12’ Tundra 4.6 fuel delivery issues

I recently bought a 2012 tundra, 4.6 L, from my wife’s grandfather. It had been sitting for a couple years. The truck started initially but wouldn’t want to idle and run, probably bad/old gas, and would die out within 10 to 15 seconds usually after turning on. So we dropped the fuel tank, emptied all the old gas and cleaned the tank. We replaced the fuel pump, and put a new battery. then we put fresh gas in, hooked everything back together. Truck fired up ran for a cpl minutes then died. Started again but chugging them dying and now we are not getting fuel pushed through any of the delivery lines and it will not start. Truck will crank and just not turn over. We used some wire and jumped the fuel pump to ensure it wasn’t defective. At this point we are at a loss.

I have seen online tjay potentially is a bad chip in the key that’s been worn down over time… I have the second key coming soon. Any other help would be greatly appreciated as we continue to investigate

 

Maybe a starter relay... if you have verified you are getting fuel that would be the next step.. the starting system

 

No issue with the starter, when it’s getting gas it’s starting.
The issue is we are not getting gas after changing fuel pump and putting a new battery

 

Fuel relays and fuses...may not be getting power to open injectors?? Find a way to test them on Youtube and go from there

 

We’ve checked relays and fuses switched relays and still isn’t coming on.

It can’t be the fuel pump if the fuel pump is kicking on with another source and we’re not getting power to the pump at the connector

 

If fuses and relays are good then you may need to check all wiring and connectors, check the fuel ECU.. since there is a power interruption somewhere inbetween.

 

That’s what we’re thinking it is, the fuel ecu/module (are they the same thing?)

do you happen to know where I would find it on a 2012 4.6?

 

I am 98% sure I located it, trouble I’m having now is locating the part.

do you know the technical part name I’ll need to find it?

fuel relay module/ecu?

 

Relay will be the fuse box. The ecu will be passenger side right panel or under the glove box behind the carpet..

 

The fuel pump control module is an incredibly common part across Toyota/Lexus vehicles. You should be able to find one in a yard, and finding the part number online that's specific to your truck shouldn't take more than a few minutes.

 

I think this is a good thing to go off of as this is exactly how it acts when you have the wrong key. Pull out a coil pack (if that's what it has never messed with 4.6) and see if you have spark. I think it may cut both fuel and spark if key is not communicating. I could be wrong though. The key has a chip that has to be programmed to the truck one way or another. Not sure what would cause it to just stop working all the sudden though.

 

Last night I unhook the battery for the advice of a bunch of different forums, came out this morning re-hooked up the battery. The fuel pump is now turning on upon ignition and delivering the initial fuel needed to start the truck, and then the fuel pump shuts off almost immediately after truck starts and runs for 10-20 seconds

 

Sounds to me like a clogged fuel filter causing it to run out of gas due to the flow being restricted at the dirty filter

 

As I stated at the beginning of this thread, the fuel filter is brand new which is inside the fuel pump assembly, which is recently replaced in the last few days. We pulled the entire tank cleaned everything, emptied all the old shitty gas, then cleaned the inside of the tank.

The fuel pump is running and giving gas upon ignition, and then shuts off within 15 to 20 seconds

 

Pretty sure there is an external filter on the frame rail bud. Might need to google it to verify, but I'm pretty damn sure.

 

Just an example above

 

There is no external fuel filter on the 2012 Toyota tundra 4.6 L. We’ve checked everywhere and we just talk to my local Toyota dealership and they didn’t say anything about there being an external, just the fuel filter found within the pump assembly in the tank

 

If I were you I would be going to my local autoparts store and requesting the part. When you have it in your hand, then you can look at it and verify. Just my opinion as a way to verify who is actually correct. Good luck!!

 

Pretty sure OP is correct. I've heard this numerous times that the newer trucks don't have external fuel filters. Looking on rock auto no fuel filter option shows up.

 

Not sure why I google it and hit shopping button all kinds of external filters appear. Maybe it doesnt have one but I find that difficult to believe.

 

If you click on either of the first two and put in vehicle info it with 4.6 it says they don't fit.

 

Lets think, order, screen then pump. So failed pump seals and such can go to injectors because there isnt any filter down stream??? Doubtful!!

 

Not sure what the part is but no way would an engineer not have a filter prior to injectors.

 

the fuel filter is internal in the fuel pump assembly. I talked to my local Toyota dealer today. No external fuel pump on 2012 tundra 4.6

 

Back probe and Put a multi meter on the wires that connect to fuel pump at the top of tank , start it and get readings find out if its losing voltage before shutting off , could be a broken wire or bad ground if you have checked everything in the fuel system. Also a words of advice "just because its new doesn't mean its not faulty"

after eliminating that its not a ground issue or wire issue at the fuel pump move to the relay and test it for voltage and that its not randomly turning off , (if theres a similar relay in that block for something else thats non vital and same amps and all swap it and see if it fixes issue just to rule out the relay)

if nothing yet has fixed this issue then test power at the injectors for each one an see if they are firing correctly.

but the first couple real questions are
Did you prime the fuel system after the pump install? Are you battery terminals clean and tight? Is the battery getting its 14.2v charge while running? All can cause a electrical gremlin issue. And is the air filter clean and unrestricted?