All right guys, I need some suggestions. I recently bought an '02 F150 SC Lariat 5.4 FX4. It had about 31K on it when I got it, but all indications are that it was never abused.

I was running low on fuel (1/4 tank) about a week ago and the truck developed a terrible miss. I thought it may be a coil pack going bad so I called the dealership and the service manager told me that it it would throw the check engine light if a coil pack was misfiring. He said I had probably gotten hold of some bad gas. I have been getting gas at that particular station for over three years without incident (but stuff happens)

I filled up with high octane gas (at another station) and the "dead miss" feeling partially went away, but the truck just doesn't have the "go" that it did before that original incident. I took a trip this past weekend and ran that tank through it and filled up again. I now have about 1/4 tank left again and still the jerkiness rears it's head every now and then. Took the truck in this morning to the dealer because it just doesn't seem to have the power that it had and the problem, of course, won't happen when the tech drives the truck.

Am I just dealing with an extremely "wet" and dirty tank of fuel here? Seems to me that I should have been able to "run" it out by now--40 gallons after the original problem.

The "Check Engine" light has not come on and no codes have been thrown. I put a can of drier in the tank yesterday. What else should I try????

It is running rough. If I didn't know better, I would sware someone had twisted my distributor about 5 degrees (Old School explanation)

Any help would be great.

Thanks,

Sidewinder

 

Try some fuel injector cleaner. And change the fuel filter. If you had crap gas the filter should have caught it and now it is cloged.

Regards

Jean Marc Chartier

 

My first actions would be to clean the MAF sensor and replace the fuel filter. These trucks really respond to a clean fuel filter, and because its so new, I would guess that its never been replaced.

BTW - the fuel filter shoud be changed every 15K miles.

 

Where is the MAF sensor and how should I clean it? I'll pick up a fuel filter on the way home.

Thanks

 

You might want to pick up the tools to change that filter if you don't already have them

Rob

 

Mine is right in the air cleaner housing, looks like a little air horn ment to scoop some of the air going through the intake. In it is a couple wires that heat up and are cooled by the incoming air. The resistance (or current draw?) is measured across the wires and the amount of incoming air is determined from that. This wires often get a little dirty and the performance decreases. Take some Electronics cleaner and spray it GENTLY on the wires. Be careful as they are very fragile. Some people have used alcohol and Q tips, but I think its two easy to break the wires and be left with a dead truck and expensive fix. If you have a K&N or other high flow oiled filter this can cause a dirty MAF sensor.

My bet is on the fuel filter, but cleaning the MAF certainly won't hurt.

 

feildthis has a good point. You will need a high pressure line disconnect tool to take the fuel filter off. These are cheap and usually easy to find in an auto parts store. They typicall come in a kit of 6 or 8 tools, however you will only need the one. I think its for 3/8" line.

 

This may possibly help,besides my personal truck,I drive a 99 ford f-350 with the 5.4 at work and it had what felt like a slight miss.I could really tell during acceleration.Well the mechanics replaced the fuel filter,no luck.Replaced plugs,no luck.The night shift mechanic hooked it up to an analyzer and found that the egr valve was stuck open/closed??.Replaced that and it runs fine.I never figured an egr would cause that.Anyways,thats my input.

 

I would start with the fuel filter. Every time I've replaced mine (once a year or 12-15,000 miles)..I have much better power. They are only $9.00 + tax.

 

New Fuel filter and a nice new bottle of Red Line SI-1 Fuel system cleaner. It will work with one dose!

Treat your truck to a $14. date. That's about all you'll have to pay to get her going again. (This is my guess assuming you don't have a "Check Engine" light).


G. Luck.

 

On some engines, running high octane gas actually makes the engine run worse.

If you've been running regular all this time and switched to premium, you may want to go through that tank of premium and refill with regular to see if the power comes back.

You can also try resetting the computer.

 

Picked up a fuel filter and a can of BG 44k injector cleaner at the ford delalership on the way home last night. A buddy had the necessary tools. By the time I got home, the "Low Fuel" light had been on for about 10 miles, so I got almost all of the "contamianted" fuel out. I changed the fuel filter and went to the station for a fill-up of 87 octane (the service manager told me to ONLY run 87 in this truck). Now she has her POWER back .

I'll get some contact cleaner at an electronics store and clean the MAF soon, but I think the new fuel filter has done the trick. I could barely blow through the old one in the direction of flow.

Thanks for the input guys!

Sidewinder

 

I love it when a plan comes togehter......