Fuel Pump Relay?

[hivolt]

I have a 2001 S model that is not getting any fuel. I want to check if the fuel pump relay is bad before I drop the tank and change the fuel pump. Is there anyway to check them?

[millyowner]

You can hot wire the fuel pump relay to see if the pump activates via the Diagnostics connector under the hood.

[ken inn]

if you can swing it, get a fuel pressure tester. dunno if they can be rented, but if you test fuel pressure you can pinpoint the pump, or rule it out. i know of one other case where the pump was bad, iirc, it was also an 01 s

[yel-low]

Or the "cheap ghetto" and definitely messy/unsafe way.....
Crack the banjo bolt loose on the fuel rail and hardwire the fuel pump to turn on as MillyOwner suggested. Fuel should stream out of the bolt if your pump is good.

[hivolt]

Or the "cheap ghetto" and definitely messy/unsafe way.....
Crack the banjo bolt loose on the fuel rail and hardwire the fuel pump to turn on as MillyOwner suggested. Fuel should stream out of the bolt if your pump is good.[/b]

Thanks for the help everyone. Finally got a chance to drop the tank today, which ended up being about a 4 hour job. changed the fuel pump and she cranked right up. So def was the fuel pump. The crazy part about it was I forgot to change the fuel filter when I had it down. Guess ill just have to do that tomorrow from the top.

[Matt64341]

Thanks for the help everyone. Finally got a chance to drop the tank today, which ended up being about a 4 hour job. changed the fuel pump and she cranked right up. So def was the fuel pump. The crazy part about it was I forgot to change the fuel filter when I had it down. Guess ill just have to do that tomorrow from the top.[/b]

That's good to hear. Did you do this all on jackstands or did you have a lift?

[hivolt]

Got the job done with a bottle jack and two jack stands. It was alot easier than I thought.

[Saint_]

Off the topic, what is the point of sending the fuel to the engine first then and back to the tank? Newer cars (such as Mazda3) rotates the fuel inside the tank to create pressure.

[Xedosman]

Off the topic, what is the point of sending the fuel to the engine first then and back to the tank? Newer cars (such as Mazda3) rotates the fuel inside the tank to create pressure.[/b]

I don't follow you, rotates inside the tank? Do you mean rotates through the pump and fuel not used is dumped back without circulating to the engine compartment?

That is why it is returned to the tank anyway, regardless of routing. The fuelpump supplies pressure and enough flow to ensure enough fuel with full throttle, but during idle and regular driving most of the fuel is returned to the tank. Compare it with central heating in a house, a circulating pump ensures flow while each radiator takes what it is set to take according to regulator or valve. If the valve is shut, nothing flows through the radiator.

[yel-low]

Similar to what Xedo said...

The entire fuel rail is pressurized. High volume-low pressure is passed from the fuel tank to rail via the pump. The fuel fills the rail and is met by a diaphragm (FPR). This regulator bleeds off a small amount of volume (returns to tank) but keeps a high pressure in the rail. The only thing the injectors need to do now is pulse open or close to squirt fuel into the cylinder. The pump constantly runs to keep a constant pressure in the rail. You can modify the pressure your injectors see by aftermarket fuel pressure regulators. This increases the amount of "back pressure" seen in the fuel rail by an adjustable spring/vacuum pressure.

I'm not aware of any other method used in fuel injected cars.