Fuel Pump Problem - Weird Priming Noises On Cold Start, Fine Once Warmed Up?

[Andi]

Hey all,

Have a small problem regarding the Bosch 040 pump since installed. On a cold start when I turn the key to reds/ignition the pump makes weird noises when priming. Instead of the usual buzzing/whirring it makes weird knock like noises, reminds me of my friends description of indigestion noises. It sounds like it works, stops, works, stops, works stop giving off a knocking noise.

The noise however doesn't occur anymore after you've driven the car for abit i.e after its actually warmed up. Once the car is warmed up it'd make a normal priming noise of a constant buzzing for a few seconds then just stop.

Any ideas of what this could be? I'm hoping direct feeding a 13.8v power source to the pump will solve this issue.

Oh and when I installed the pump I warpped the pump in a rubber layer so it wouldn't make any noises, could this potentially be causing the problem or another problem?

Thanks!

Andy

[R31Nismoid]

So when its cold... the car has been sitting overnight yea?

And when the car is warm, its been sitting for what... 5mins maybe?

[Andi]

Cold start = over night.

Warm = after cars been driven then turned off and back on again shortly after.

[tridentt150v]

Take it out and try running it in a bucket maybe???

Check everything and see if there is a reason?