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Old 14th March 2006, 16:17   #1
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Does the fuel pump run even when engine is off, but key in ON position ?

Guys, have a query about functioning of the fuel pump in Baleno.

I got a leaflet recently from Maruti giving quite some useful information on effective use of the a/c, good driving practices and ways to improve fuel efficiency (FE). One of the tips mentioned in the leaflet to improve FE was to avoid idling the car if the wait is 60 seconds or more - for eg. at a traffic light with timer. I have been using this method of fuel conservation for donkeys years on my M800 and so naturally continued the same on the Baleno also.

The M800 did not have an AC and I would drive with windows down. However, with the Baleno, I prefer to always use the a/c, esp. with the Chennai weather being what it is. So, at a traffic light, I switch off the car, but keep the ignition in the ON position so that the blower can work - otherwise it will become real hot inside.

I read somewhere on tbhp that if I keep the key in ON position, it will cause the fuel pump to run continously which can be bad for the pump.
I would like to know if this information is true. If so, then I guess this particular way of fuel conservation cannot be used when driving with AC.

Last edited by supremeBaleno : 14th March 2006 at 16:19.
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Old 14th March 2006, 21:28   #2
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when you switch the ignition on, the fuel pump situated inside the fuel tank starts pumping fuel to the engine. so yes, it DOES run even when the engine is off, when the ignition is on. but this does not translate into fuel wastage. so, if you are stopping at a traffic light for more than 60 seconds, it's okay to cut off the engine and keep the ignition on, but not for long, i.e more than 2 minutes or so everytime. if the car is being used under constant stop and go conditions, it's better to either keep the engine running, OR roll the windows down and switch off the ignition and the blower too.

if want to have your cake and eat it, (run the blower while saving the fuel pump's life) what you can do is this; if you have a lxi, tell your maruti dealer to rewire and enable the blower at the "OFF" position, rather than the "ON" or "IGNITION" position. if it's a vxi, the wiring could be slightly more complicated due to the climatronic a/c.
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Old 14th March 2006, 22:45   #3
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Quote:
Originally Posted by veyron1
if want to have your cake and eat it, (run the blower while saving the fuel pump's life) what you can do is this; if you have a lxi, tell your maruti dealer to rewire and enable the blower at the "OFF" position, rather than the "ON" or "IGNITION" position. if it's a vxi, the wiring could be slightly more complicated due to the climatronic a/c.
The blower already works in ignition ON position. But the A/C compressor doesnt. I have heard that in Indica, you can have A/C switched on without having the engine idling (ignition position) ?!
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Old 14th March 2006, 23:27   #4
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@Dceite; the blower (in almost all petrols) now works in the "ON" position; it's obvious that the compressor works only when the engine is running; but the electromagnetic clutch of the compressor can be engaged (which is what happens when you switch on the compressor switch), even when the engine is off. the engine is not required to run for the compressor clutch to engage.

the final position of the key, where the steering is locked and the key removed, is the "LOCK" position. the first turn, is the "OFF" position, where the key can't be removed, but the steering is unlocked. then comes the "ON" or "IGNITION" position, after which you turn the key for activating the starter, to crank the engine (actually, the "ON" position isn't the "IGNITION" position. it's a misnomer. the actual "IGNITION" is when you turn the key to crank the starter) . diesel cars have another position of the key instead the "OFF" position, called "ACCESSORY" or "ACC" position. in this position, all electricals including the blower can be used, without going into the "ON" position (where the heater - for IDI engines; ECU control and fuel pump/injector timing for CRDi - is activated).

thus, in the indica, the blower can be used without turning the key to the "ON" position, i.e, in the "ACC" position. but, the A/C can't be used, as no compressor will run without the engine.

what i was suggesting, was to get the blower controls of the baleno wired to the "OFF" position, right after you unlock the steering. one of the ways to do that, (in a novice way) is to directly give the supply to the battery, where the blower will work even without any key..!! BUT, the disadvantages are;
a) you'll lose warranty,
b) you have to always check for the blower controls before you leave the car; if you leave it on overnight by mistake, your battery will be dead by the next morning.
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Old 15th March 2006, 02:14   #5
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Quote:
Originally Posted by veyron1
b) you have to always check for the blower controls before you leave the car; if you leave it on overnight by mistake, your battery will be dead by the next morning.
The OFF or the ACC position is the next to the lock position...right.
The 'stereo' and the 'lighter' work in the ACC position, BUT can you leave your stereo on without key?.... similarly you won't be able to leave your blower on if u remove the key.... i.e. no danger of battery drain.

