How To Tell If Your Fuel Pump Is Bad And Needs To Be Replaced

Be Sociable, Share!

    On older classic cars the fuel pump was part of the engine and cars that had carburetors had a fuel bowl that would hold enough gas to get your car started and allow the fuel pump to start pumping gas to your engine. Today most cars even carburetored engines have an electric fuel pump that sends fuel to the engine but all fuel injected vehicles have them and its probably likely that your car has a fuel injection system.

    When the fuel pump goes bad then your car will crank but it won’t start. The longer you try the more likely you are going to drain your battery and also need a jump start in addition to fixing your fuel problem if you even have one.

    Before you go checking things you can make sure that its not the fuel pump but using your ignition key. Its a really simple test. Turn off your radio and it needs to be quiet. Put your key in the ignition and turn it to the on position which is the notch just before it cranks the engine. You should hear a soft humming noise and that is your fuel pump. If you hear nothing it might be that your fuel pump is quiet enough that you can’t really hear it but normally you can always feel and hear that 10 second hum when the key is first turned on that means fuel is being pressurized in your system to prepare for starting. If you do hear the fuel pump working then you know its working and you can move on to something else and if you really want to ease your mind about it just remove one of the fuel lines from your fuel filter that is under your hood and turn your key to that on position and you should hear your fuel pump pumping fuel all over your engine.. no use a container to catch it but it does pump fast so only test it for a second or two.

    Checking Your Fuel System If Your Fuel Pump Isn’t Running

    The first thing you want to check is if any of your fuses are blown. Blade Fuses are pretty easy to diagnose you just pull one out and see if the metal ribbon has melted in the fuse. They also make testers that let you see if the fuse is any good in without pulling them but its a good idea to check the back of your fuse box plate for a diagram and you should see one that says fuel pump. If not you can check them all just do it one at a time.

    The next thing you can do is check if you are getting power to your fuel pump. Many vehicles have access to the fuel pump from the back seat. You will need to remove the back seat and the plate that covers the fuel pump. Using a volt meter check the incoming power connector for voltage when you turn the key to the on position. If you have voltage then you pretty much know your fuel pump is not working and needs to be replaced.


    Final Note

    Fuel Pumps do go bad and other things can contribute to problems in your fuel system. If you have a fuel pump that is working but you have a completely clogged fuel filter and this has happened to me a few times it can block 100% of your fuel pressure however most of the time your vehicle will have running problems like stalling out or loss of power if your fuel filter is beginning to get that clogged. I think in the cases that I found the filter was the problem that the vehicle was an older car and it had been sitting for an extended period. The system needed to be flushed completely including removing the gas tank and for good measure it was replaced since a spare was available in the used parts bin and it was in perfect condition.

    Cars want to run except when something breaks. The computer systems that control all aspects of your engine compensate for many things and can make a poorly maintained vehicle run well enough until it just dies. This is why you should do regular maintenance on your vehicle and also research problems you might have to fix in the future. If you don’t have a problem today its always good to have read a manual on what you might need to do if that problem happens. Either that or expect very high repair costs from your mechanic.




    Be Sociable, Share!