Fuel delivery issues? 2013 v6

If it was the wire itself being undersized the entire wire would show signs of overheating.
When the burning is restricted to a local connection point the problem is that connection point. Granted the heat would or could go maybe an inch on either side due to time.

 

Maybe the pump was starting to short and drawing too much current. The weak spot in the whole circuit was that connector so it showed the signs of heat

 

This is my thoughts. I never had a know issue with the wiring before it just didn’t start. My guess was, when pump started to die it created excessive draw on system and got hot at the weakest point. Or the connection started to burn and short, causing the pump to fail. Truck had 1/4 tank and I ran her pretty hard down the highway, running late to an appointment. It apparently didn’t like that. Shut it down and it never fired again until I replaced fuel pump. and then it ran like shit (intermittent fuel pressure) until I found burnt connection. It never burn a fuse thought.

 

does the electrial load for the pump actually run through the harness inside the truck? I could see maybe the signal wire for the fuel pump relay, but not the actual main feed to the pump.

Off to the wiring diagrams i go.

 

this..

The pump failing caused the burn spot. A burned spot couldnt cause a pump to fail, it would just deprive it of power

 

From what i can tell the main power for the fuel pump from the fuel pump relay doesnt go through the cab. Those pins look like they could be the trigger wire for a relay though.

Edit. NVM. that connector is IB1, pin 8 (top row) is directly from the pump relay that OP shows fried. Very surprised that main power wire isnt just ran down the wheel well / firewall, along the frame rail right to the tank.

 

Last comment I have on it. I think it is a sure thing that the old fuel pump is just as good as it ever was. If you connect it to a 12 volt source I'd bet it runs just fine. (Don't do it for anything but a short time as running it with no fluid will damage the pump).

 

FYI here at the wiring diagrams. now what are the other pins in there for, specifically the larger pins (1 2 8 9 10 11 17 18)?

 

You are probably right. I came to this after replacing with a pump I knew was good, and still didn’t run. My mistake was not load testing the power supply. I just checked voltage at the fuel pump connector while cranking, it read ~11v so I thought that was okay. When new pump didn’t run either I had to dig further. Pump power supply wire ties into the main harness on drivers side frame rail. Runs into the cab right under the drivers seat and into drivers the foot well, harness splits into about 6 or 8 connectors. One of them with the black with red trace positive fuel pump wire. Lesson learned; check resistance or load test before I replace components. That being said. I’ve put 30k mi. on the truck since I bought it used &70k mi. It now has a new walboro255 and an in-line filter I can change whenever it needs. So it is not a loss.

 

The black with red trace 14g fuel
Pump wire was the only wire utilizing one of the large ports on the connection. Iirc there wer 4 other smaller gauge wires separated to the other side of connector. Fuel pump positive wire was on its own.

 

I had read though it seems hundreds of pages on this forum researching this issues. This place is an encyclopedia of Tacoma. It could be deja-vu (sp?), maybe came to me in a dream, but I am pretty sure I read one post, on one thread, somewhere on here, where a guy had a fueling issue and it turned out to be the same burnt fuel pump wire connector. I can almost see the pic in the post. but I can’t find it again. Anyway this burnt connector might be more common than we know. Hope this thread is useful for someone eventually. Thanks for all the help!

 

Interesting. Wonder why they used such a big plug for all of 5 wires.

Whelp good to know. I assume that connector was in the drive side kick panel by the clutch (manual) or dead pedal (auto)?

 

Another thought that may be a possible consideration. I have pinned/depinned hundreds of terminals from their connectors. Once in a while, but not often, I have run across a qestionably crimped wire in the terminal. These are all done high speed by machine of course and a slight out-of-calibration event seem to be quite possible and the few I have seen appeared to be that way. Inadequate crimping = higher resistance obviously.

 

Digging this old post up - I am having a similar issue and before going through the time and expense of a new pump, want to rule out other possible causes.
Where is this connector? I want to give this a shot.
I've already put 12V power directly to the red/black wire that goes to the resistor. Not sure if powering at the connector you show would do the same thing?

I created a thread for my issue:
https://www.tacomaworld.com/threads/2013-4-0-cranks-doesnt-start-sudden-fuel-pump-failure.752636/

 

There is a connector above and forward of the gas tank that connects the Fuel Pump and the Gauge assembly. You can jump 12 VDC to that connector on the black wire with a red stripe (+) and the white wire with the black stripe (-).

*** Note for safety connect the wires to the pump connector first then connect at the battery to prevent any sparking near the fuel tank.

Pretty sure the engine has to be cranking (ecu has to see the crank position sensor changing states) to get fuel. Just turning it on isn't going to do it.

 

I think we solved it in his thread, appears it was a bad connection in the IB2 connector under the dash.
https://www.tacomaworld.com/threads...fuel-pump-failure.752636/page-3#post-26817800

 

Heads up i had this exact same issue happen to my taco, left me stranded on the side of the highway while on a road trip. My tacoma is a 2015 v6 and only has about 95000 miles. I had previously pulled this connector and looked at it but it seemed to be fine, no corrosion or visible damage and wiggling it around didn't start the truck. I replaced the fuel pump and it ran for about a week before it died again due to this connector. I haven't even hit the 100k club and my taco already left me stranded twice i must have the worst luck and no maintenance could of prevented this.

Toyota was a ripoff charging me $700+ to replace the pin and they literally took all day to do it. Went into the shop at 9:30, they informed me about the damaged pin around 12:30 and that it would be a 3 hour repair. I debated, but the service reps were real defensive about it and i begrudgingly accepted it since i was desperate to get back on the road already.

3 hours later... "oo no they're still working on it, its actually a 4 hour job" this time i literally broke down the process of replacing the pin to the rep and said this is a bigger lie than trying to tell me an oil change takes 4 hours, they still wouldn't budge from their lies. Eventually they completed the job and got the truck back at 5:30. i inspected the pin (which only took 20 seconds to access and unplug the IB1 connector) and see they did replace it with a gold pin and the truck did run. I was upset and in a hurry so I just left at this point but should of told the rep to come outside to see this and explain why it took all day.

Long story short, dont be like me, Toyota will take advantage with no lube. Repair the pin yourself or just cut the wires out of the connectors on both ends and splice em together if your stranded on the side of the road like i was then you can do a permanent repair when you get home

Avoid Jim Ellis Toyota in McDonough, GA if you can. They are not trustworthy folks.