Hello all.
I maybe jumping on this a little pre-maturely, but just in case I wanted to get some idea's.

Yesterday while driving my truck I noticed that I'm getting a hesitation while on the accelerator. By that I mean when I'm on the gas pedal lightly I can feel the engine doing like a sputtering/hesitation/jerking like it's starving for gas.

I've only noticed this between like 40-55mph, by time I hit 60 it goes away, or under 40 I don't notice either. At idle there is nothing wrong at all, and it start's up great.

I usually put mid-grade gas in my truck (89 octane), but last time I put gas in I put 87 in by accident, and then my buddy who was borrowing the truck filled the tank with 87 too. So at this point I'm thinking that maybe it's just the gas gunking up the injectors or something. This is not my dd either, but tomorrow I'm going to try to get some gas used up and put high octane in to see if it will smooth things out.

Anyone have the same deal before, or have any suggestions? I have been doing some searching around too but have not found much on this problem. Thanks ahead of time!

 

Could be a number of things...could be the things you even mentioned. Since you put GAS in it I'll assume it's a V8 or V10. Have you changed the fuel filter, plugs, basically performed a tune up yet? Try something cheap and easy like injector cleaner. Either way - it doesn't sound like anything major...

 

I found a post on when he bought the '99 F250...

I would suggest buying from a better gas company.

Here are his specs:

 

Is it throwing any codes? All guesswork until you pull the DTCs.

 

Sorry guys, I should have listed my specs, thanks Manual for doing so!
I drove it to work today and noticed it again. Only now it's 0-70mph, and it seems to be interment(sp?). As I got closer to work though it seemed to smooth back out again. Today I'm going to get some fuel injector cleaner and get some 92 octane gas in it. I'll keep you guys updated here.... Thanks all!
Nope, no codes...... hope that means no major problems

 

The guy it was bought from said it was 'babied' (never near the RPM limit??)and since it isn't putting any 'codes' to be concerned with, it may be just a combination of old plugs, dirty fuel filter, and cheap gas...anyway, best of luck and Merry Christmas (sorry, I'm not too PC )

 

I dunno much about the 5.4's but my 4.2 F-150 was doing the same exact thing as what you're describing. Mine would hesitate and make a popping noise when I'd slightly touch the gas pedal and this happened at many different speeds. Long story short, it was my coil pack. Had that repalced along with new plugs and wires (part of my 100K mile service) and that resolved the issue.

 

Sorry for the delayed reply guys......
I finally just got enough gas used up to put some high octane back into the tank. Even after doing this much has not changed at all. In fact it seems to progressively be getting worse. So I'm going to be doing some general tune up stuff (wires, plugs, etc...)to see if that will cure the problem. If it does not, time to start troubleshooting. I really need my truck here by the end of the month to haul my Jeep out to Indy. Thanks again everybody, and please keep posting up for anyone that's had similar problems/cures. I'll keep yall updated.

 

Good luck - the 5.4L V8 is designed to run with regular gas (87 octane). Sometimes people get confused about the term 'cheap' gas. I really don't think it's a gas issue according to your last post(it should still run fine with 92+ octane). Gas at a lower octane actually ignites faster than high octane gas. Usually high mileage cars will run high octane because of pre-ignition or detonation. If your truck isn't pinging at WOT (wide open throttle) than stick with 87 octane.

'Cheap' gas to me means a local, old technology, unknown name brand in the boon docks. Who knows how long the gas has been sittin' in that tank in the ground.

Anyway, a good basic tune up should fix you up just fine as the other posters have attested...

 

See I always thought that the 87 stuff would not burn so well, leading to crappy gas mileage. Thinking I was doing the truck good I started using 89 to see if it would do any better and seems like it does. At WOT the truck will get up and move, even now with problem I'm having. I hope a nice little tune up will kill this problem, we'll see though. I'll post my findings up! Thanks!

 

bshaw - just so you know (in case you don't already) you are not doing any harm running 89, 92 octane. The 'recommended' octane for the 5.4L V8 and 6.8L V10 is 87. There are some beneficial additives that 'super' and 'premium' have...but the gasoline itself is essentially the same with the difference being the octane rating. Learn more by browsing the web on this subject. It will help you understand the difference better. From what I've learned the high octane gas is best for really high mileage engines, high compression engines, turbo & supercharged engines (basically). I'll admit - Occasionally I put 89 in my engine too!

 

I throw in some fuel system cleaner and a tank of 93 in my F150 every so often... but it hasn't been giving me any issues... so I can't see messing with it.

 

Thanks Pagnew for explaining that!
I wanted to post this info up that I found. I was doing some searching and found a guy who had a 2000 f250 with the 5.4 and was having the same problems as I am now. Long story short, he took his truck to a stealership. They found that the #7 COP (coil over plug) was bad. They had pulled a code off the truck, and his check engine light was not even on.
Since our weather here has been so crappy (20 degree highs) the last couple days I have not started in on anything yet, but will be here on this coming Thursday. I'm going to take to an AutoZone and see if they can pull any codes? Hopefully they'll be able to pull something..... If not, I really don't have a clue how to tell which COP would be bad IF this is my case????

 

sorry for the delay again........ found my problem. turned out to be my spark plugs, they were all ate up pretty bad. replaced all of them, which was bout a bitch and a half, and my problem went away. thanks again everybody!

 

Woo Hoo!! Glad it all worked out for ya!