I have a 1999 f-150 4X4 5.4, When I go to start my truck I can't hear fuel pump comming on, If I turn key off and on a number of times (until I hear it prime) will start right up and run fine. Seems the colder it is out the worse it is (Minnesota). The other day when it went to start it acted like it was flooded, this only happened the one time, otherwise you can crank and crank with no start unless you cycle the key off and on till you hear pump. I searched the archive's, alot of similar problems, but none quite like this. Is my fuel pump going bad or is there something else I should be looking at. Thanks for all input.. NORMALLY A GOOD RUNNER.. I have tried all 3 sets of keys, to no avail, Help.

 

Are you serious? How does it even start with the key off ?

I can't understand your writing - So does the pump prime? Not always? It only starts after your hear it prime up?

 

Not always,, some days it starts like it should, can go weeks like that,, every so often (like when it's cold out) when you turn the key "on" you can't hear it prime, so if I turn key to "off" and back "on" (still no prime) Key "off" and "on",,,, ect until I hear prime, then will start, and run great. You can crank on it all you want but if you didn't hear it prime your wasting your time.

 

I would check all wire connections related to the fuel system.

 

Okay , Yea I agree - bad connection or bad relay.

 

I'd be looking at the relay first, since it is the easiest and probably least expensive part to replace. There are probably a couple of the same relays used, you could just swap one for another of the same to see if it cures ypur problem before you buy a new one.

 

Thanks to all.... Ended up being fuel pump, finally gave up all together, replaced last night, and all is running fine. Keeping another 100,000 mile + F-150 on the road. Again I thank you all for your replies..

 

I think I am having the same problem you are? Sometimes it is hard to start but mainly only when it is cold. Feathering the pedal usually gets it started. Then sometimes after it being hard to start it wants to sputter like the plugs are all loaded up but if you floor it it runs just fine. I was thinking fuel pump, plugs or battery. 2003 Ford F-150 FX4 5.4L V8 79,000 miles, new fuel filter, air filter, original plugs and coils as far as I know and I have the correct battery with correct CCA but it is 2 years old. I have seen a slightly weak battery do strange things. How hard was it to drop the gas tank and replace the fuel pump? Any other suggestions about my problem? Thanks!

 

Glad you solved your problem. I assume you changed your filter?? Usually pumps that get weak will not prime a dirty filter very well and show weak under load or after they get good and warm.