Stupid question about fuel pumps

[Dan]

On my Cobra, the fuel pump would run for a certain time when I switched it on and then stop (I guess when a certain pressure was reached). Obviously once the engine was running , I could not hear the pump anymore, so I don‘t know whether it run continiously or not.

On my, new to me, SPF MK1, the fuel pump runs when I turn it on and never turns off, eben without the engine running.

Is this normal "behaviour"?

 

[Terry Oxandale]

There are different ways to set up a pump, and different pump designs. I would say your '40 set-up is pretty common, and in fact, much more common than what you had on your Cobra.

 

[JP Verweij]

it depends on which type and brand your fuelpumps are.

 

[Dr. Bob Woods]

My ECU turns the pump on for about 10 seconds and then turns it off until the starter has the engine turning about 500 rpm and then it turns on the pump again.

 

[Dan]

it depends on which type and brand your fuelpumps are.

Ok. SoI don’t need to worry about it

My ECU turns the pump on for about 10 seconds and then turns it off until the starter has the engine turning about 500 rpm and then it turns on the pump again.

No ECU, good old Webers for me with MSD ignition

 

[JP Verweij]

Ok. SoI don’t need to worry about it

I think you miss read my commend.....

 

[Dan]

I read it in the way that it can be normal. I will remove the hatch this weekend and check out which pumps are installed and report back.

 

[Dan]

So I have a Holley red pump. Is it normal for it to run continuously?

Also it is noisy as hell, the noise goes right through to the cabin. I can see that it is bolted directly to the rear wall of the sponsoon. Thinking about adding some rubber insulators to dampen the noise or should I build a « container » from EPDM foam to separate the rear part of tge sponsoon off and dampen the noise?

 

[Chris Kouba]

You're worried about fuel pump noise?

Just turn up your sound system and problem solved:

 

[JP Verweij]

So I have a Holley red pump. Is it normal for it to run continuously?

Also it is noisy as hell, the noise goes right through to the cabin.....

Yess & Yess.
Holley Red is a superb & durable fuel pump that delivers a great amound of GPH.
They run continuously and are very noisy.
Nothing to do about that beeing noisy, but when your engine fires up usualy you'll only hear exhaust rumble.

 

[Dan]

Well I was more worried about the pump running continiously. But now that I know that that‘s normal, I‘ll just put it on rubber mounts to get rid of the annoying whine, that I hear even when the engine is idling (not of course on wide open throttle). It‘s a $5 invest for a couple of rubber mounts, so it‘s not gonna bankrupt me ;-)

 

[Bill Kearley]

In most systems they run full time and meant to do so. It's not a problem. An inertia switch is a good idea.

 

[Dan]

In most systems they run full time and meant to do so. It's not a problem. An inertia switch is a good idea.

That‘s what I thought as well. So I will order one of those.