6 replies to this topic

[Classicmini63]

Fitted a complete pump unit on my MPI. Fuel pressure problem is solved and runs a lot smoother. Only problem is now and again I’ll start it up and instead of being quiet to the point of almost not hearing it, it’s really loud? So I’ll turn the engine off, start it again and then it will be quiet like normal?

It first did it yesterday just after I’d fitted the pump, took it round the block and it was still making the same loud noise. Stopped, turned engine off and then back on, and the noise was gone.

It didn’t make the loud noise when it first started it up, but it did on maybe the 3rd run round the block.

Any ideas what this is?
Cheers

[Bat]

Hi,

They usually get louder the harder they have to work.

Have you changed the fuel filter in the subframe?

Cheers 

[Classicmini63]

Hi, I usually change it every 6 months but not completely sure as to how often to change it? I’ll defintiely change it this week as we’re off to MITP this weekend so full service will be in order. I’ll see how it goes with a new filter.

Cheers :)

[Bat]

Hi,

2 years or 24,000 mls according to Mini Spares I think.

Cheers 

[Classicmini63]

Oh right!! Mine probably does 240 a year??

[Alice Dooper]

The pump will make a louder noise for a few seconds the first time in he car is started, it’s working hard to raise money he fuel pressure at the fuel rail for the injectors. Once it has reached pressure, the pump cuts out until the starting circuit and then the normal running circuit energise the pump again. If you stop the car, it will retain the pressure at the fuel rail for a short time, so the pump isn’t triggered into loudly pressurising up again,

They can be noisy when having to work hard and with the fuel tank acting like a big sound amplifying box and it being inside the car it. Can seem very noisy.

It would be worth changing the fuel filter wit a new pump going in anyway, small bits of dirt can be agitated back into circulation with all the work when you were putting in the new pump. Dirt will kill a pump pretty quickly.

[Steve220]

The pump will make a louder noise for a few seconds the first time in he car is started, it’s working hard to raise money he fuel pressure at the fuel rail for the injectors. Once it has reached pressure, the pump cuts out until the starting circuit and then the normal running circuit energise the pump again. If you stop the car, it will retain the pressure at the fuel rail for a short time, so the pump isn’t triggered into loudly pressurising up again,

They can be noisy when having to work hard and with the fuel tank acting like a big sound amplifying box and it being inside the car it. Can seem very noisy.

It would be worth changing the fuel filter wit a new pump going in anyway, small bits of dirt can be agitated back into circulation with all the work when you were putting in the new pump. Dirt will kill a pump pretty quickly.

 

There is no fuel pressure sensor in the system, its designed to fire the fuel pump for 5 seconds prior to crank.

 

I wouldn't worry about it unless you're having running problems. The other option is to run more sound deadening around the tank.