Fuel delivery issues? 2013 v6

2013 Tacoma, drove it to an appointment, sunny and 55*. An hour later truck won’t start. Cranks over fine but no fire. Will not start. Checked fuses swapped fuel pump relay added a few gallons of fuel, still no start. Fast forward a few days at home in garage, truck fired right up when I hit it with ether (starting fluid) at the air box. I then tested 11v at fuel pump wiring connector while cranking the engine over. I assumed bad fuel pump. Replaced with a new walbro255 and external fuel filter. Still no start. I rechecked pump, installation and tested pump in tank with a 12v power source. When I prime pump/fuel system manually with battery, the truck fires up instantly, and dies in 2-5 seconds. Struggles to fire on second attempt and then flat nothing, just turns over no fire. I have read the fuel pump is power by two circuits, one circuit functions while cranking with ignition key. I am un sure of what circuit powers the pump while engine is running. I believe it is linked in with an air flow sensor, but I don’t know which one or if it has an accompanying relay that may be bad.. a quick review, truck won’t start, getting no fuel, fuel pump is new and working, fuses are good, fuel pump relay is new, 11v to fuel pump while cranking. Truck fires and runs when pump is manually primed, until fuel pressure runs out. any help on what powers the pump while starting and what powers pump while it is running? Thanks in advance to anyone who can help me.

 

I forgot to mention the only codes I am getting are P1604 Start-ability malfunction.

 

Maybe this will help.


https://youtu.be/cICupuNpaoI

 

Fuel pump resistor is probably bad, disconnect it (located in front of the battery) and jump the connector end with a paper clip or other suitable jumper. Try and start the truck, if it runs, put a new resistor in it. And yes, all power to the pump goes through it.

 

^^ Great info. Bookmarked.

 

Yup this.

 

I had swapped out relays in the parking lot the first day it quit.. I bypassed the resistor as well, it was reading 11v at pumpwiring connector while cranking, did seem to be consistent or enough to prime and run pump. I traced the power wire from pump back under the dash and found this... I am going to solder in a jumper wire to bypass the connector and see what happens. Thank you all for the replies so far, I’ll post my results of what happens shortly.

 

Good find!

 

It was the burnt connection. It showed 11v on the test meter, but didn’t have the amps to run pump.. I just want to add to this post for anyone who might read it in the future. When I was troubleshooting the issue, I was still getting 10.5-11v at the pump wiring connector. My first thought was a bad pump. A brand new pump was installed, and the power supply to the pump was still testing 11v while cranking, but pump would not run unless I hooked 12v directly to it. Apparently even with the burnt connection it would still test close to 12v at the pump, but when pump was hooked up and drawing electrical current, the burnt connector could not provide enough amperage to run the pump. If doing it all again I would check for resistance or current flow between resistor under the hood and the pump connector..

 

Even 1 strand of copper wire will read voltage on a DVOM, but will not carry a load, that's why load testing and not just voltage or continuity testing should always be performed. Glad you got her fixed!

 

OK , found the weak link in the system, I get the jumper wire temp fix to verify the problem, so now what is the proper repair for this, a new connector, if this were a warranty repair what would a dealer do so that it did not reoccur ?

 

is that at the ECU itself?

 

Connector is on the driver side, as noted by the pedal in the back ground. Makes me want to check my connector, since I never upgraded the whole wiring to the larger pumps that I have run over the years. Especially with the age of my truck.

 

Hmm what do those pins actually go to (connector and harness side?)

 

It appears that the wiring to the pump is not enough to foot the amperage that even a stock pump is capable of running. That's a little nerve wracking...

 

That has nothing to do with the wiring.

The burning was from a loose fitting between the male and female terminals.
This loose connection equals resistance, a resistance in a wire is a heater.

That is what caused the burned connector. The wiring is just fine for the fuel pump full load amps.

 

Yeah true. I didn't think of a loose connection.

Probably a freak thing as you don't see it happening much on these trucks.

 

More common on the Heater Resistor connection on the blower.

 

Yeah that one is incredibly common.

Mine had an issue at the HVAC control panel itself. The wiring for the full 12v delivery wire was burnt up at the connector and at the control panel unit itself. I just tweaked the pin slightly and still have to put some electrical contact grease on it. I just minimize the amount of full blast run time on the HVAC for right now and usually just run it on 3/4.

 

Well this is true in most cases of normality, the wiring connector in tank showed signs of heat degradation on the factory side, due to the smaller gauge wire at that connection, on my truck specifically. Which made me replace the wiring in tank with larger gauge wiring. However that doesn't correct the rest of the wiring to the tank and any smaller connections in between. Which is what got me thinking about that pin and wiring for my truck specifically.

In all honesty, I have they have your gauge wiring already on the shelf which was for my pump. Just have been too lazy to do the work.