My daughter's car, a Honda Jazz, have not been used for more than 3 weeks. We replaced a new battery as the engine failed to start. Even with new battery, the engine still failed to crank. We took it the workshop and was informed that the fuel pump has seized. Why does the fuel pump seized?

  • Because of the immutable law of things that if it is designed to move it will eventually stop. – Solar Mike May 11 at 4:43

There are unlimited possibilities to why fuel pumps seize.
Could be faulty
Could be old
Could have just "been its time to go"

I'm sure you're looking for a better explanation than that so here's my attempt. Usually it just gets dirt or sediment in it.

When a car sits for a while or when it runs completely out of fuel is when the fuel pumps seize. Gas is dirty and over time that dirt builds up at the bottom of your tank. The fuel pump eventually sucks up enough of that dirt to cause it to not work.

Some fuel is cleaner than others (as in not as much dirt mixed in) but is more expensive.

A way you can tell if your fuel pump is bad is to turn the ignition key to ON and listen for a little hum coming from the rear of the vehicle. You might need to have someone back there to listen. (Fuel pumps are usually inside the tank).
What's happening is when you turn the key the pump starts and attempts to "prime" the engine before it's started. This should make an audible noise for about a second or two.
If you don't hear it, turn the key to off then back to the on position again. If you still can't hear anything it could be that the pump is bad.

I hope this helps. Sorry if it's hard to follow.

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  • Have you come across mechanical fuel pumps? – Solar Mike May 11 at 10:49
  • Apologies, I assumed it was a vehicle from this or last decade ha-ha. Just disconnect a fuel line and attempt to crank the vehicle. Weak or no stream = bad fuel pump or clogged filter, but the filter is attached to the fuel pump so might as well... – Jay M May 11 at 10:59
  • I have seen a mech fuel pump “suck” a fuel tank flat... – Solar Mike May 11 at 11:31

If you think it is the fuel pump and there is not enough gas getting to the engine you can shoot some brake clean or starter fluid into the air intake and try starting it. If it starts it is not getting enough fuel.

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