fuel pressure low?

after changing my fuel filter with the right filter i started having problems above 45mph its hesitating i went to ford and they said my fuel pressure was low or fuel pressure and supply down is exactly what they said and that i need to replace my fuel pump why would replacing my fuel filter do this.

any suggestions would be great

Welcome to the forum!

Since you don't mention the vehicle you are working on or the model year, I'm not sure this is possible, but did you make sure the fuel filter is installed correctly? Many vehicles have directional filters on them with arrows printed on the housing indicating the fuel flow direction. I don't imagine you took fuel pressure readings immediately before changing out the filter, did you?

-Rod

Welcome to the forum!

Since you don't mention the vehicle you are working on or the model year, I'm not sure this is possible, but did you make sure the fuel filter is installed correctly? Many vehicles have directional filters on them with arrows printed on the housing indicating the fuel flow direction. I don't imagine you took fuel pressure readings immediately before changing out the filter, did you?

-Rod

thx well the vehicle is a 1999 crown victoria P71 and unfortunately no i didnt check the pressure before it was installed and it is the right filter and the arrow is facing towards the engine but someone told me that Replacing the fuel filter removed a restriction. Your fuel pump was compromised due to the restriction in the old fuel filter. Consequently the problem is now showing because the fuel pump is working into a lower load and is having trouble keeping up. If you had not replaced the fuel filter you still would have had failure in short order. It is just that the fuel pump would have failed without warning. Fuel pumps working into a restriction work at a much higher load and as a result will wear much sooner than a pump working into a low restriction load.

what you think?

http://i528.photobucket.com/albums/dd326/SWIVLESWAVLE/utf-8BSU1HMDAwMDMtMjAxMDAzMjQtMTkwN.jpg (http://s528.photobucket.com/albums/dd326/SWIVLESWAVLE/?action=view&current=utf-8BSU1HMDAwMDMtMjAxMDAzMjQtMTkwN.jpg)

http://i528.photobucket.com/albums/dd326/SWIVLESWAVLE/utf-8BSU1HMDAwMDItMjAxMDAzMjQtMTkwN.jpg (http://s528.photobucket.com/albums/dd326/SWIVLESWAVLE/?action=view&current=utf-8BSU1HMDAwMDItMjAxMDAzMjQtMTkwN.jpg)

http://i528.photobucket.com/albums/dd326/SWIVLESWAVLE/utf-8BSU1HMDAwMDEtMjAxMDAzMjQtMTkwN.jpg (http://s528.photobucket.com/albums/dd326/SWIVLESWAVLE/?action=view&current=utf-8BSU1HMDAwMDEtMjAxMDAzMjQtMTkwN.jpg)

You've got the direction correct.

I would agree that a fuel pump working in to a load will fail sooner than one not loaded, but the rest of the logic I don't follow. Sadly though I don't have any suggestions for you on why your vehicle runs worse now than before the new filter was installed. If the fuel pump is original it's not unlikely that your 1999 would be due for a replacement though.

-Rod

thats ok man and i agree with you completely but its the only logic i have considering i had no problems before the fuel filter install and the low fuel pressure is there so i have no choice but to change the fuel pump but i needed a second opinion also ford did a diagnostic on it and said i need a new fuel pump

today they car didnt start up right away like usual and now im having slight hesitation under 50mph plus a drastic loss in power

Next time it doesn't start right away, turn the key off, leave it off for about 5 seconds, then turn it to the run position (not Start) for 2 seconds, off for another 5, then try to start it. If it starts easily that way, that's another indication that it has low fuel pressure.

-Rod

i seem to be burning alot more gas than before wouldnt low fuel pressure be the opposite

Do you happen to have an aftermarket reusable style air filter in the car?

-Rod

No I just have the reg. Paper filter my friend said that When a car isn't running efficiently, no matter what causes it, it will use more fuel. that true?

Hi,
All things being equal ,try a motorcraft fuel filter or any national brand name that is approximately the same size as original. worth 15-30 bucks to eliminate probable cause ,"problem started with filter change"
Luck,ed