Hi,
There is going to be a fuel pump relay.
Usually, when you turn on the key - the ECU will fire the fuel pump relay which will
power on the fuel pump for a short time BEFORE you even get the key to the start position.

This is to put fuel pressure at the injectors so that when you crank the key - the fuel pump goes on.

OK - there is a little round device on the firewall on the passenger's side.
This is IN LINE with the fuel pump.

This is an inertia switch.

If you get into a wreck - this switch trips from inertia and it disconnects the voltage
to the fuel pump. This is so that when you have wrecked the fuel pump cuts off to prevent a fire.

So, if you disrupted the wires to this little inertia switch, your fuel pump will not run.
Look for it. Looks like a grey odd looking thing on the firewall.

Make sure it is plugged in.

Google is telling me fuel pump relay R103...

reading there is a fuel cutoff button

Start with the fuel cutoff......sometimes they need to be reset. Step 2 would be the the fuel relay.........I doubt that the fuel pump is not working as you said you can hear it engage. Let me know if you need anymore help.

have read many forums in regards to finding and locating the fuel pump relay, and most all say the same thing ( its the relay with a blue base, underneath the dash front of passenger seat)...

 

Hi Guys,
I just pulled the upper intake back off to double check the wiring under it. All of the wiring looked fine. Not sure where to go from here. I'll recap what i have done and checked.

The problem is I'm not getting any fire to the plugs and the fuel pump is not coming on at all, not even for the 2 seconds when the key is switched on. It cranks over fine.

The fuel pump will turn on if I jump it from the fuse box.

All the fuses under the hood are fine, including fuse #10.

The inertia switch is pressed.

I checked the main relay and that seems to be working. I swapped the FP relay and the main to check the FP relay and the FP relay seems to be working.

Do you think it could be the ECU?
I'm not sure where to go from here. Any ideas?

Thanks,
Jason

 

Fuse 13 in underhood box runs the main relay, which is ahead of fuel pump relay. Better check that as well.

ECU could be an issue, but ECU turning on main relay as well? Can you arm/disarm alarm system?

 

The #13 fuse is good. I can arm and disarm the system with the driver's door lock (the key fob does not work).

 

OK.

So alarm is turn off and truck should not be immobilized.

Truck turns over, so starter relay is being engaged by BCU.

With key in position 2, the main relay should be on. Remove/ replace fuse 13 in underhood fuse box to see if it is clicking. Main relay has to be on to enable fuel pump relay, but starter relay takes a separate path. Alternate test method - remove fuse 1 under hood, meter for 12 volts between each side and ground. Should only be on one side, and only when main relay is energized.

The ECU switches on the main relay and the fuel pump relay by supplying the earth ground for each circuit. You would want fuses that run the ECU (like #12) to also be good.

 

Okay just to be clear the truck was running and starting without issue before the head gasket job right?

You did pull the engine out so I'm still leaning toward a security issue. I read your post that your security light blinks after 10 seconds, but mine blinks really fast right after locking it from the door and then starts to blink slow after that. So I started wondering if the fact that you have a 10 second pause instead of that 10 seconds of rapid light blinks could be an issue.

I started messing around with locking and unlocking the doors and I may or maynot have found something. If I have the hood open and try locking the truck then the horn will honk and the red light will not come on until 10 seconds later. With the hood and all the doors closed the red light will flash rapidly for the first 10 seconds and then blink slowly after that.

What I'm thinking is maybe the lack of those rapid flashes in the begining could be a problem. Maybe try closing all the doors and hood and try locking the doors and look to see if you get that rapid flash from the red light. If you do then lock and unlock it a few times and try starting it.

This might not help anything but it's free and worth a shot.

 

As of right now I still have the hood off the truck. I will put the hood back on and close it and see what happens (can it really be that simple). If that doesn't work, I will do the test Savannah suggested. I'll let you know what happens. Thanks again, guys.

 

Hold hood switch down, or unplug it. Don't need to wrassle with hood at the moment.

 

Hi Guys,
I tried the hood switch theory and that did not do the trick. I also checked all the fuses under the hood again, they all look good. I tested the main relay, it seems to be working properly. I pulled the fuel pump relay and with the switch at the #2 position 2 of the leads are hot. I swapped out the FP relay with a couple other ones in the fuse box but still won't start. Still no fire and no current to the fuel pump. Is there anything else I can check?

 

re: I pulled the fuel pump relay and with the switch at the #2 position 2 of the leads are hot

When doing the above test, where is the (-) lead of your meter? Where is the (+) positive lead? If negative lead on frame (ground or earth), one would expect +12 volts on two pins of the base of the relay, one side of the coil, and the supply side of the contacts.