2005 won't start

[bp457]

Need some help with a 2005 explorer, 4.0L SOHC V6.
Engine will not start and stay running. No previous indications of a problem.
The engine turns over and fires once or twice and shuts down. I then get a "check Gage" light and in the display it says "low oil pressure".
I've changed the oil and replaced the oil pressure sending switch. Before hooking up the new sensor, I ran a wire from the electrical lead to ground to see if the oil pressure Gage would respond. It did. the arrow pointed to a good level. After hooking up the new sensor and turning the ignition switch to on, the oil pressure gage does not move. (Should it, without the engine running?)
I picked up an Actron Auto scanner and tried to read any messages, but all I get is "Pass, no messages". Could the messages have been cleared, as I disconnected the battery while working.
Any help will be appreciated.

 

[BrooklynBay]

Welcome to this forum! Disconnecting the battery will clear the codes. Do you hear the fuel pump prime when you turn the key to the accessory position?

 

[bp457]

Just went out and tried, and I can't hear anything when turning the key to accessory. I do hear some clicking when it is turned to "on".
Honestly can't say I've ever heard the fuel pump prime.
Thanks

 

[BrooklynBay]

Check the fuel pump relay, and the inertia switch.

 

[bp457]

Okay,
Got a location on those puppies ?
Thanks

 

[BrooklynBay]

The fuel pump relay is under the hood where the other relays, and high current fuses are located. The inertia switch is in the vehicle under a panel in the front. The exact locations vary depending upon the year, and model. Download an owner's manual if you don't have a printed version. Check the links in # 13 in my list of useful threads for more information: Dead Link Removed

 

[bp457]

Okay, I got them. I pulled the fuel pump relay and swapped it with the horn relay (same part) and the horn still works, so I'm guessing the fuel pump relay is ok. Maybe not, but until I go buy a new one it will have to do. I also checked the fuel pump fuse and the injector, fuel pump relay coil fuse. Both are ok.

The inertia switch (fuel pump shut off) is located behind the inside passenger side pane, about knee high. I'm not sure what the "feel" of the switch is suppose to be. It did not feel like it was tripped. I pressed it anyway. Is there a way to check if the switch is bad ?

Thanks again

 

[BrooklynBay]

Unplug the inertia switch, and use a continuity tester to see if it's making a closed circuit. You could use a jumper wire in the fuel pump relay socket to make the pump turn on without a relay to test the fuel pump.

 

[bp457]

ok. Will try it in the morning.
To be continued...

 

[bp457]

To jumper the relay. When looking at the bottom view, there are 4 pins, 2 horizontal and 2 vertical, 2 are slightly smaller. I'm guessing the 2 larger ones are the ones to jump in order to force the fuel pump on. Is this correct ?

My amp meter is on loan. I'll have to pick it up later today. should I jumper the inertial switch too ?

 

[bp457]

I jumped the inertial switch with no change. When I tried to start with the inertial switch unplugged and not jumped, the motor would not fire at all. when plugged in or jumped, the motor fires a couple times before shutting off.

I also jumped the fuel pump relay with the same results. when jumped or in place, the motor fires a couple times. When left out and not jumped, the motor does not fire at all.

my conclusion is that both the relay and the inertial switch are good, along with the associated wiring.

At this point I still have not heard the fuel pump. However I don't think I ever heard it in the past either. What does it sound like ?

I hooked up a jumper from the oil pressure switch to ground to see if the gage still works and the low pressure message goes away. It does.

what's next? Is there a way to check the fuel pump by pulling off the fuel line ? Is there anything else that could cause an immediate shut down ?

Thanks

 

[BrooklynBay]

See if there is fuel pressure at the test port on the fuel rail. There is a cap on the top of it which looks like a cap on a tire valve.

 

[bp457]

Ok, I give up on trying to find the valve.
I can see the fuel line coming up from behind the engine and split into 2 sections (must be the rails?) on top of the motor, and can see where it connects to each injector But, I don't see a valve.
I could email a picture if that would help.

 

[bp457]

Let me know if this works
Thanks for all the help.
Bill