[humyum]

Originally Posted by SS-Traveller

Is there any reason why push starting can't be done in first, third or even fourth or fifth gear?

Push starting a car = you are not going to be pushing it REALLY fast. Without any help from the fuel igniting in the cylinders, 1st gear will slow the car down as soon as you let the clutch off because of the higher ratio. This duration till the clutch release to the vehicle stopping won't be enough to start the engine. 2nd gear is not too tall, not too short and hence 2nd gear.

If you are starting the car on a downslope and can attain a higher speed, yeah you can even use 3rd, 4th or whatever you like.

[aswin ajith]

Originally Posted by humyum

a push start

I am surprised many have mentioned about push starting. Is it not bad for the exhaust system? The catalytic convertor to be more specific. I am saying this because the owners manual of the Ritz P we have at home mentions so. Any thoughts on this ?

[humyum]

Originally Posted by aswin ajith

I am surprised many have mentioned about push starting. Is it not bad for the exhaust system? The catalytic convertor to be more specific. I am saying this because the owners manual of the Ritz P we have at home mentions so. Any thoughts on this ?

Its all right once in a bluemoon, no harm at all.

[SS-Traveller]

Originally Posted by humyum

Push starting a car = you are not going to be pushing it REALLY fast. Without any help from the fuel igniting in the cylinders, 1st gear will slow the car down as soon as you let the clutch off because of the higher ratio.

Is there a certain minimum engine cranking RPM that one needs to achieve for a particular engine before it will fire up? If so, what is that RPM for the GV engine?

[humyum]

Originally Posted by SS-Traveller

Is there a certain minimum engine cranking RPM that one needs to achieve for a particular engine before it will fire up? If so, what is that RPM for the GV engine?

I don't know for a GV but a petrol engine takes from anywhere 80 to 120 rpm's to start.

Are you trying to conclude something ? If yes, I am all ears

[SS-Traveller]

Originally Posted by humyum

I don't know for a GV but a petrol engine takes from anywhere 80 to 120 rpm's to start.

Are you trying to conclude something ? If yes, I am all ears

I thought you'd already drawn your conclusion. If a car can be pushed only at walking speed, which gear would achieve higher engine RPM?

[humyum]

Originally Posted by SS-Traveller

I thought you'd already drawn your conclusion. If a car can be pushed only at walking speed, which gear would achieve higher engine RPM?

Theoretically yes, practically the wheel would stall at walking speed in 1st gear if you let the clutch go as without any fuel to ignite the charge in the cylinders, the engine will not let you increase the engine rpm that quickly. unless of course you do manage to push it at a higher speed.

Secondly the theory about the starting rpm has a flaw when it comes to push starting. A starter motor runs for 1.5 to 2 seconds before your vehicle starts, while push starting, all you have is a momentary jerk to start the car. In 1st gear, the duration remains shorter and chances of a vehicle starting are lesser than in 2nd gear where due gradual rise (as compared to 1st gear) in engine rpm, the chances of the vehicle starting are higher.

Also there is not a complete loss of momentum if your vehicle does not start in while you are in 2nd gear, the people pushing the car can again push a vehicle which has a little momentum left for the push start to be tried again.

Let's agree to disagree man, I can't explain it more clearly than this.

[sudev]

@SST Can push start in any gear the idea is to release and press the clutch as soon as engine fire up. The reason for doing it in first (or second) is only to lessen jerks on drive train.

Try it and you will know.

@GTO - well said but in emergency and away from home jumper cables may not be handy.

I recommend all to get a one or two starts practice while things are normal so that you do not panic in emergency. In fact got my sons and daughter to learn this and wheel changing as art of initial car care.

[saket77]

Originally Posted by aswin ajith

I am surprised many have mentioned about push starting. Is it not bad for the exhaust system? The catalytic convertor to be more specific. I am saying this because the owners manual of the Ritz P we have at home mentions so. Any thoughts on this ?

Once in a rare while is okay.
And you should try to get the vehicle's engine running as soon as possible while push starting. If not, excess unburnt fuel can make its way to exhaust and catcon and damage the functioning of the precious metals inside. So, if the fault is something other than a failed starting motor or a dead battery which can prevent the vehicle from starting, it is best not to try push start as excess and unburnt fuel will eventually find its way to places where it should not, ideally.

[SS-Traveller]

Originally Posted by sudev

@SST Can push start in any gear the idea is to release and press the clutch as soon as engine fire up. The reason for doing it in first (or second) is only to lessen jerks on drive train.

Try it and you will know.

I know already... Hence the question!

Originally Posted by SS-Traveller

Is there any reason why push starting can't be done in first, third or even fourth or fifth gear?

[Jeroen]

Originally Posted by SS-Traveller

Is there a certain minimum engine cranking RPM that one needs to achieve for a particular engine before it will fire up? If so, what is that RPM for the GV engine?

Yes, not sure about this car, but typically the ECU needs to see a few rotations at a certain speed (through the crankshaft position sensor) before it will start. At least in theory it would need two rotations before it will start injecting fuel.


So I would say its likely to be a combination of a certain rpm in order to achieve certain compression and a couple of turns anyway before the electronics will allow it to start

Jeroen

[bejoy]

But will it start? Not my i10 at least. Tried all the tricks to get it push started but it would not budge. We three people pushed it really hard to reach atleast 30kmph and tried clutch dump in 2nd gear. This was tried multiple times and tried even cranking at the same time. Finally had to use another battery to start and hot swapped the battery to get going. So if you have a really drained battery (I had my parking light on for 10 hours) its mostly impossible to get it pushed start. Basically the fuel pump would not work meaning no pressure at all for injecting in fuel. So no more push start attempts by me!

[sudev]

Common sense is uncommon.

Battery dead + MPFI = No push will get it started.....maybe real long down hill ???!!!
Battery dead + Carb = Push start possible
Battery live + MPFI / Carb = Push will start
Battery live + No fuel = Hell will freeze over and you can keep pushing

...many more variations possible.

Manuals go out of the window when you are stranded and first priority is to get back to safety. Use this as a handy guide only for certain cases.

[zenren]

While we are on the topic of drained battery and push start, are there any dos and donts with respect to the source and destination of the jumper cables?

I have a petrol Swift with a new battery and a diesel Swift with a 3 year old battery, which should need a replacement some time in the next 1 year. If the diesel Swift fails to start one fine day due to weak battery, would it be okay to use the battery of the pertol Swift and jumper cables to start it? Diesel vehicles have a much higher capacity battery if I'm not wrong. Would this scenario work or would it end up draining the other battery too?

[a4anurag]

Originally Posted by zenren

If the diesel Swift fails to start one fine day due to weak battery, would it be okay to use the battery of the pertol Swift and jumper cables to start it? Diesel vehicles have a much higher capacity battery if I'm not wrong. Would this scenario work or would it end up draining the other battery too?

No issue's as both batteries are similar and all you would do is jump start it once or twice which will not have any issue on the Petrol Swift's battery.

Anurag.