick it down a gear and accellerate and the shudder goes away. Runs better cold than when warm. Originally the truck bogged on accellerating out of a parking lot in mid May and the truck threw a CEL. When I had the truck scanned it threw 32 codes (a new record for the Autozone guy), almost all of them were misfire codes on the passenger side bank. Took the truck to a Ford tech buddy who replaced the VCT Solenoids for me and the truck ran great for an hour and then the stumbling/stuttering came back. Waited for it to throw another code and nothing popped up for a couple weeks, even with a 100 mile trip thrown in. Finally had the CEL come on and the code was 0316 and 0301. Made some changes and still had the problem but it wouldn't throw any codes again for weeks. When it finally did again it was the same 0316/0301. Here are the parts I have replaced:

All 8 spark plugs were replaced
VCT solenoid on both sides
COP on cyl#1
Injector on cyl#1
Fuel filter
FPDM
Cleaned the MAF
Passenger side cam sensor
Ran 2 tanks of gas with injector cleaner - no effect

Almost feels like a trans issue, but it will shake/shudder at idle with the trans in Neutral and in Park

Truck is a 2006 Lariat with the 5.4 triton motor and only has 62K miles on the odometer. Truck has a Banks intake and full Banks exhaust. I bought it last October with 56k on the odo.

Any help would be appreciated.

this may sound random, but i did alot of research on my truck which was doing the EXACT same thing. i also compared notes with other f150 owners who had the same issue. each of us found a roller rocker that has went bad. i found mine between the head wall and the valve spring. apparently the roller froze and the cam kicked it out. pull your valve covers and verify all 24 roller rockers are in place. i would almost put money on having lost one.

Thanks for the reply. I'll talk to my friend, he pulled the valve covers and checked for gauling that may have been caused by oil starvation but said it was clean. Not sure if he looked at all of the rockers or not.

Misfire
 

Don't know if this helps, but my 01 did something similar. After having new plugs installed I had a noticeable miss. Went back to my mechanic and he found one of the plug boots was cracked. Replaced both boot and coil pack, problem solved.

Thanks for the reply. One more thing to look at, though mine had the miss before we changed the plugs as well. I don't think my buddy would have missed a bad boot, but stranger things have happened.

Can't get it back to my buddy until the end of the month. He's planning to run a compression test and try to rule out something mechanical. The big fear is it's a wiring gremlin.

About ready to light this truck on fire right now.

It's good to replace boots when doing plugs. They crack from the heat. Also, is it possible you got some dilectric grease on the lower part of a plug? Sometimes happens when trying to coat the shank.

My buddy did the plugs, I can ask about that. I'll see about ordering some new boots in the meantime. Thanks for the suggestion.

Replaced all the COPs, no change. Still only getting the misfire in Cyl 1. Took it to the stealership and they had it for 2 days and said the fuel rail "popped" off while they were looking at it, and wanted ~$950 to fix the fuel rail mounting bolt because the head had apparently sheared off. Had them put the fuel rail back on and took it home.

Truck has been running worse and worse. Idle used to have a periodic miss, now it idles like it's missing multiple cylinders, and driving the same way. Getting embarrasing to sit at lights and just drive the damn thing. The loud exhaust broadcasts the issue to everyone. Still only throwing specific misfire codes for cyl 1, though I had injector codes pop the other day, (cyl 1 and cyl 3 injector open loop). Codes 0201, 0203 and the 0300 random misfire on top of the 0301 cyl 1 misfire.

Ordered and new intake (Dorman $176 on Amazon) so I don't have to worry about the passenger side fuel rail only having a single mounting point. Ordered the 16mm compression tester adapter so I can check that this week as well.

Any help would still be appreciated.

I have this problem too it drives me insane. Did you try or have any luck with this answer?

I have the same issue on my 08. Although I still haven't got a code. I did all the plugs and it went away for a while, then did the cops and it ran real good for a couple weeks. But now its back.

I didn't check for this, but my buddy who swapped out the VCT solenoids said he doubted this was the issue because the engine is so quiet. He said the rocker issues he's seen have been extremely loud and easily diagnosed. Unless someone had this problem and the truck never made a noise with the lifter being kicked out?

My 04 is doing the same thing. Would never throw a code and finally one day I didn't try to give it gas to make it stop and rode it out to a cyl 4 misfire code. Swapped my cop to cyl one and reset the code. Got it to do it again and still cyl 4 misfire. Going to do plugs and see what happens.

well, i ended up replacing the motor. it had 190k on it and i ran some seafoam through the motor because it was collecting sludge.. well it clogged the pickup screen for the oil pump and cooked the motor. i'm currently having a whole different set of issues with the new motor. i have it at a mechanic right now. i threw in the towel. lol

one thing i didn't see you talk about was the cam phasers and phaser solenoids.

i assume you got yours fixed by now. what was the solution?

Sorry for the late reply, couldn't log on for some reason.

Embarrassingly my problem turned out to be the spark plug in cyl 1. Last time I rely in something being new not being the problem.

I've learned this: new parts can go bad or be bad out of the box.