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Old 29th August 2007, 12:05   #1
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Smile First gear clutch release operation in MPFI cars - clarification needed!

Hi techies,

I've been used to the carb cars of the past decade, where I step on the accelerator pedal while the clutch is half released when moving the car from a dead stop in the first gear. I've been instructed that in MPFI cars, after engaging the first gear, the clutch must be fully released before u step on the accelerator pedal. Habits die hard, as they say, I still have the habit of stepping on the gas pedal, in my new car, before the clutch is released fully in the first gear.

I'm curious to know whether this will damage the clutch/gear or both. Your suggestions are appreciated. Thanks in advance!

cheers,
giga
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Old 29th August 2007, 12:53   #2
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I learnt that here about my new Swift!

At first I couldn't believe it, so I tried, release clutch slowly with no gas... car moved off nicely.

Then I wondered how far I could push it and tried it on an incline: car stalled!

So, the car will move off on the flat without gas pedal, but I don't think there is any such thing as must release the clutch before applying gas.

If you are not over-revving the engine, or releasing the clutch too slowly giving too much slip, I'm sure everything will be fine.

We have a finely-tuned feedback system between our ears listening to engine sound, observation of the car movement, application of the feet. We use it for every gear change, but starting, especially on a hill, is the most critical. It is probably capable of taking more samples and making more adjustments than ABS does during an emergency stop!

We have to add a little more fine-tuning for each new car we drive and make adjustments, but after a day or two it is automatic to us.

If it feels right and sounds right, it is right --- and will do no harm.
If it sounds right and feels right ---it is right!

That's my theory, anyway
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Old 29th August 2007, 13:01   #3
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I agree with Thad in toto.
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Old 29th August 2007, 13:54   #4
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I use this to my advantage in cold starts. Here is what I do:

1) Crank the engine when cold. RPM is about 1200.
2) Release the clutch without using the accelerator and car begins to roll.
3) Engage second gear and the car keeps rolling at the same rpm.
4) Engage third with same results and after about 2-3 mins of driving this way I step on gas. Helps quite a lot in getting better FE.
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Old 29th August 2007, 14:01   #5
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Without stepping on the gas, are you sure that you are able to reach 3rd gear ?

Wonder if this is right for the engines health !

Ram P

Quote:
Originally Posted by moralfibre View Post
I use this to my advantage in cold starts. Here is what I do:

1) Crank the engine when cold. RPM is about 1200.
2) Release the clutch without using the accelerator and car begins to roll.
3) Engage second gear and the car keeps rolling at the same rpm.
4) Engage third with same results and after about 2-3 mins of driving this way I step on gas. Helps quite a lot in getting better FE.
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Old 29th August 2007, 14:08   #6
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Quote:
Originally Posted by moralfibre View Post
I use this to my advantage in cold starts. Here is what I do:

1) Crank the engine when cold. RPM is about 1200.
2) Release the clutch without using the accelerator and car begins to roll.
3) Engage second gear and the car keeps rolling at the same rpm.
4) Engage third with same results and after about 2-3 mins of driving this way I step on gas. Helps quite a lot in getting better FE.

may be i'm not too good with this, as I learnt driving on a 118NE, but how do u manage to do that? you live up a hill?
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Old 29th August 2007, 14:33   #7
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Newer knew this at all. Is the Lancer an MPFI?
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Old 29th August 2007, 14:34   #8
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Quote:
Originally Posted by moralfibre View Post
I use this to my advantage in cold starts. Here is what I do:

1) Crank the engine when cold. RPM is about 1200.
2) Release the clutch without using the accelerator and car begins to roll.
3) Engage second gear and the car keeps rolling at the same rpm.
4) Engage third with same results and after about 2-3 mins of driving this way I step on gas. Helps quite a lot in getting better FE.
As far as I remember, in the owners manual of my car it is written to start off when the temp needle reaches C. I may be wrong but isnt starting immediately after cranking bad for the engine?
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Old 29th August 2007, 15:17   #9
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i guess you are talking about idling car before starting to move ? thats a bad practice acc to car manuals and a lot of people these days. start the car and get it moving immediately but dont rev the engine or drive hard till it all warms up .

