I have a 98 f150 with 5.4l 4x4. I am currently having erratic stumbling. Some times it does it early in the morning while idling. Other times it wont do it until I am 20 miles into my trip for work. There are days where there is no issue at all, and there are days where its just a constant pain.

I just got it out of the shop last week to get several things done to it. The list got to long for me to complete in my free time.
New plugs
Front driver axle
driver wheel hub assembly
oil cooler line
oil cooler gasket
lower ball joints
oil change
General Tune up

While it was in the shop, the shop owner said they ran it through diagnostics, after listed work was completed, with no issue. He said the only issue he had was during idle, every once in a while there would be a minor hiccup that didn't register, he could just hear it. He couldn't replicate the issue that was present when I drove it up there initially.

Once I got it out of the shop, I drove it straight to the petrol station, filled it up, and everything was perfect. I drove around running errands. for about 3 hours of running around, I start to head to work. About halfway to work, it started to fall on its nose again.

Exact symptoms:
while driving-will stutter, sometimes stutter will stop with heavy acceleration. Sometimes not. Loss of power, just feels bogged down. When acting up, has trouble getting to highway speeds. Sometimes when I ease off the throttle, it will smooth out. It will run fine for a little bit, then the hiccups start. Maybe misfiring, not real sure. I am at best a shade tree mechanic, and may not be describing well enough. I apologize.

Recent history of repairs.
1 1/2 years ago, it sat for about 2 months because the sending unit quit working all together. (didn't really have the time or the money to fix immediately)
Replaced the sending unit. A day later, my son and I were headed to the lake to go fishing. I stopped by the storage unit, wouldn't start back up. It would crank, but wouldn't start. Frustrated, I called a tow truck, had it towed to the local repair shop. Ended up being the on board computer was burnt up.
But since then, the only issue I had, for almost a year, was the A/c went out.
The spitting and sputtering started in December. I quit using it as my daily driver after one day it wouldn't start, and the next day it did. It still got driven regularly, usually to town, or sons baseball practice. and on occasion my wife would drive it to work. The issue was still present, but it was never really bad. Maybe 3 or 4 times a day regardless of how much it was driven.

More recently it started to be much worse. I had tried cleaning the MAF, injector cleaner, fuel treatment, Higher octane fuel, Seafoam, Heet. all to no avail. this is over the duration of it not being my daily driver. Then I let it sit for about 6 weeks. Finally decided to take it to the repair shop because I hadn't had time to deal with the front axle, ball joints etc. Parts were just sitting in the truck.

So the issue is still present. I have read many of posts and threads on multiple forums, and google. I have ordered a replacement fuel pump, and it will arrive today. Hopeful the this fixes the issue. I realize my symptoms could be multiple things. But has anyone else had a similar issue? if so, what ended up being the issue? I love driving my truck, I cant stand the god forsaken car anymore. I want to get this resolved, and I don't really have the funds to just send it back to the repair shop for them to guess. I can guess for free.

Any advice, information, or question is welcomed.

 

Isn't there some codes to read when it sputters?

 

No. No codes are showing up.

 

Fuel filter? Plugged cats? IAC valve? Coils?

 

I have changed the fuel filter.
Not sure about the Cats. But shouldn't an issue with these throw a code? I have never had an issue with them, so I am unsure what symptoms may be had.
I have not Checked the IAC Valve. I can do that this evening. Maybe clean it. Any other suggestions on what I could do to check this? I know I can unhook it, run the engine and see how it runs. Hook it back up, and compare. Unless I am way off base.
Coils are good, from what the mechanic told me.

 

Use a Scanner to look at mode 6 data, test 53. (This is Ford's designation).
This will show the misfire counts for all 8 cylinders.
Replace the coil on any with high counts. The counts will show up in Hexadecimal notation.
These misfire counts do not set a code because the data 'history' location has no ability to do so..
Reseat the crank sensor to be sure its a solid connection.
Good luck.

 

Fuel pressure when sputtering?

 

Looks like #3 was misfiring. Replaced the coil. Boot had a small tear near the top. It has yet to sputter. True test will be on the next drive to work. Thanks for the info, and suggestions.

 

She runs Flawlessly. Thank you guys for the information and help.

 

Surprise surprise!.
Yes when you have the info, it usually works..
Good luck.