No fuel

[Scoop549]

Pump good,new relay

 

[Dirtman]

Press button

 

[Scoop549]

Inertia switch good

 

[Dirtman]

Voltage

 

[Curious Hound]

Don't waste too many words, guys. All these little bits and bytes in the cyber world cost money.

 

[Dirtman]

I gives what I gets...

 

[RonD]

Unless its a Motorcraft fuel pump "new" just means "NEVER EVER TESTED", new does not mean "it works", so grain of salt any any "new" part

Motorcraft parts cost more because Ford requires each one to be tested FIRST before it is packed for delivery, and the labor to do that kind of Quality Control is expensive, especially since they added that pesky NO CHILD LABOR thing

 

[rusty ol ranger]

Can you hear the pump come on?

 

[Scoop549]

Can jump at relay

 

[Scoop549]

What wire should have 12 v at relay

 

[RonD]

Both terminals on inertia switch should have 12volts but for only 2 seconds when key is first turned on so repeat key off and then on to see if you get that 12volts at inertia switch

 

[Gdbeast]

RonD im having a similar issue. what would be a cause that if I'm getting 12v from the fuel relay but only getting 7.2 volts into the inertia switch thats as far as I've tracked it thus far. I've replaced the ignition completely cleaned all grounds but still no luck.. and I'm not getting power to my obd2 plug to hook up a scanner

 

[Dirtman]

Obd2 plug shares a fuse with the cigarette lighter if I'm not mistaken. Common circuit for a blown fuse.

 

[RonD]

RonD im having a similar issue. what would be a cause that if I'm getting 12v from the fuel relay but only getting 7.2 volts into the inertia switch thats as far as I've tracked it thus far. I've replaced the ignition completely cleaned all grounds but still no luck.. and I'm not getting power to my obd2 plug to hook up a scanner

There is only 12volts for 2 seconds at inertia switch just after key on, it part of computers Boot up software
After that 2 seconds you will see 5 to 8 volts at inertia switch, that's from the computers monitor circuit, it has no amps just volts, so won't turn fuel pump
So totally normal to see that 7.2v after the 2 seconds with key on


Ford computers only turn on the fuel pump relay for 2 seconds with key on to Prime the fuel system, 2 second run time adds 10psi of pressure
Computer will turn on fuel pump relay full time when it sees RPMs above 400, cranking RPMs are only 200
This is a safety feature in case a fuel line should break in an accident
If fuel line breaks engine would stall, so be below 400RPMs, and computer would turn off full pump relay to prevent fuel from pumping out even with key still on