kevin.m

Long story short, I'm buying a truck from my sister in law-- She is selling it to me fairly cheap because it has issues. She never committed to taking it to a shop because she was wanting another vehicle and this was a perfect excuse for her to get a new truck. I will be receiving the truck next week. I'm hoping someone else can point me to a starting point or has had the exact same issues and can guide me into what I need to replace.

Its a 2007 Ford F150 XLT Crew Cab with the 5.4l and 175ish,000 miles.

She explains it as the engine is shaking (due to skipping and misfiring from what I've seen) and wont idle. She says if you pat the gas it will idle and after warming up it will idle on its own, but still rough.
I had her take it to a parts store and run a diagnostic test, and it has the following codes:

P0316 - Misfire detected on startup (first 1000 revolutions).
P0172 System Too Rich (Bank 1)
P0300 Random Misfire Detected
P0301 Cylinder 1 Misfire Detected
And she says there were other cylinder misfiring as well, but the pictures she sent cutoff the rest of the specific cylinders.

As of right now, I'm thinking something with the fuel? Like maybe injectors? It seems with it being multiple cylinder misfires that it wouldn't be a plug or something like that? I've did a lot of searching in the forums and I've seen several different scenarios and fixes, but none that were exactly what is going on with this truck. The closest thread I found that matches my issues, it ended up being 1 fuel injector after he replaced pretty much everything.

I'm thinking when I get the truck, I may need to just go ahead and replace plugs, coil packs, and injectors. But I know that's going to cost, So I'm hoping someone can tell me an easier way. I've also read about issues with this year/engine having issues with timing? If that's it, what kindve damage am I looking at for repairs there and what would be an indicator that's what is wrong?

Thanks in advance, Hopefully I've provided enough information to give a decent idea of what is going on.

kevin.m

Any help at all would be appreciated guys and gals.

I talked with her earlier and she stated that all of this happend while driving. In other words, it was running fine according to her and then all of a sudden it was skipping so bad it wouldnt hold idle. A FB group advised me its probably not the timing because it was missing a few codes that wouldve been thrown if it was...

So far I'm waiting to get the truck by Saturday. I've ordered a MAF Sensor, Coil packs, and Spark plugs. Someone mentioned on the FB Group that it could possibly be something with an EGR?

doyall

I can't help but think that with the plethora of symptoms/codes as you present, a comprehensive and useful diagnosis over the internet is next to impossible.

Having said that, I feel your pain. A prior 5.4L of mine had similar intermittent issues that I attributed to the electronics getting wonky with age (2000 model). I was never able to conclusively track anything down and didn't feel like spending as much as the truck was worth to have everything it could be replaced.

Good luck.