low speed roughness
New to here, but have found it very informative. Now i need help. I have 2000 , F150 ,4.2 v6. 93,000 miles, yes it gets a lot road time! At 90k I started haveing a slight hesitation at stop lights, missing sorta, almost dieing, but not quite. Done tune up, new plugs and air filter. No help, still doing it. I must admit, I am having trouble getting the fuel filter lines off of old filter, am I missing something here such as a special tool or just not getting rough enough with them? Any and all help would be appreciated, this one has me baffled somewhat. Thanks

 

ok...now that you are here, have you never changed the fuel filter? that could be a major part,. there is a special tool, looks, well weird, a scisors assembly. If the fuel filter has not been changed that would be my bet, cahgne it every 50k. BTW tool cost about 2.50-5.00 at auto zone or any local parts store.


BTW where you from? and are you comin to H-town? check the H-town thread for more info!

 

Welcome To FTE!

I agree about the fuel filter. It could also be the pump, but when the pump goes bad, you aren't even going to get the truck started. My old Explorer had that problem. Anyways, I'd change out the fuel filter first off. That's a really cheap way to go. The process is pretty quick too. Once you get the fuel filter scisors from the local auto parts store, it's a snap. I used to change them regularly on trucks. Very simple.

NOTE: My 95 Explorer had a 4.0 V6 in it. Before we found out that the pump was bad, it would shutter and hesitate at stop lights also. BUT, it only did about once a day or so. Good luck man!

 

Welcome to FTE! As mentioned, the fuel filter is easily changed with the $5 tool from the auto parts place. Be SURE to depressurize before disconnecting filter.
If you haven't already done so CHANGE THE PLUG WIRES.
I'll bet you that solves your problem - it did mine.
I do suggest Motorcraft wires.
Let us know how it goes!

 

Ok. Will get fuel filter pliers (spreaders). Thanks for the help, hopefully this is all it is and will solve my problems. I figured that there had to be a tool to help with those fuel lines. Thanks again guys.

 

BTW, no need to depressurze the system (*trust me) just wear goggles, a hat, something to cover your mouth, and some coveralls!!! and do not smoke a cigarette as fuel will be everywehre.....(ny preffered method!!) Have you ever seen the look on people faces when you pop a pressurized fuel line in the middle of the hobby shop on base? or in the street outside your house.

 

Hopefully spoken sarcastically!

Definately depressurize the system. (take gas cap off) You'll still get a little gas on ya, but it won't hurt.

 

I did, and would reccommend, unplugging the inertia relay which shuts off fuel pump in the event of a crash. After doing so, start the engine and let it runs until it dies (about 3 seconds).
The fuel system is now depressurized.

 

Hello. I'm having a similar problem on my 1998 with a 4.2L V6. The rough idling usually occurs first thing in the morning and at stop lights as well. I've also had times where the truck has had severe hesitation when I first accelerate but eventually works itself out. Also, the Check Engine light is not on.

I've changed the fuel filter, spark plugs/wires and all 4 O2 sensors with no luck.

I was wondering if anyone had other ideas besides the fuel filter? I hope that the fuel filter change works for you because this has been driving me crazy for a couple of months.

 

What about the fuel pump itself, or your fuel lines?

 

Could be a dirty MAF...

 

I didn't do anything with the fuel lines or the fuel pump. I would think that if I had something plugging up the fuel lines or a fuel pump issue I would see it in my gas mileage which has not really changed.....

What would be the best way to check out the fuel lines and/or pump? I'll have to check out the MAF when I get a chance.

 

Well the pump (I think) isn't easy to just check. Find the fuel lines and follow them to see if there are any pinches in the lines and so forth. I think for your truck, the pump is in the gas tank. Although I could be wrong. Are all fuel pumps in the tank?

 

Buy some throttle body cleaner and clean your IAC and throttle body.Remember to disconnect the battery first!

 

Seems like everything been covered, except maybe for a leaky vacuum line or possible condensation in your gas tank. Have you checked all your vacuum hoses? Seems pretty basic but I've seen a few cases where people have practically replaced everything else just to find a cracked vacuum line.

Tom