Kill switch

[BeeUU]

I have completed my first experiment in the quest for ultra mileage!!!

I tried "coasting in gear" with the motor turned off. Wide open throttle does not improve coasting length significantly. I guess engine and driveline drag are really a big component of overall drag.

It makes for a smooth engine start. Turning the key to "ON" while coasting with the engine engaged produces no noticeable noise or power change.

I also coasted with the engine off and disengaged. Then re-engaged the engine and turned the key to "ON". Smooth as silk. Boy this is fun. But it takes a bit of concentration right now.

I have become more motivated to install the injector kill switch, turning the key to "OFF" while moving is just so against the grain, it is hard to do the first few times. It feels so "wrong" and the silence is weird too. The results are so "right" though!!!!

[cfg83]

BeeUU -

Originally Posted by BeeUU

I have completed my first experiment in the quest for ultra mileage!!!

I tried "coasting in gear" with the motor turned off. Wide open throttle does not improve coasting length significantly. I guess engine and driveline drag are really a big component of overall drag.

It makes for a smooth engine start. Turning the key to "ON" while coasting with the engine engaged produces no noticeable noise or power change.

I also coasted with the engine off and disengaged. Then re-engaged the engine and turned the key to "ON". Smooth as silk. Boy this is fun. But it takes a bit of concentration right now.

I have become more motivated to install the injector kill switch, turning the key to "OFF" while moving is just so against the grain, it is hard to do the first few times. It feels so "wrong" and the silence is weird too. The results are so "right" though!!!!

When I am coasting engine-off in neutral, I usually turn the key to "ON" and do the bump start with my stick shift. Never thought of re-engaging the gear first and then turning the key "ON".

And yes, the injector kill switch must be the way to go. I should add that to my to-do list. *sigh*

CarloSW2

[skewbe]

ya know, when I kill the engine, I shift to neutral and the daytime running lamps go out.

Strangely reminiscent of "kill the headlights and put it in neutral"...

[GasSavers_BluEyes]

Originally Posted by skewbe

Ya know, mine still takes a while to die. It seems to stumble and shake a bit right before zero rpm. I'm running a bottle of injector cleaner through it now, will see if that helps.

That's probably because you have throttle body injection on the Metro. Look down on the throttle blade with the engine running - you'll see a skim of liquid fuel on the throttle blade where the injector sprays it. Even after you shut the injector off, the engine won't die untill that fuel has gone away, thus the shaking and stumbling as the fuel supply runs out.

Cars with multi-point fuel injection shouldn't have this because the injection goes directly into the ports so there would be no 'reserve' supply of fuel for the engine to run on.

I think whether you leave the trans in gear or not depends on the hill. I have some around here where I want the engine braking! I have to occasionally use the brakes even with the engine in gear so if I put it into neutral I'd really be burning up the brakes.
Personally, if you put it in neutral I'd much rather do a rolling restart with the starter than a bump start. Just use the starter and avoid the clutch wear, plus you can do it at speed if you are not comfortable doing a bump start at highway speed.

[cfg83]

BluEyes -

Originally Posted by BluEyes

That's probably because you have throttle body injection on the Metro. Look down on the throttle blade with the engine running - you'll see a skim of liquid fuel on the throttle blade where the injector sprays it. Even after you shut the injector off, the engine won't die untill that fuel has gone away, thus the shaking and stumbling as the fuel supply runs out.

Cars with multi-point fuel injection shouldn't have this because the injection goes directly into the ports so there would be no 'reserve' supply of fuel for the engine to run on.

I think whether you leave the trans in gear or not depends on the hill. I have some around here where I want the engine braking! I have to occasionally use the brakes even with the engine in gear so if I put it into neutral I'd really be burning up the brakes.
Personally, if you put it in neutral I'd much rather do a rolling restart with the starter than a bump start. Just use the starter and avoid the clutch wear, plus you can do it at speed if you are not comfortable doing a bump start at highway speed.

I do like "bump start in 5th at 30 MPH" because I can usually do it really smooth. For higher speeds I think that I will use the starter.

Question : Hmmmmm, won't the starter cause the lights to go off/on? That may be a flag to the powers that be, especially at night . Gotta think about it.

CarloSW2

[GasSavers_BluEyes]

Originally Posted by cfg83

Question : Hmmmmm, won't the starter cause the lights to go off/on? That may be a flag to the powers that be, especially at night . Gotta think about it.

CarloSW2

Dunno if all the dash lights will come on because you haven't cycled the ignition switch. Lots of cars have things like the 'brake' warning light wired to come on during cranking as a test to see that the bulb is still good though. If the ignition has never gone off I think the check engine light should stay off though?

I tried turning the ignition off today down some hills (my steering wheel only locks after 180* so no worries) and when I turn the ignition back on of course all the lights go their thing. I left it in gear with the clutch engaged though to retain power steering, brakes, and engine braking so no need for a bump or starter.
I didn't think it was bad to coast with the engine off. I've only heard about coasting in neutral being illegal. Possibly due to a risk of overheating the brakes from a lack of engine braking? Doubt a cop in traffic is watching your dash. Might hear the starter though...

I did some off-site research and did find something to consider. Engine-off coasting in neutral does not seem like a good idea for manual trannies. In that situation, none of the gears are turning, so no oil gets distributed, possibly damaging the bearings. I hadn't thought of this, but having been inside a few trannies it is true. Only the output shaft will spin and the gears will remain stationary. Leaving the trans in gear with the clutch in will leave the gears engaged and turning without turning the engine over, so no risk of frying bearings. (the throwout bearing would not be rotating either, so no risk to it either from leaving the clutch pedal in for so long)
I have no idea about auto trannies - still learning the mechanics of them.