Noisy Fuel Pump.... Bosch 044

[hulk xr6t]

Hi,

I have XR6T 300+ rwkw. Car has factory in tank fuel pump and a Bosch 044 fuel pump running in series. I do not have a surge tank. The Bosch 044 buzzes away which isnt the problem. (ive learnt to live with it)

But just recently its started running with a buzz and a stuttering sound. So im hearing a buzz and a da da da dadadada da......buzz.......da....da....da.dada.

Does this mean the pump isnt getting a good supply of fuel? is it working too hard? Is this normal and ok or is there a problem.

On the road the car goes fine. Only does it at idle. Has the odd miss here and there but on the road its sweet??? only at idle

Any ideas??

[gilto]

Mine did exactly the same thing....one day it just stopped making the noise and started humming as usual again.....never made the noise since.....

I put it down to something stuck in the pump perhaps?????? (but probably not)

Got no idea really.....the hum is hardly there now...it's very easy to live with....

[ETM]

the pump noise changes as the fuel supply changes.

when there is plenty of fuel for the pump to use the noise is at its quietest,if there is a break in the supply the pump will get much louder,the fuel is also what cools the pump which keeps it quieter aswell.

[hulk xr6t]

You would think it was sending out a morse code SOS signal this fuel pump. da da da dada da da.

Would a surge tank shut it up?

[ETM]

You would think it was sending out a morse code SOS signal this fuel pump. da da da dada da da.

Would a surge tank shut it up?

are you sure its not a bad earth or power supply?

[hulk xr6t]

Hmmm,

Hope not.. I had a professional install it. One of our sponsors so im pretty confident they would install it correctly...

At first it didnt make this noise, this is just recently..

[ETM]

in my opinion you are playing with fire without a surgetank,you have the 044 being supplied by a pump which cannot pump as much fuel as the 044 is pumping.

id like to see what a fuel pressure gauge would read on that line between the 2 pumps

in theory there is 2 possible answers to that question.

1. a vacuum,the 044 is moving more fuel than the stock one can give it resulting in negative pressure in the line. (I cant see that happening)

2.the 044 is being starved of fuel and is working overtime and hotter than it should

I would be investing in a surgetank and making sure its wired up with its own relay and its own 12v power supply.

[hulk xr6t]

in my opinion you are playing with fire without a surgetank,you have the 044 being supplied by a pump which cannot pump as much fuel as the 044 is pumping.

id like to see what a fuel pressure gauge would read on that line between the 2 pumps

in theory there is 2 possible answers to that question.

1. a vacuum,the 044 is moving more fuel than the stock one can give it resulting in negative pressure in the line. (I cant see that happening)

2.the 044 is being starved of fuel and is working overtime and hotter than it should

I would be investing in a surgetank and making sure its wired up with its own relay and its own 12v power supply.

The car is running 307rwkw. apparently the stock pump is good enough to supply that so why wouldnt it be able to supply the 044 at idle? The installer said if anything the 044 and fuel pump in the tank and helping one another. the 044 should be able to run alone and suck from the tank, but its being assisted. Likewise with the 044, sucking and helping the in tank pump push it out.

[ETM]

The car is running 307rwkw. apparently the stock pump is good enough to supply that so why wouldnt it be able to supply the 044 at idle? The installer said if anything the 044 and fuel pump in the tank and helping one another. the 044 should be able to run alone and suck from the tank, but its being assisted. Likewise with the 044, sucking and helping the in tank pump push it out.

the fuel pump cares not what power you are making or if the engine is at peak rpm or idle,it pumps the same amount of fuel regardless.

you can give me as many theories as you want but the facts are yours isnt working properly so you need to first eliminate the wiring as a problem,once that is cleared if the problem still exists it can only be the way the system is plumbed.