At Fixya.com, our trusted experts are meticulously vetted and possess extensive experience in their respective fields. Backed by a community of knowledgeable professionals, our platform ensures that the solutions provided are thoroughly researched and validated.
Fuel pump doesn't come on when switch is turned on.but after turning engine over it comes on for a second when you stop turning engine.1999 mitsibichi . changed fuel pump relay switch didn't help.
- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
When you first turn the key to start the vehicle the PCM - engine computer energizes the fuel pump relay turning on the fuel pump for two seconds to prim the system . The fuel pump won't be turned on again till the PCM receives a crankshaft position sensor signal. If you hear it come on the inertia fuel cut off switch is OK . Now then what problem are you having Lisa ? A no start condition ? Is there spark getting to the spark plugs ? Do you have a red light on the dash flashing when trying to start the truck ? Anti-theft system problem .
If it did run out of fuel, and apparently that is possible if you immediatly put some in, you may have to cycle the key on and off to get the fuel up to the engine again. You should be able to hear the fuel pump cut in and run for about 3 seconds when you first turn the key to the "run" position, and then stop. You could remove the gas cap, and have someone put their ear to it while you turn the key. If you don't hear it run, it may be the fuel relay switch if you're lucky, or the fuel pump if you're not.
It sounds like the pump is failing. That or sometimes not getting electricity. To check which it is, you could use a voltmeter or test light at the gas tank's electrical plug in. You need to check for power on the fuel pump wire when the engine is being cranked for starting. Do this when turning the key to on does not cause the pump to turn on for 2 seconds as it should. The fuel pump has power for those 2 seconds when key is turned to on, and again has power when the engine is cranked. You might miss the two second signal, so check for power when car won't start-when pump won't turn on-and with the engine cranking. If you have a signal then and still no pump coming on, then you must have a failing pump.
But if you have NO power to fuel pump wire with engine cranking, then it is a problem elsewhere-probably the pump relay (try a new relay if you haven't already). That relay is signaled by the engine computer when key is turned to on or when engine cranks . so you could do some testing at the relay if needed.
Here is the manual
FUEL PUMP SHUT-OFF SWITCH
After a collision, if the engine cranks but does not start, the fuel pump
shut-off switch may have been activated. The "Fuel Reset" indicator light
will illuminate in the instrument cluster. The shut-off switch is a device
intended to stop the electric fuel pump when your vehicle has been
involved in a substantial jolt.
1. Turn the ignition to the OFF position.
2. Check the fuel system for leaks.
3. If no fuel leak is apparent, reset the fuel pump shut-off switch by
pushing in the reset button.
4. Turn the ignition to the ON position. Pause for a few seconds and
return the key to the OFF position.
5. Make a further check for leaks in the fuel system.
The fuel pump shut-off switch is
located in the passenger's foot well,
behind the kick panel.
pumping the petal will not flood engine. Can u smell gas while trying to turn it over? can u pull a spark plug and smell fuel on it. You also do need to make sure you are getting fuel to the fuel rail first can u hear the pump come on when you turn key in the on position second with key on engine off see if fuel comes out of the port at the fuel rail careful contents under pressure.
3. have one person listen in the gas tank at the gas cap opening.
4. have the other person turn the ignition switch to the ON position ONLY so as the dash lights come on. Do NOT attempt to start the engine.
5. As soon as the ignition key is turned to the ON position, The person at the gas tank should hear the fuel pump run for TWO SECONDS and then it should STOP.
6. Does it ?.
If you do NOT hear it run, in most cases the fault is the fuel pump relay or the fuel pump..
As soon as you turn ON the ignition switch to start the engine a 2 second ONLY battery voltage signal is sent from the computer to the fuel pump relay and from the relay back to the fuel pump in the fuel tank. This runs the fuel pump for ONLY 2 seconds of which pressurizes the fuel system in preparation to start the engine.
Once the engine starts, The computer BYPASSES the fuel pump relay and sends constant contionous battery voltage from the computer to the oil pressure switch of which is now CLOSED because the oil pressure is UP because the engine is running. Therefore the battery voltage flows thru the oil pressure switch back to the fuel pump to run the fuel pump constantly until you turn OFF the engine.
Check to see if you have fuel and spark. If you have fuel and no spark, check your crank position sensor. I had one in my shop very similar to yours. When you turn the key to "on" position, do you hear the fuel pump come on? You should hear a hum for a couple of seconds.
×