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Fuel pump hums when key is turned on, but no pressure at the fuel rail

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Remove the line and check for flow. could be a bad filter or I have seen (but not often) that the plastic "gooseneck" from the pump to the inside connection to the fuel line is cracked, in which case the pump will pump but fuel stays inside the tank.

Posted on Oct 05, 2009


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My 2001vw passat some times won't start unless i use starting fluid.I have changed air filter and spark plugs. When i hook it up no codes come up

Troubleshooting steps:
  1. When you first turn the key on, listen for the sound of the FUEL PUMP (humming sound). If you just turn the key on but don't turn it to START, the fuel pump should run for no more than 3-5 seconds. If it does, continue troubleshooting;
  2. If the FUEL PUMP runs longer than 3-5 seconds, check for fuel leaks.
  3. Test pressure at the fuel rail. If pressure is erratic or too high at idle, replace the fuel pressure regulator;
  4. If fuel pressure is too low at idle, replace the fuel filter. Still too low? Replace the fuel pump and fuel pickup strainer.

Jul 30, 2014 | Cars & Trucks

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No Fuel Pressure

More likely the pump is not putting gas up to the engine's fuel rail.
With key on, not start, the pump should turn on for 2 seconds to put pressure in the line and fuel rail. Do you hear the buzz or hum from the tank with key on?
Did you put a fuel pressure gauge on the fuel rail's test port (shraeder valve), and find no pressure with key on? If so, you will need to check into the pump operation (assuming the fuel filter is not clogged). A quick test is to pull off the gas tank electrical connector, find the fuel pump wire in the connector, and use a test light grounded to a metal frame or a voltmeter. Check for power on the fuel pump wire, while the engine is being cranked over. If power then, your new pump is not working. It could be the ground for the pump, so you need to check that. If no power to pump, engine cranking, then you will have to find the fuel pump relay under the hood, and check the wiring to it. There is also a fuel pump fuse-it may be under hood or in the instrument fuse panel-need to find and check it.
If the pump is working and the fuel filter is clean, you should have gas in the fuel rail (which supplies the injectors with fuel under pressure). I have not heard of a pressure regulator problem that could cause no pressure, but then...
Post back what you find, or with comments. Hope this has helped a little.

Apr 12, 2014 | 2001 Saturn L-Series

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2003 Nissan Sentra turns over but won't start has 3/4 tank of fuel

Listen for a slight hum when you first turn the key (do not start the car, just turn the key to the last position before it would rotate the engine). The hum you are listening for is the fuel pump turning on. If there is no hum, there will be a pressure release valve on the fuel rail. check to see if you are getting fuel pressure (in case you have a really quiet pump)

Nov 29, 2013 | Cars & Trucks

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Is there a emergency cut off switch for this vehicle? I have changed the fuel pump and filter however vehicle still doesn't start. What have I missed?

All vehicles have an emergency cutoff switch. But did you check the fuel rail to see if it has gas under pressure when the key is turned on? When you turn the key on can you hear the fuel pump kick in with a slight hum for 2 or 3 seconds? Did you check the main relay for the fuel pump to make sure that it was good before you changed the fuel pump? How about the fuel pressure regulator? ARE YOU GETTING FUEL? Are you getting spark?

Oct 24, 2013 | 2006 Mercury Mariner

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Low pressure on rail

Fuel pump or fuel pressure regulator could cause that. I would say change the fuel filter first as it is under $20. When you try to start the car turn the key to "ON" but do not start it and listen for a 2-3 second hum, that is your fuel filter building pressure in the lines. No sound, no pressure from the pump.

Jul 21, 2012 | 2006 Kia Sorento

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Fuel Pump problems. Diagnostics shows a pressure loss.

pressure loss is either a bad fuel pressure regulator on the fuel rail where the injectors are, or a bad check valve in the fuel pump in the tank. usually the latter.

A quick test is to turn the key to on and measure pressure. Should be 40 psi. Pump will hum for 5 seconds and shut off if engine is not running. (Safety step).

Pressure should drop very little for 5 minutes.
You can cycle the key off for 15 seconds or until you hear the relay click off. Then turn key back on to start pump for 5 seconds again to build pressure. This will help get it started for the day as it builds pressure that bled down over night.

Please rate, thanks.

May 25, 2011 | Ford Ranger Cars & Trucks

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1996 chevy monte carlo problems

try start with starter fluid if starts than need to check fuel filter and pump again turn key and have u or someone listen at tank for hum of pump if hum turn off and open cap to release pressure check fuel filter and or replace if needed turn on pump and check pressure at straider valve on fuel rail by fire wall drivers side if pressure vehicle should start / if no hum at pump check connections to pump and test pump new doesnt mean free from defects repair or replace as necessary

Jul 23, 2010 | 1996 Chevrolet Monte Carlo

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Engine not getting fuel

When you turn the key on, have someone listen near the fuel inlet (where you pump your gas) to ensure that the fuel pump is running properly. If there is a buzz noise, or a hum, the pump is running and priming the fuel system.

If that is true, find a fuel pressure gauge and install it on the schrader valve on the fuel filter or injector rail, then turn the key on and check the pressure on the gauge. It should read more than 20 PSI.

If it does not, you may have a clogged filter or a plugged line between the pump and filter/rail.

Sep 30, 2009 | 1994 Oldsmobile Cutlass Ciera

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How do I know if the fuel pump is no longer working on my 2005 dodge magnum

u check the fuel pressure, u can also hear the pump (humming noise) when the key is cycled on and off, The fuel pressure test port is on the top of the engine in the fuel supply rail to the injectors, you will need a special test gage to test it.

Jun 05, 2009 | 2005 Dodge Magnum

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