My husband and I recently bought a 2000 Ford F150 4.6. It seems to idle a little rough so I thought the fuel filter might need replacing. I found instructions on how to replace it but seemed a little too involved so we called a well respected auto repair store to get an estimate on getting the filter replaced. They told us that replacing the whole fuel pump is required to replace the fuel filter. Why are there all sorts of videos on replacing the filter, including a special tool required, when the whole fuel pump needs to be replaced? Did the auto repair store hand me a bunch of bull***t?

 

They are probably talking about the screen on the pump inlet. Sometimes called a sock. Weird that they didn't understand that you meant the inline filter. You could probably find some neighborhood kid with a Ford and pay him $50 to do it.

It wouldn't be the source of your idle problem though. Filter problems would be more apparent at higher fuel usage. Not idle.

Also called a fuel pump strainer, apparently. It's a rough filter, to catch any big stuff. The inline filter catches the small stuff.

Strainer -
https://www.rockauto.com/en/catalog/...+strainer,6212

Filter -
https://www.rockauto.com/en/catalog/...el+filter,6200

 

Thanks so much for the quick reply. If not the fuel filter, what might cause the rough idle? We put in injector cleaner and gas treatment.

 

Add more details and someone might have ideas. Mileage, history before you bought it, what you've done to it since you bought it, type of transmission, any aftermarket parts, etc.

I'm not a Ford 4.6 expert, I just know that clogged filter and rough idle don't really go together. How old are the spark plugs? Have you changed the air filter? Have you cleaned the MAF sensor? A simple tuneup might straighten things out.

 

Thanks for the ideas of what to check for. I guess we have a little more investigating to do!

 

Normally if the fuel filter is plugged it will idle fine it will start sputtering at higher RPM. What BareBonesXL posted is good place to start.

 

Thank you!

 

I agree with everything BareBones said, except never attempt to clean a MAF. They're robust when left to work, but delicate when sprayed with anything. At most, use canned air (not shop air) to blow backward through the element.

You can't just think what's wrong with a vehicle. If you can't diagnose it logically, pay someone who can. But "idle a little rough" is too vague a symptom to diagnose anyway. Especially on a 21-year-old truck. Read this page & put all the details & history into your signature:

(click this text)

 

Well, we went ahead and had the new in-line fuel filter installed (my husband insisted and it was only $15) and changed out the air filter. It seems to be idling somewhat better. The air filter was BLACK. I don't think the past owner ever changed it. I can't believe the dealership didn't do that. Evidently they never even looked at anything on the truck.
Anyway, thank you to all that replied and I'm glad I found this forum.

 

I sprayed the heck out of mine with CRC MAF sensor cleaner. It's just a strong solvent that blows off dust and oil, then evaporates completely.

I get the advice of not cleaning a throttle body but I think the MAF sensor wires need to be clean, and the canned products are made to do the job. I know that CRC needs to sell stuff but their reasons seem sound.

https://www.crcindustries.com/produc...-11-wt-oz.html