I have a 2005 f150 5.4 with 70k miles

The CEL is flashing, it had codes of p0171 and p0301.

The engine stutters and shakes around 1/4 throttle or when cruising down the highway, but under wot it runs fine.

Normally I wouldn't drive it but I commute 100 miles a day and there are no feasible alternatives (i'm not riding a motorcycle and my other car's fuel pump is bad not to mention it has no title)

I do real good with 2 stroke engines and things without electronics but have no idea where to start. I can't change the spark plugs because I don't know where to buy the tool in town.

Thanks for any help

 

Most likely #1 coil. Could be a plug or the fuel pump since #1 is furthest from. A quick fuel pressure test can determine, but like I said, it's most likely the coil.

 

How many lbs of fuel pressure should I be seeing? And how can I test the poil pack?

 

Yea, no poil packs on that model. You have coils. Swap #1 coil with #5. See if the misfire follows.

You should be around 32 lbs at the rail.

 

Thanks for the response.
I just purchased a new coil pack. No more flashing cel, however there is still shudder at 60 70 mph. I have about 40 miles on it with no flashing. Although over 50% throttle its running fine. idles a lil better. Tomorrow I'll do a fuel pressure test.
Where's the best place to tap into the line at?
Would it make sense that maybe my plug is fouled now, if the coil pack was the culprit?

 

Also is there a high and low injector on each cylinder? Since it runs fine over 50% throttle. I've got a conquest that had a bad low injector, but its got a tb.

edit:
So now I'm thinking that it may be the fuel injector problem that I've been reading about on the forum, it does seem like there is white smoke but it's so cold outside I can't really tell.

 

It was the fuel injector, it had failed in the closed position, in case anyone else has this problem later.