I have an 06 f 150 scab 5.4 3v. It runs fine until your on the high way and try to pass. When you give it full throttle it Boggs down and doesn't move until you let off the gas and gradually give it gas. Now I have read many things and people seem to think that it is the plugs causing this problem. If it was the plugs wouldn't it miss all the time. If it was injectors or cops wouldn't it throw a code. I have an appt with ford tomorrow to diagnose it for 50 dollars. My personal mechanic wants to do a fuel pressure test. I've only had this truck for 2 months and I'm fed up with it I just want it to be fixed without making me file bankruptcy. Also I took it to an exhaust shop because there is a tick coming from the pass side. I don't think it's the cam phaser issue I'm not sure though. They looked at it and came back said they didn't find anything I asked it they inspected the passanger side manifold they went looked at it came back 10 minutes later and said they found it and I need a new pass side manifold. I don't know what to do with this dang truck. It's also getting terrible gas mileage.

 

It makes sense that it wouldn't be the plugs because it's not throwing a code. A few more days and I'll rip all of my hair out and start talking to my invisible friend.

 

My bet is plugs/COP. The miss isn't detected until you are under a high load situation. Case in point: my 1998 5.4L would have a slight mess/hesitation when accelerating up a hill in overdrive. If I floored it, the miss would appear to "go away" because it was being covered up by shifting into a lower gear and the other 7 cylinders making up for it. The shudder would only occur under moderate acceleration in top gear. Replaced all of the COPS, instant fix.

 

how many miles on the truck?

 

63500. Ive posted this before just trying to figure it out before i change cops fuel pump plugs and injectors.

 

When is the last time you replaced the fuel filter?

 

Last week i also cleaned and reoiled the air filter also cleaned the throttle body

 

Cleaned the maf too

 

I have the same issue as you. When you try and pass someone in my 04 5.4L 3V, the engine has a really hard time if you put the gas pedal to the floor, when you let off and it shifts in to another gear, it does a little better.

City driving is ok, but if i needed to pass someone on a 2 lane road, I have to floor it way behind the other vehicle just to get enough speed/power to get past the other vehicle...really becoming a safety hazard too. If i had to suddenly get out of the way of something, I wouldnt have enough power if i floored it to get out of that situtation.

I have replaced the plugs with motorcraft plugs, new air filter, new fuel filter, new fpdm, new cam phasers, new timing chains, new tensioners, ran injector cleaner through, cleaned maf and tb, made sure the 4x4 was not turning the front half shafts (had to replace both IWE's and all the vac lines).

Still having the same issue, i have sunk so much money in to this truck its not even funny, saved some money by doing it my self but its really starting to irritate me with this power issue in the upper RPM's.

I have no check engnie light, my buddy with a snap-on scan tool tried to pull codes but none showed up. I don't want to keep buying parts if its not going to fix it.

I dont know if COP would help? Also im investigating the CMCV system on the intake. If i could get some clarification on how they actually work and when they are supposed to be moving it would really help me. Dont really want to dismantle the lower intake if i dont have to.

 

Oh man reading your post gives me heart aches. I know and feel your pain. I was in this same spot last summer. Sank in so much money trying to get my truck running right, but after each fix another issue popped up. Loved my truck, babied it with much care but the 5.3 3V was so problematic. I attributed it to being the first year of the new motor and body but the more I see on the forums, it seems like a large % of people have probs with the 3V.

Not sure this will help you but after I got my trans fluid flushed, seemed the acceleration issues improved for me on the old truck I had.

Bump, I hope someone here can help you guys with a solution.

 

The CMCV is part of the intake, the only serviceable part is the actuator on the back of the manifold. the opening of the CMCV plates depend on many factors, including throttle position/load/rpm, Ive been told they are also a progressive opening depending on said conditions they are fully open any between 1500-3500 rpm.

 

Relentless85, take it to a muffler shop and get the cats tested for blockage.

 

How much would that cost and If the cats are restricted, won't that be a huge cost to replace them? Doesn't the 04-05 F150's have 4 cats?

I looked on rockauto for cats and they are 250+ a piece

 

you can get magnaflow cats for $60. you would only need 2 of them anyway and you can sell your stock cats to a scrap yard for over $80 each!

 

$80! Wow, no wonder all the meth heads around hear steal cats off trucks and suv.