How long does it take to prime a fuel pump?
Between 5 minutes and 50 hours. A fuel pump on an old lawn mower is on the low end, a fuel pump on a Stealth Fighter would be on the higher end. See how specifics matter? More than likely, you're talking about a car, but year, make, model, and trim can make a very large difference.
Quick and easy way to check if your fuel pump is working - YouTube
It's safe to say that replacing a fuel pump is not fun. It takes about two to three hours to complete the job. Depending on your make and model of vehicle, it can be quite a challenge. If you're not confident in changing it yourself, it's best to take it to a mechanic.
The most common cause of the fuel system not holding pressure up to the injectors is the fuel pump inside the fuel tank. The fuel pump has a check valve built into it that is supposed to keep pressure to the injection system when you shut down and vehicle sits.
After refilling your gas tank, try turning the key to the "On" position (turning on the electronics without cranking the engine) and then back to "Off" a couple of times to prime the fuel pump. Priming the fuel pump will help remove air that may have entered the fuel lines as a result of running out of gas.
However, replacing a car's complete fuel assembly and dropping the fuel tank will take between 2 and 3 hours. So, a fuel pump is not expected to take the whole day before working.
If the fuel pump is not coming on, and the fuse and relay are good, then it may be possible that there is a problem with the pump or the fuel pump circuit. The first thing I would do is check to make sure that there is power to the fuel pump circuit, and that the relay is in fact sending power to the pump.
Fuel Pump Electrical Check - Wrenchin' Up Back To Basics
- Engine runs poorly. If you've owned your vehicle for several years or have experience behind the wheel in general, you probably know what a well-running engine sounds like. ...
- Vehicle doesn't start. ...
- Overheating engine. ...
- Can't sustain speed. ...
- Decreased fuel efficiency.
How to Properly Test and Diagnose a Bad Fuel Pump - YouTube
Does a fuel pump need to be primed?
That pressure pushes fuel very quickly. In contrast, the fuel pressure created by mechanical fuel pumps is much less, usually in the 1–4 psi range. Second, this is important because the fuel system needs to be primed—the lines between the tank and the engine have to be filled with fuel.
- Fill the fuel tank.
- Turn the ignition key to the ON position.
- Move the engine stop/run switch to the RUN position.
- Allow the fuel pump to run until it stops (about 2 seconds).
- Move the engine stop/run switch to the STOP position.
- Repeat steps 3–5 four to five times.
...
Should your vehicle shut off after a crash, you may restart your vehicle:
- Switch off the ignition.
- Switch to start position.
- Switch off the ignition.
- Switch on the ignition to re-enable the fuel pump.
- If vehicle does not start, repeat steps 1 through 4.
Critical components, like your vehicle's fuel pump, aren't designed to operate without fuel. And while it's unlikely you'll cause immediate damage by running out of gas once or twice, you can reduce the lifespan of these parts — leading to costly repairs later.
Fuel Pump Electrical Check - Wrenchin' Up Back To Basics
THIS REALLY WORKS!!!!!!! Bad fuel pump, fuel pump relay ... - YouTube