When I'm accelerating, either getting up to highway speed or more throttle for hills, the engine is hesitating/cutting out. Almost like not all the cylinders are firing. At idle or cruising at a steady speed it seems fine.
Its a '00 with 115k I just bought so I don't know its history, guy who sold it SAID it had a tune up at 100k miles. Who knows?? I do know it was almost dead empty of fuel when I bought it, maybe trash in the fuel lines??? When I test drove it it ran great, 200 miles and a tank of gas later it acts up.

 

Any codes? Probably not a fix, but fuel filter? How about trying a can of sea foam in the tank?

 

Agreed. Check for codes first. Fuel filter likely. How clean is your MAF sensor?

 

The check engine light came on once, for about 10 minutes. Stopped to run in the store and it never came back on. Haven't got a code. Forgot that it had even came on till you said something.

 

MIL won't always show that there is a code.

https://www.ford-trucks.com/forums/5...t-come-on.html

 

MAF sensor? I'll admit I'm ignorant, where's it at?

 

https://www.ford-trucks.com/forums/5...ml#post8490555

 

MAF, does the truck have an oily K&N filter on it by chance?

 

Why yes, yes it does!!! At least a K&N sticker. I haven't cracked it open yet.

 

Thanks, I'll check it out!!

 

Same crap always happens to me, trying to fix something on a saturday night or weekend when stuff is closed. I would grab a can of sea foam at the gas station and put that in, ditch the K&N, put in a regular one for now, clean the MAF. Put a scan on it if you can. Easy things to do for now just to see if they help. Next would be fuel filter just because of the mileage.

 

Thanks for the advice!!! First thing tomorrow I'll check out the filter and MAF sensor. The link about cleaning the MAF mentioned MAF cleaner. Is that readily available?? Haven't looked for it but never noticed it on the auto parts store shelves either. Can something else be used?

 

Brake cleaner has been known to work also in a pinch, but I think that the MAF might leave less particulates on the sensor which is VERY sensitive and costly.

 

Brake cleaner I got.

 

Ok, got to look at my air filter and MAF today.
First the air filter: yep, it was a K&N! A filthy K&N filter! Black, covered in bugs and what looks like axle grease. It got trashed for a cheap Fram, for know any ways.
Next the MAF: it appeared to look fine. Put a few shots of Gum-out brake cleaner to it, still had a brownish,oxidized tint to it. Thought about trying some Carb cleaner on it but figure I better not risk it.
Afterwards it ran like a completely different truck. The hesitation was gone, it ran quieter and had better highway power. I bought and plan on replacing the fuel filter too. Wish I'd known you need a special tool for it while I was in town!
Thanks TrdLtly and 4mcrue for the advice!!!