CanI tell if my fuel pump is bad because I do not hear a buzz in the tank?

Question

1999 Chrysler Sebring

Answer 1

You do not always hear a buzzing noise, especially if the engine is on. On some cars, the fuel system cannot sustain the pressure in the fuel when the engine is off so when you turn on the engine after it has been sitting, the fuel pump will start pumping so that it builds the pressure the fuel system needs. On some vehicles, even if the fuel system is low, the pump will only work for about 3 seconds and then shut off

Answer 2

Could be other things, but is usually the fuel pump on something this old.



It could also be a wiring problem to the fuel pump. Broken wire, corroded wire, etc. You need to make sure power is getting to the fuel pump.



There is a relay for the fuel pump. A relay is essentially an electronically activated switch that allows a low amperage circuit to activate a high amperage circuit. Relays can fail.



It could be a computer issue. The computer tells the fuel pump when it should be on.



The pump doesn't run continuously when the engine is not running. After the fuel system builds pressure, the pump should stop until needed.



Are you positive there is no fuel pressure? On the fuel injection fuel rail there is usually a Schrader valve used for maintenance. Using a rag to catch spilled fuel, open the valve to see if there is any fuel pressure. Should be around 50 to 60 PSI, so the fuel should be under pressure.



If you are sure power is making its way to the fuel pump and that there is no fuel pressure, chances are good that you need a new fuel pump.



Not an easy fix for the average shade tree mechanic as you usually must remove the fuel tank to access the fuel pump. However, on rare occasions the vehicle manufacturer will install an access panel for the fuel pump. The fuel tank is located under the car, under the back seat. I would take the time to remove the back seat to see if an access panel exists.

Answer 3

Signs of a bad fuel pump:



Don't hear it operate.

Car won't run.

Car stopped running.

Car is old.



PROOF of a bad pump.



Has power through relay to in tank pump, no fuel pressure, pump not running.



If you find that, you can tell. Just not hearing it may be a good guess, but it is still a guess.

Answer 4

The ultimate answer is whether there is fuel pressure. The sound of the pump will change depending upon the amount of fuel in the tank. You can buy an inexpensive fuel pressure gauge at the auto parts store. Maybe they will even test it for you. I don't recommend it but you can also trigger the pressure tap to see if fuel sprays out... but please don't set yourself on fire! A lack of fuel pressure will likely indicate a bad pump; although you need to watch out for a clogged fuel filter as well.



This car is old enough to qualify for such a problem.



http://ask-todd.com/?how-does-fuel-injection-work

Answer 5

the best mechanic around don,t know everything ! a bad relay or the pump fuse is blown will cause the pump not to buzz !

Answer 6

That is a good clue if you are getting no fuel to the engine.