My car will not start , it cranks but will not start. I tried about a handful of times throughout the day. I experienced this a few times, normally after getting gas, but it always started after the first time of having this issue.
I disconnected the fuel line hose in the picture and when I start, I am assuming fuel should be coming up from the hose that is coming from the tank, but nothing at all no fuel.
I also, disconnected the hose from the fuel pump in the gas tank under the rear driver side seat and when I tried to start, I see gas coming out from the pump.
So my question is, could it be the fuel pump from the gas tank or the fuel pump in the engine?
Is the fuel pump in the engine supposed to suck the gas from the tank or does the fuel pump from the tank supposed to do all the work and pump fuel to the engine?

 

anyone know how to hook up power to test the fuel pump?
i want to test the fuel pump that i bought and make sure it works before installing.
i have a extra car battery to test with, but dont know how to hook up the wiring.

 

You might want to ask this guy :

https://www.clublexus.com/forums/is-...-starting.html

So the hose in your picture, is that hose BEFORE the high pressure motor-mounted fuel pump to the right in that picture OR is it the return line to the tank (do our cars have a fuel return?)?

 

^I see you already visited that thread.

 

yes, that line goes to the fuel pump/regulator thing.

i wonder if the one in the engine is bad, would it stop the fuel pump in the engine from starting?

 

From what I gather, it takes a combined effort of both the in-tank and motor-mounted fuel pumps in order to make our vehicles work properly. So I'd say yes.

 

Do you have an IS250 or IS350? The fuel system in the IS350 will be more complicated with the dual fuel system of the FI & DI.

 

IS350.

so i tested the voltage on the in tank fuel pump assembly with multimeter, i touched the power wire ( there are 4 wires / 2 wires each that goes to purmp and gauge sensor ).

when turning the car to acc on position, i get the 12 volt reading from the pump wire for about couple seconds, which i believe should be normal.

When i touch the power wire of the fuel sensor gauge when turning the car to acc position, i get a reading of about 3 volts.

i think this should be a good indication that at least there is power running through the wires to the fuel pump. i also think this would eliminate any fuse/relay issue. would anyone agree on this?

 

If you agree the pump's "hot" wire is getting power, then yes...it should work. Have you attempted (with a full tank), slightly elevate the pump from the chassis and start it up to ensure it actually works? Don't allow the filter sock to leave the fuel level in the tank. Don't wanna burn it up!

 

Update: not only was my original pump bad, the pump I bought to replace was also bad. So the second pump I got today turned right on when connected.
Now at least I know how to test it before replacing. Lol. I did run the newest pump out of the tank first, but it was only for a couple seconds to make sure it worked before install.
I had to run the fuel pump via outside power to pump enough gas to the engine after install, otherwise the two second prime when turning the car on acc position didn't pump enough to start it.

 

Glad you got it working!