Ok other than that.. if your car has central locking it would unlock all doors at the ACC position..... (you will have to manually lock without using the remote - else you'll have to unlock too using the remote)

Also... see the flip side of saving that tiny bit of fuel.
1) Excessive wear of central locking door lock guns.
2) Excessive wear of starter motor... (Seen that on my Alto Vxi)
3) Straining your fuel pump to build up pressure every time you switch off and on.
4) Your music system loses power while the engine starts... (Consider your system rotating a CD and you suddenly cut the power source - never good for electronics)
5) Starting the engine actually takes much more fuel than idling.

and maybe many more.....

idling actually takes very little fuel unless the a/c is ON.

My take is... only switch off... if you have to wait for 3+mins....

Maruti's fuel saving tips... are totally useless.... they damage the engine more than save fuel...
BUT they know the Indian customer is mad about fuel economy.... so they do everything to deliver that.....

1) 145 tyres on its small cars... (its skittish as hell)
2) 165 tyres on Baleno??? .. (its a bloody safety Hazzard)
3) Change to 5th gear @ 40km/h.... (the engine vibrates... begs for mercy... specially if you have a/c)

To add to that ... I get ANY (10-16.5 in city) fuel economy I want from my WagonR just by changing driving style... NOT SWITCHING OFF AT ALL... and driving in the rpm band where engine feels comfy.

I remember reading somewhere, ACI or OD… that WagonR takes less than 1/3rd of a litter of fuel for 1 HOUR of idling.

Then for 1 min of saving you get 72 meters of driving!! (assuming a FE of 13km/l)

Also see it this way… to save one litter i.e. (13kms of travel) .. I got to save 3 hrs of idling. AND if your avg saving time is 1 min…. you start your car 180 times. I wonder if its worth it!!!

Points to note
1) this was the wagonR, 1061cc engine… considered one of the cleanest in the world. Other cars might have slightly more idling consumption.
2) Car should be idling perfectly…
3) should be tuned perfectly…. (almost 0 emissions)
4) Don’t use a/c while idling … (takes a lot of fuel)
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Old 15th March 2006, 11:54   #6
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Quote:
Originally Posted by SLK
The OFF or the ACC position is the next to the lock position...right.
The 'stereo' and the 'lighter' work in the ACC position, BUT can you leave your stereo on without key?.... similarly you won't be able to leave your blower on if u remove the key.... i.e. no danger of battery drain.
i would urge you to read my post again carefully, friend. i said, you'll have to check the blower IF you rewire the controls to DIRECTLY RUN FROM THE BATTERY-NO KEY INVOLVED. also, in petrols, only the cig. lighter and the stereo works in the "OFF" position. in diesels, in the "ACC" or "OFF" position, you can also operate the power windows and blower too.

as for the central locking- no, if it's nippon's MGA, (supplied O.E with vxi) then the doors unlock only after you remove the key, not in the "OFF" position.

it's a misconception that you lose more fuel while starting than idling. it's actually the other way around.
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Old 15th March 2006, 15:03   #7
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Quote:
Originally Posted by veyron1
when you switch the ignition on, the fuel pump situated inside the fuel tank starts pumping fuel to the engine. so yes, it DOES run even when the engine is off, when the ignition is on. but this does not translate into fuel wastage. so, if you are stopping at a traffic light for more than 60 seconds, it's okay to cut off the engine and keep the ignition on, but not for long, i.e more than 2 minutes or so everytime. if the car is being used under constant stop and go conditions, it's better to either keep the engine running, OR roll the windows down and switch off the ignition and the blower too.

