Possible bad fuel pump
 

Folks, I'v searched this forum and tried some of the trouble shooting tips but want to run everything by you guys just to make sure.

My 2001 4.6L F-150 has been sitting on the driveway, used once every 2 weeks or so for the last 3 yrs. I came to start it a few days ago and it kept turning over but not starting. The key security chip is working, battery is charged, all plugs are firing, fuel pump fuse and relay check good. When I turn the key to ON, sometimes I hear the fuel pump priming, other times it doesn't. The times it does prime, the truck fires right up. The times it doesn't prime, engine won't start. When the pump does prime, and while the engine is running, the pump makes a noticeable buzzing sound, much louder than normal. When the pump primes. fuel pressure measures at 42psi in the ON position, 36psi with engine running, and 46psi with engine running and vacuum hose removed. I believe all these are within specs.

My question is this: Is it safe to assume that the pump is going bad and will eventually fail completely? My second question is (and I know this can be debated til the end of time) should I get the Motorcraft ($288) or aftermarket? I have Airtex, Spectra, Carter, and Delphi ($165 - $210) available locally.

Thanks folks...

The prices you are give must be for the hole fuel pump assembly, or your really getting riped off..lol
If you need a pump, you only need to replace the pump, not the hole deal.
You can get all the pumps on rockauto . com for under 100 bucks.
The motorcraft looks to be pretty high on there though.

You can check for bad fuel pump two ways. The best is to check the fuel pressure on the rail. It should be like 38 or higher.

You can also spray.some starting fluid in the throttle body when it doesn't fire. If it sputters like it wants to start then you can assume the fuel pump is on the way out.

Check the electrical connection to the pump. That buzzing you here may be arcing. Also check your ground, that may be loose as well.

My truck did the same thing last year. If you heard the pump buzzing, truck would start. No buzz, no start. I had a mechanic check the fuel pressure. I can't remember the exact reading but I know it was too low.

I dropped the tank and replaced the whole unit with an Airtex from Advance Auto. About $150 or so (again, I can't remember exact price.) If you're going to pull the bed or drop the tank to change out the pump, you might as well change the whole unit out. Dropping that tank was a bear, I wouldn't want to do it to replace a pump, then drop it again for a sending unit later on.

It's been about a year since I installed the Airtex. No problems.