Hi All,
It's me again, this time with a question about the fuel pump control. I have been reading up a bit on this pump and it's various attachments ( Pressure regulator , relief valve etc ) and the operational method.
This pump seems to me to be a positive displacement pump and has to have a pressure relief valve on the discharge to protect it from wrecking itself if the discharge is blocked, fair enough. This relief is set about 5 bar ? But this shouldn't happen if the regulator controls the flow to the fuel rail to around 3 bar ?
When you switch on, the pump should run for about 3 secs to prime the system and the stops ( mine doesn't ) So when the correct pressure is reached to the injectors, what stops the pump ? ( engine not running ) Is the electrical supply to the pump interrupted by a pressure switch. If there isn't, then if the regulator is of the spill or dump type, the pump would still run at 3 bar with the regulator spilling back excess to the tank. Or have I got it all wrong ?
Cheers