When this happens there are typically two common causes. Because fuel pumps constantly run whenever the ignition is turned on they can eventually wear out and weaken over time.
32 Gph Holley Mighty Mite Electric Fuel Pump 4 7 Psi
Fuel pump constantly running. Hello i have a 2008 sierra sle with a 53 engine. When i turn the truck off the fuel pump continues to run. Other google searches have made mention of a fuel pump flow control module but i have yet to find any posts that talk about it causing the fuel pump to run constantly even when the keys are out of the ignition. The only way i can get it. Therefore the purging process stops to allow the gas tank to be pressurized only a few psi of pressure and the sound went away. Gasoline needs air to burn.
A weak fuel pump may still pump fuel but the vehicle may experience difficulty starting from the lack of pressure. I swapped the ac compressor relay with the fuel pump relay in the fuse block but that did nothing. Keep in mind that the computer only runs the fuel pump for about 2 3 seconds when you turn. No its not the fuel pump thats running but the purging system. If the fuel pressure regulator is not maintaining exact fuel pressure while the engine is running it can cause the engine to run rich or lean and in the event it goes too far in either direction the engine will stall out due to an inability to properly burn the airfuel mixture. If it doesnt the wiring between pin 22 on the computer and the fuel pump relay is bad.
The key to the run position. I unplugged the oil pressure sensor the pump started running again once the positive was reconnected at the battery. I tried pulling the fuel pump fuse and it still kept running. When a well pump is running all the time and will not shut off the most common reason is that the well pump is not able to build enough pressure in the system to tell the pressure switch to turn the well pump off. The most common cause is a hole in the drop pipe down the well. The pump should run at full pressure.
When you turn the ignition on even without starting the engine that activates the fuel pump and also pressurized the tank. Another symptom commonly associated with a problematic fuel pump is difficulty starting. If it does run at full pressure the computer may have failed.
Gallery of Fuel Pump Constantly Running
