i have a 2005 F150 5.4L while driving my message board bell indicated low oil pressure i pulled into the station and checked oil. i had to add about 2 qts i filled up with gas and the truck has not started since. I towed it home changed the oil, filter, oil pressure sensor and the fuel filter

when i try to start it the engine turns over normal no noises, knocking or anything out of the ordinary. It sounds like it wants to start but then acts like something is shutting the fuel pump down. I had the local mechanic tell me that the fuel pump was out. I can here the fuel pump kick on for no more than 2 seconds then shuts off. he told me it should pump for about 5 to 10 seconds. i am not convinced it is the fuel pump dont want to spend $300 on something i dont need.

is there a saftey cut off swith to the fuel pump when the low oil pressure indicator comes on? i also check the codes and its not giving any codes but i had removed the battery and replaced it and i am thinking that removed the codes?

Any advice on this would be greatly appreciated i am out of ideas


Thanks, Doug

 

Don't know about oil pressure inhibits, but I don't think so -- they USED to have them on some of the 80's trucks.

But, 2 seconds is what everybody says is the correct time for your fuel pump.

I've never done this, but people squirt starting fluid and the like into the throttle body to see if it will start that way. If it does, that says that there is probably a fuel problem. Could be a plugged filter.

Order of start
- fuel pump runs 2 sec to get things started
- truck fires and pcm senses that it's starting (not sure what signal)
- pcm turns pump to continuous on.

A common issue on these trucks seems to be anti theft. If you have an antitheft system, I've read that they act that way of they can't read the chip in the key. I've never had an anti theft system.

Good Luck,

hj

 

Thanks Ford2go i did try squirting starting fluid and it did not change the situation acted the same thats why I am not convinced it is the fuel pump. I am leaning in the direction of the crank senser. I am going to remove one of the plugs and check if i am getting spark if no spark then i assume i am having a firing issue. If the crank sensor dont work nor will my firing? So i guess it process of elimation. As far as the anti theft system i am going to look into that as well... thanks for the info

doug

 

well i checked the fire and i got fire so i can only assume the crankshaft sensor is still good.... so if i got fire and then that only leaves fuel. so question is what is keeping fuel from making it to the cylynders???? maybe it is fuel pump...so back to the drawing board....

 

Do a search for Fuel Pump Driver Module. Common for them to go bad due to corrosion. It's mounted on the rear axle above the spare tire. Watch the video in post # 6 of this thread to see what it looks like and location.

https://www.ford-trucks.com/forums/1...ont-start.html

 

That was the first thing i did after changing the oil, oil filter and fuel filter. i pulled it off and still looks real good cleaned it up and reinstalled it. I dropped the fuel line from the fuel filter turned the key and fuel pump pumps for no longer than 2 seconds so that is giving me the impression that the fuel pump is working (maybe i'm wrong). i also gave the intake a couple of shots of starting fluid it still acted the same as if i didnt spray it with starting fluid. so i figured that eliminated the fuel pump. and after checking for fire i figured i eliminated that also. I know it probly something simple i just cant put my fingue on it. so now i will stand back drink another can of thinking fluid and maybe something will get my attention....... thanks for your input.


Doug

 

If you have spark, check a plug after you crank it for a bit. If you are getting fuel, the plug should be wet with gas. Next thing would be a compression test.

 

The fuel pump driver module is a separate unit from the fuel pump.