I have 1 998 with 120,000 miles on it and I have noticed that when I am doing 55 -60 mph and floor it .... it seems to sputter and I do not have maximum power. I am going to run an additive through the gas that will clean the system out but could it be my PCV valve as well. What would cause it to sputter. When I am at idle it appears to sound okay.

Also, around 50 -55 mph it keeps slipping in and out of gear. I do not think the tranny is going because it grabs the gears pretty good. Any ideas on this?

Thanks in advance

 

it could be a coil pack goin bad or it may need new spark plugs, but at 120k it wouldnt be a bad idea to change them anyway if u havent already. the trannys probly fine it probly needs a fluid change though if its never been done also. hope this helps

 

I had a complete tune up at 110,000 miles and all plugs were changed then....the ONLY mistake I made was carrying it to Pepboys I guess

 

oh ok well then u could have water in the gas or the fuel filter could be clogged. if it only spudders sometimes it seems like a fuel issue like a fuel filter or the fuel pump could be slowly going but i dought that.

 

So, how do u hey the water out? Pour rubbing alcohol I'm the tank!

 

Put "Heat" In the tank to get water out.
I would suggest running a little "sea-foam" in the tank for a few tanks.

When's the last time you changed your Fuel Filter??
If its been longer than 25k, I would start here.

 

Where I the fuel filter located?

 

Drivers Side Inner Frame Rail.
Around the middle to rear of the front door.

 

I will have to look at paper work and see when the fuel filter was changed last. Do I pour the sea foam in the gas or oil or BOTH?

 

Neither. Put a bottle of Techron in the gas to clean the system. Put "Heet" in the gas to help remove water. Don't put them in at the same time.

 

What engine ? Sounds like a 5four problem, but I hate guessing, specially when it's the first thing the OP should post. Sorry, I have to know what I'm working on first lol.

 

i have the same issue every now and then in my 2006 with the 5.4 3v. i changed the fuel filter no change.

But i filled up with chevron and if went away. so maybe its just bad gas...

 

I let the gas run down just below 1/2 tank and put in Techron and now at a 1/4 it is running much better. I did a bottle of sea foam and was going to fill up and run it next......good idea or bad idea

 

Bad idea to use Seafoam. Techron is the only fuel additive officially approved by Ford, Seafoam is no better.

 

Ya, that's true^^ I forgot about that.
Thanks GLC for the reminder. Run that Techron in a few tanks. You can get it at Walmart for like $6.
But still check on your fuel filter. My old 2001 was having the same problem, changed the filter and it went away. But I change the FF every 10~15K in my 2006.

With all the ethanol in the gas now days, you never know the quality of the fuel now.