So after I replaced my fuel pump nothing happened. I then decided to check if I was getting power to the sender unit and no power whatsoever. Any idea what causes this to happened and what can I do to solve the issue thanks?

 

Describe how you tested the circuit. The pump will not prime or run with the key to ignition (like most modern cars). The pump primes/runs during crank and run.

Jumper the test connector in the engine bay (should be a 2 pin connector with a brown wire and black wire), key to run. Then see what's going on.

From there I would suggest using the FSM to trace through the fuel relay and fuel pump resistor circuits.

 

So as I was looking for the black and brown wire this came across. Could this possible burnt my sensor unitAttachment 740373

 

Don't know if it posted up

 

The yellow wire looks aftermarket. Where is it going? Could be someone's poor attempt at the bandaid fix of a fuel cut switch or something.

 

Hey my dude I'll check it out tomorrow and let you know. Thanks guy for responding stat. Much appreciated

 

 

The yellow connector to jump.

 

Once I connected the wire. It didn't do anything. All I heard was humming noise. So I'm still stuck with it trying to start.

 

I'm assuming you have a multimeter, yes?
This is a very simple circuit, did you ever reference the FSM schematic, like I suggested? I have pulled the pertinent page for you.

With the fuel check connector jumpered, the circuit opening relay should make contact and pass voltage on to the fuel pump resistor relay. Check the circuit opening relay for voltage on L/R wire.
If no voltage, check B/W for voltage.

Assuming the circuit opening relay is working, move on to the fuel pump resistor and relay. Check the voltage on the L wire to the pump. If you have no voltage out, but voltage coming in on L/R, you have an issue with this relay as the resistor is always connected. The ECU will short out the resistor for higher pump voltage when needed, but that's besides the point for this scenario.

 

If the relay is shot. What causes that to happened? Curious to learn and educate myself with these engines.

 

They are electromechanical switches, so after 30 years of heat, vibration, actuation, and current passing through it, it's not unheard for something internally to fail. It could also be as simple as a wiring/contact issue due to corrosion, not the relay itself. Relays are typically very robust.

Perform the tests, collect data, and let's see where you're at.