fuel pressure

[johnnyc]

i need help can somebody please tell me what the fuel pressure should be on a 99 explorer sport sohc 4.0 thanks

 

[Maniak]

My book says 40psi (give or take a couple) under normal operating conditions.. but can go down to 30psi at high vacuum conditions (no lower than 30)...

Not sure if you need it, but here is instructions on changing the pressure regulator..

http://www2.autozone.com/servlet/Ui..._us/0900823d/80/0b/9a/00/0900823d800b9a00.jsp

~Mark

 

[james t]

a 99 has returnless style... there is no pressure regulator... pressure is controlled directly at the pump via the computer. from what i understand its supposed to be really high, like 55 or 60 psi with the key on/truck off.

 

[Maniak]

eeek.. then my book is way off.. and so is the autozone web site..

sorry, I don't have any other books to look in..

~Mark

 

[johnnyc]

thanks guys for the help

 

[johnnyc]

see if i park on a hill with 1/4 tank of gas and let the truck sit over night it will not start the only way i get it started is by rolling it down the hill to level ground or put more gas in it now if i have a 1/2 tank it will start right up on the hill i'm sure the gas gage is right because when i get on level ground it will go back up and i can drive 50 or 60 miles on the same gas that it would not stat with

 

[metalhed]

Have you tried to turn the key to the acc position and let the fuel pump do it's thing, then turn the key back, repeat, and try to start?

I'm wondering if gravity is just causing a ruckus, and the engine just needs to be 'primed' before starting. Could be alot easier than going through the steps you mentioned before.

I don't know much about the newer models.. But I like to pretend that I know more than I do.

 

[johnnyc]

hi thanks for the reply yes i had tried that each every time but it still will not start until i get it on level ground

 

[Majisto]

Originally posted by metalhed
Have you tried to turn the key to the acc position and let the fuel pump do it's thing, then turn the key back, repeat, and try to start?

I'm wondering if gravity is just causing a ruckus, and the engine just needs to be 'primed' before starting. Could be alot easier than going through the steps you mentioned before.

I don't know much about the newer models.. But I like to pretend that I know more than I do.

May need to learn just a bit more there. The fuel pump will only prime when you turn the key to "On". Clicking it to ACC won't even power up the instrument panel lights.

 

[johnnyc]

thats what i do i turn the key on and off like 20 times but it don't help

 

[Nate1]

How steep is the hill? It may be that the gas falls to the back of tha tank and leaves the pump high and dry, so it does not pump anything untill it gets back on solid ground.

 

[MrShorty]

Thinking out loud, maybe someone who's been inside of one of these tanks can comment on this. I had a car once that had an updated part number on the fuel pump because the fuel pump intake got a hole in it that prevented the fuel pump from getting at the gas that it otherwise should get at. I'm wondering if your fuel pump or the assembly that "sucks" the gas into the pump has developed a crack or leak.
Also, I don't know what kind of mechanism exists inside the tank, but it seems like there's got to be some kind of mechanism to keep fuel at the pump when pointed downhill. That long narrow tank with the pump near the back, there's got to be some way to keep gas at the pump for going downhill and such. Perhaps there's a problem with that.
Any thoughts?

 

[MrShorty]

And another thought. How much gas do you put in after that extra 50-60 miles? Could the gas gauge be reading a little off so that when it's reading 1/4 tank, it really means "E"?

 

[johnnyc]

it's only when the truck is facing down hill and after the 50 or so miles then it will read on E it will take 6 dollors to get it back on 1/4 tank thanks for the reply