if want to have your cake and eat it, (run the blower while saving the fuel pump's life) what you can do is this; if you have a lxi, tell your maruti dealer to rewire and enable the blower at the "OFF" position, rather than the "ON" or "IGNITION" position. if it's a vxi, the wiring could be slightly more complicated due to the climatronic a/c.
Thanks, veyron1 for the clarification. And yes, I would like to have my cake and eat it too. Currently, the key positions are LOCK, ACC, ON and START - the Blower is enabled at the ON position. I would get the dealer to rewire my Lxi to enable the blower at ACC position. That should solve the problem.
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Old 15th March 2006, 15:11   #8
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Quote:
Originally Posted by SLK
Also... see the flip side of saving that tiny bit of fuel.
1) Excessive wear of central locking door lock guns.
2) Excessive wear of starter motor... (Seen that on my Alto Vxi)
3) Straining your fuel pump to build up pressure every time you switch off and on.
4) Your music system loses power while the engine starts... (Consider your system rotating a CD and you suddenly cut the power source - never good for electronics)
5) Starting the engine actually takes much more fuel than idling.
and maybe many more.....
I understand the points raised by you, SLK. But, if there is a practical way of saving any non-replenishable resource, I prefer to use that.

Quote:
Originally Posted by SLK
I get ANY (10-16.5 in city) fuel economy I want from my WagonR just by changing driving style...
Hey SLK, is the 16.5 kmpl figure with AC on ? And which city ? That is great FE, man. I had heard of some nice FE figures on the WagonR, but this is real good.
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Old 15th March 2006, 20:15   #9
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Quote:
Originally Posted by veyron1
i would urge you to read my post again carefully, friend. i said, you'll have to check the blower IF you rewire the controls to DIRECTLY RUN FROM THE BATTERY-NO KEY INVOLVED.
Ya, I get it, sorry for that...

Quote:
Originally Posted by supremeBaleno
Hey SLK, is the 16.5 kmpl figure with AC on ? And which city ? That is great FE, man. I had heard of some nice FE figures on the WagonR, but this is real good.
no 16.5 is witout a/c..... the minimum witout a/c for me would be about 11km/l.
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Old 16th March 2006, 10:25   #10
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Quote:
Originally Posted by supremeBaleno
Guys, have a query about functioning of the fuel pump in Baleno.

.............................

If so, then I guess this particular way of fuel conservation cannot be used when driving with AC.
Dude fuel pump lasts like 150,000 KM
I am against switching car off at singnal for other reasons.
But in your case, you will be using more fuel.
What is happening is
  • You put on AC
  • Cabin gets cooled
  • You switch off AC at signal
  • Cabin starts to heat up
  • Again you put on AC to cool cabin

If I was in your place I would worry more about compressor than fuel pump.

PS: Remember those leaflets/manuals are written by lawyers not engineers & for ideal world conditions.
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Old 16th March 2006, 11:38   #11
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Quote:
Originally Posted by dceite
The blower already works in ignition ON position. But the A/C compressor doesnt. I have heard that in Indica, you can have A/C switched on without having the engine idling (ignition position) ?!
No you dont. Thats a misconception. Do this. keep the key to on position(engine off). Switch on fan, and press AC switch. You will hear a new sound. thats not the AC, thats the AC condenser fan which switches on. The AC compressor works only when Engine is on.
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Old 19th May 2006, 10:37   #12
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Just to update this thread with some info that I got regarding the min time duration when it is worthwhile to shut down the engine when stationary (instead of letting the engine idle). MUL says if the wait is 1 min or more, cut the engine to save fuel. Some members mentioned that it would be useless because starting the engine would consume more fuel than what it would have used if it were instead idling.
I happened to come across this list of FE enhancing tips by JD Power, which mentions "Because it takes very little fuel to start a warm engine, turn off the motor if you will be waiting while parked for more than one minute." Now with most places in India having traffic lights with timers, I guess it would be possible to follow this practice. But then, as someone mentioned here, this would be a bad practice to follow in stop-and-go traffic and might result in harm rather than good - not just to the FE, but compresser, ICE, fuel pump etc.
The complete list of FE enhancing techniques is available at
http://consumercenter.jdpower.com/cc...?id=129&page=1
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Old 11th October 2007, 12:52   #13
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I dont think that the fuel pump remains on when the engine is off in carburetor vehicles. This would flood the carburetor.
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Old 20th January 2008, 09:24   #14
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Reviving the thread.

When you turn the key to the ON position, in modern MPFI cars, engine-check light comes on and you hear a sound (fuel pump) and it stops in about 1-2 secs. It is advised that you start the vehicle after this process, right? I do not think the fuel pump keeps pumping fuel when key is in ON position.
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Old 20th January 2008, 12:10   #15
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it depends on vehicle, like iKON and Crv the pump cuts off after few sec, swift D it doesnt
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