Fuel flow

[Reggit 0]

I have a feeling my fuel pump has joined the rapidly growing list of expensive bits to bite the dust on my car.

 

I don't think it's priming, but hard to hear due to traffic noise.

 

I've pulled the fuel pipe(arrow toward front of car on the pipe) off the injector rail next to no 2 cylinder, would I be right in expecting a healthe flow from that pipe with the ignition on?

 

As it is, I'm just getting a short splash of fuel out of the pipe.

[2cc 0]

That sounds about right to me. The fuel pump only gets a short pulse of 12v to prime the system when the ign is turned on, then it drops to 0v. The voltage is restored when the engine is started and the pump then runs continuously.

Know what you mean about the trafic noise - always when you least need it. You'll hear it better if you take out the boot carpet and parcel shelf.

You could try putting a permanent 12v onto the pump (connector under the boot carpet) and see if you get a decent flow. Someone on here is bound to know what the unloaded flow rate should be. HTH a bit

[Guest]

Even if fuel came out of the hose you have no real way of measuring flow to time or pressure so I don't think that would really help. You can test the fuel pump system in a few ways. You can do a system fuel pressure, risdual pressure, and FPR (fuel pressure regulator) test if you have a fuel pressure gauge that exceeds 4.0 bar, here's a link that covers that VR6 Fuel Pressure Testing.

 

If you have ever taken the fuel filter or pressure lines off of the car you will know that it takes a bit for the fuel system to prime so doing an electrical test on the ystem may be in order as well. The fuel pump relay on your car is located in relay position 12, if you pull it out you will notice it has 4 pins, two big and two small. Using the terminal numbers on the relay, terminal 30 (big one) should have battery voltage at all times. Terminal 87, this goes to the fuel pump and the other related components. Terminal 86 should have battery voltage with the ignition in the on position and the last terminal, 85 is a ground that is supplied by the ecu. Test for power at terminal 30 and 86 and make sure you have a good signal. If you want to have the main fuel pump running make a jumper and jump terminals 30 and 87 and this will activate the fuel pump for as long as you want but remember it won't shut off. You can also remove the plug from the fuel sending unit in the rear hatch (I have no idea what you guys call it), jump the relay as described above and then test for power at the sending unit.

 

If this were mine I would check all of the power signals, first at the relay then at the pump and make sure the system is working. If you think the ECU isn't turning on the fuel pump then jump the relay and try starting the car. Keep in mind that if the car stalls or anything the fuel pump will continue to run if the ignition is off or on.

 

The pumps in these cars do go, it can be from running around without enough fuel in the car or from a blocked fuel filter or even a defective fuel pressure regulator.

 

Hope this helps, Dennis