idling only wastes fuel.
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Old 29th August 2007, 15:39   #10
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Quote:
Originally Posted by bottle View Post
i guess you are talking about idling car before starting to move ? thats a bad practice acc to car manuals and a lot of people these days. start the car and get it moving immediately but dont rev the engine or drive hard till it all warms up .

idling only wastes fuel.
Completely agree. idling is bad, and it is the least efficient way of reaching the optimum running temperature. it is better to switch off and restart if u expect the idling to be more than 60 seconds - say waiting at a signal. however, idling is recommended before switching off a turbo engine esp the petrol turbos (not sure if it is still true for modern turbos).

MPFI/ECU,etc. control the fuel supply,etc. to the engine. And in drive-by-wire technology, the throttle input is sometimes just ignored! Clutch is just for connecting the transmission and the engine flywheel. You just have to keep the relative velocity between the flywheel and the clutch plate low irrespective of the nature of the engine.
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Old 29th August 2007, 15:47   #11
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Quote:
Originally Posted by lambuhere1 View Post
Without stepping on the gas, are you sure that you are able to reach 3rd gear ?
Wonder if this is right for the engines health !
What harm can you think of for the engines health?

Quote:
Originally Posted by gbpscars View Post
may be i'm not too good with this, as I learnt driving on a 118NE, but how do u manage to do that? you live up a hill?
It works on plain flat ground and I have tried this in first gear while going a slope. Did you read "I do this in cold starts"

Quote:
Originally Posted by BlackPearl View Post
As far as I remember, in the owners manual of my car it is written to start off when the temp needle reaches C. I may be wrong but isnt starting immediately after cranking bad for the engine?
My cars owners manual asks me not to waste fuel in idling. Roll the car as soon as you start it.

Quote:
i guess you are talking about idling car before starting to move ? thats a bad practice acc to car manuals and a lot of people these days. start the car and get it moving immediately but dont rev the engine or drive hard till it all warms up .
idling only wastes fuel.
Was it for me bottle?

Btw, the did you know that using the torque in the Palio Diesel 1.9D you can shift all 5 gears at idle and the car doesn't knock but pulls at about 45-50 kmph at 800-850 rpm
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Old 29th August 2007, 15:49   #12
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Quote:
Originally Posted by androdev View Post
And in drive-by-wire technology, the throttle input is sometimes just ignored! Clutch is just for connecting the transmission and the engine flywheel. You just have to keep the relative velocity between the flywheel and the clutch plate low irrespective of the nature of the engine.
So how do you guys manage in the stop and go traffic?? jus play with the clutch and hardly use the gas pedal? Just curious, as I invariably step on the gas with the clutch half-released - 'm I wasting fuel by doing this??

Cheers,
giga
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Old 29th August 2007, 16:09   #13
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Quote:
Originally Posted by moralfibre View Post
Btw, the did you know that using the torque in the Palio Diesel 1.9D you can shift all 5 gears at idle and the car doesn't knock but pulls at about 45-50 kmph at 800-850 rpm
Believe it or not, I could do this with my erstwhile, Indica 2000 petrol. All I had to do was to give her enough time to gather momentum in each gear. Did this many times on flat roads.
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Old 29th August 2007, 16:12   #14
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Quote:
Originally Posted by shuvc View Post
Believe it or not, I could do this with my erstwhile, Indica 2000 petrol. All I had to do was to give her enough time to gather momentum in each gear. Did this many times on flat roads.
I agree shuvc, it has everything to do with the torque Diesels put out. Makes them easier to drive in traffic.
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Old 29th August 2007, 16:43   #15
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Quote:
Originally Posted by moralfibre View Post
Was it for me bottle?

Btw, the did you know that using the torque in the Palio Diesel 1.9D you can shift all 5 gears at idle and the car doesn't knock but pulls at about 45-50 kmph at 800-850 rpm
nope that was for black pearl who posted above me

but i remember reading somewhere on the board that sometimes trying to pull from low revs at high gear etc puts more strain than higher rpms in low gear . any thoughts on that moral ? or is the torque enough to overcome that ?
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