Does the fuel pump run even when engine is off, but key in ON position ?

Mpower · 20th January 2008, 19:33

when you are at a light keep it in ACC. In ON mode you will have more current draw.

hyper123 · 20th January 2008, 22:02

Quote:

Originally Posted by Mpower

when you are at a light keep it in ACC. In ON mode you will have more current draw.

Ok. Does this apply to indian carburetted bikes too (regarding the amount of current drawn)? Since they run on carbs, there will be no wastage of fuel I presume.

Ofcourse, there is no ACC position in bikes.

rks · 20th January 2008, 22:16

My Santro manual clearly states that the ACC position should be used. Keeping ignition on can damage the electrical components.

vnabhi · 21st January 2008, 12:10

I'm thoroughly confused after reading this thread. What I do is to switch off the engine if the wait is for longer than a minute (in winter, when I do not use the AC much).
In summers, I do not switch off unless the wait is for longer than 90 seconds, when I travel alone. With family, I don't switch off as they complain of losing the AC effect.

anandpadhye · 21st January 2008, 16:25

In my NHC, when I move my key to the Ignition position (but don't actually start the car), I hear the fuel pump humm for 3 seconds and then it shuts off.

So nothing to worry. Modern days ECU's manage things very well.

Jaggu · 21st January 2008, 18:17

Quote:

Originally Posted by vnabhi

I'm thoroughly confused after reading this thread. What I do is to switch off the engine if the wait is for longer than a minute (in winter, when I do not use the AC much).
In summers, I do not switch off unless the wait is for longer than 90 seconds, when I travel alone. With family, I don't switch off as they complain of losing the AC effect.

You are doing it correct, dont be confused

mail4ajo · 21st January 2008, 19:12

Quote:

Originally Posted by anandpadhye

In my NHC, when I move my key to the Ignition position (but don't actually start the car), I hear the fuel pump humm for 3 seconds and then it shuts off.
So nothing to worry. Modern days ECU's manage things very well.

Thats the pump priming sound. The pump fills its casing with fuel before its ready to start pumping so there is no lag in fuel delivery. I usually start after the sound stops.

I do not think the fuel is injected before the engine is cranked. So no chance for fuel wastage or overflow like in a Carb vehicle.

hyper123 · 21st January 2008, 19:41

Quote:

Originally Posted by mail4ajo

I do not think the fuel is injected before the engine is cranked. So no chance for fuel wastage or overflow like in a Carb vehicle.

I did not quite understand that part. How does fuel wastage occur in carb vehicles?

mail4ajo · 21st January 2008, 20:39

Quote:

Originally Posted by hyper123

I did not quite understand that part. How does fuel wastage occur in carb vehicles?

I have seen fuel dripping out my RX-100 carb maybe due to a faulty float. I had kept the fuel "on" overnight. It has a tube that lets out fuel. Not sure if this happens in cars.

Jaggu · 21st January 2008, 20:59

It "can" happen if carbs are out of shape/tune, and the phenomenon is called flooding. Can be observed by petrol leak around the packing area / wetness inside the butterfly area. But generally if all well, shouldnt flood even if you leave the ignition ON for sometime. Especially since carb cars also have a return circuit which will divert back the excess fuel to tank.

You can quote the above as one of the advantages of moving to Fuel injected system

since the whole system is leak proof to a great extend.

mail4ajo · 21st January 2008, 21:13

Quote:

Originally Posted by Jaggu

It "can" happen if carbs are out of shape/tune, and the phenomenon is called flooding.

I think in my case, the floats would have worn out and caused the flooding and ultimately draining out. Never bothered to change the float. Petrol was cheap at that time....

Jaggu · 21st January 2008, 21:46

hey if its bike (and you still have it), just clean the carb, dust and grime on the float pin can cause overflow, and even replacing float pin is a simple and cheap job

hyper123 · 22nd January 2008, 10:57

Ah, ok got it. I always shut off the pet cock whenever I park, so no problems.

Absar · 22nd January 2008, 17:12

Depends from car to car. Like in the rocam, the pump starts and shuts off after a few seconds. No damage here,but in newer engines like the DDiS,the pump sound doesn't stop somehow. On carb vehicles,the fuel pump would be running and running,hence leading to flooding.

cya
A

Jaggu · 22nd January 2008, 20:17

i think there are things like the pressure that needs to be maintained and more which govern the actual reasoning wrt cut off

20th January 2008, 19:33	#16
Mpower Senior - BHPian Join Date: Mar 2005 Location: Bangalore Posts: 10,399 Thanked: 1,735 Times View My Garage	when you are at a light keep it in ACC. In ON mode you will have more current draw.
	() Thanks

20th January 2008, 22:16	#18
rks BANNED Join Date: Nov 2005 Location: ?? Posts: 1,237 Thanked: 19 Times	My Santro manual clearly states that the ACC position should be used. Keeping ignition on can damage the electrical components.
	() Thanks

21st January 2008, 12:10	#19
vnabhi Senior - BHPian Join Date: May 2007 Location: DC -> DC Posts: 5,999 Thanked: 2,429 Times View My Garage	I'm thoroughly confused after reading this thread. What I do is to switch off the engine if the wait is for longer than a minute (in winter, when I do not use the AC much). In summers, I do not switch off unless the wait is for longer than 90 seconds, when I travel alone. With family, I don't switch off as they complain of losing the AC effect.
	() Thanks

21st January 2008, 16:25	#20
anandpadhye Distinguished - BHPian Join Date: Apr 2007 Location: Pune Posts: 3,060 Thanked: 3,347 Times	In my NHC, when I move my key to the Ignition position (but don't actually start the car), I hear the fuel pump humm for 3 seconds and then it shuts off. So nothing to worry. Modern days ECU's manage things very well.
	() Thanks

21st January 2008, 20:59	#25
Jaggu Team-BHP Support Join Date: May 2004 Location: Bangalore Posts: 20,384 Thanked: 17,299 Times	It "can" happen if carbs are out of shape/tune, and the phenomenon is called flooding. Can be observed by petrol leak around the packing area / wetness inside the butterfly area. But generally if all well, shouldnt flood even if you leave the ignition ON for sometime. Especially since carb cars also have a return circuit which will divert back the excess fuel to tank. You can quote the above as one of the advantages of moving to Fuel injected system since the whole system is leak proof to a great extend.
	() Thanks

21st January 2008, 21:46	#27
Jaggu Team-BHP Support Join Date: May 2004 Location: Bangalore Posts: 20,384 Thanked: 17,299 Times	hey if its bike (and you still have it), just clean the carb, dust and grime on the float pin can cause overflow, and even replacing float pin is a simple and cheap job
	() Thanks

22nd January 2008, 10:57	#28
hyper123 BHPian Join Date: Jan 2005 Location: Bangalore Posts: 321 Thanked: 2 Times View My Garage	Ah, ok got it. I always shut off the pet cock whenever I park, so no problems.
	() Thanks

22nd January 2008, 17:12	#29
Absar BHPian Join Date: Feb 2007 Location: Madras Posts: 560 Thanked: 10 Times View My Garage	Depends from car to car. Like in the rocam, the pump starts and shuts off after a few seconds. No damage here,but in newer engines like the DDiS,the pump sound doesn't stop somehow. On carb vehicles,the fuel pump would be running and running,hence leading to flooding. cya A
	() Thanks

22nd January 2008, 20:17	#30
Jaggu Team-BHP Support Join Date: May 2004 Location: Bangalore Posts: 20,384 Thanked: 17,299 Times	i think there are things like the pressure that needs to be maintained and more which govern the actual reasoning wrt cut off
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