Fuel pump fuse blows while driving...what happens?

[jimxms]

Theoretical question, if you were giving it some beans down the m/way and your fuel pump fuse blew, what would happen?

A) Car stalls and you coast to a stop.

B) Engine runs lean, melts stuff.

[MGJohn]

jimxms said:

Theoretical question, if you were giving it some beans down the m/way and your fuel pump fuse blew, what would happen?

A) Car stalls and you coast to a stop.

B) Engine runs lean, melts stuff.

Same as what usually happens when you run out of fuel .... coast to a stop.
.

[Purple Tom]

On most modern cars its likely to force the fuel pump relay to switch off which will also power down the ECU (often the FPR is a 5 or 6 pin jobby feeding the ECU and other stuff) so the car will just die.

On older non-EFI cars with an electric fuel pump then it'll behave exactly the same as if it just ran out of fuel, as in lose power and gradually die over the course of 10 seconds or so. No danger of it running lean as if it happened at high rpm it'd just use its remaining fuel supply more quickly.

[Futuramic]

jimxms said:

Theoretical question, if you were giving it some beans down the m/way and your fuel pump fuse blew, what would happen?

A) Car stalls and you coast to a stop.

B) Engine runs lean, melts stuff.

This actually happened to my old Volvo; except the lift pump itself seized as I was pulling on to a roundabout. It had mechanical (Bendix?) injection. The engine continued running for a few seconds but wound down. Opening the throttle had no effect. The car rolled to a stop. No damage caused whatsoever. New pump fitted and it burst into life once more.

[jimxms]

Cheers boys, just what I was hoping to hear

[RV8]

I suppose it depends on the vehicle. My LPG system is sucking through two large SU carbs, no fancy computer, old V8. When I switch the rocker switch I use up the petrol in the system from the shut off solenoid to the carbs. Depending on how much throttle I use after switching this can be around 30 seconds of driving. At the point where it runs out you can feel the drop in power and that is when you rock the switch over to LPG - now I'm running on GAS. You cant rock it instantly over as you'd be running rich (gas and petrol) Effectively the system is the same as an automatically controlled version but you are playing the part of the computer. I believe it'd be the same effect as running out of petrol/the pump stopping if you leave it switched in the cut off position too long and it'd just stop firing and cut out rapidly.