is ECU controlling FUEL PUMP?

[evothinker5]

Well i changed the fuel pump now after it burned.. (i still dont know why) but now i have a question regarding power to fuel pump ---- is the ecu controlling the fuel pump? I mean i see two relays in the dash one of them is ignition and another i think is the fuel pump. when i try to start the car the ignition relay clicks but the other one... i dont hear anything... ( NOTE: I HAVE MY BATTERY ALMOST DEAD)

1.is the ECU controlling the fuel pump?
2.is the fuel pump running always with the engine on?

[glasgowjim]

When the ignition is switched on the fuel pump primes.
The second relay is for the fuel pump.

[evothinker5]

hey u didnt answer my question... (

[glasgowjim]

do you really need an answer to question2

[evothinker5]

u didnt even answer the first question

[Robou]

The first question can only be answered with knowledge of the specs of the car.
The second needs no answer unless you mean ignition switch on.

[jamesy12345]

Without knowing exact spec of your car, just using the search function, probably.............................

When the engine spins up to more than 45 rpm (yep, forty five), pin 17 of the LH 2.2 will ground and operate the fuel pump relay.

This information from here http://www.volvo-480-europe.org/forum/v ... =3&t=34017, so may be that this is B18FT engine only. Do you hear the pump priming when you turn the ignition on for the first time without operating the starter?

Wiring diagrams from here http://www.volvo-480-europe.org/volvo480/downloads.php

So, more than likely, yes the ECU controls the fuel pump and yes the fuel pump is running while the engine is running. Otherwise the engine would stop due to no fuel - usually only motorbikes etc have gravity fed systems.

[svenska axel]

could the relay be stuck on, hence no clicking and fuel pump burning from never turning off. not too hard to open a relay box and look whats happening.