On Feb 13, 9:32=A0am, DougS <wdsim...@[EMAIL PROTECTED]
> wrote:
> On Feb 13, 8:09 am, "trad...@[EMAIL PROTECTED]
" <trad...@[EMAIL PROTECTED]
>
> wrote:
>
>
>
>
>
> > On Feb 12, 11:56 pm, "Tiger" <tiger0...@[EMAIL PROTECTED]
> wrote:
>
> > > Only one time for my car... 95.
>
> > This is something I've always wondered about too. =A0 Many here
> > recommend cycling the glow plugs several times before trying to start
> > the car in cold weather. =A0 I've rarely done that and can't say I
> > noticed any difference. =A0 And if you think about it, I'm not sure it
> > will do any good. =A0 All the glow plugs are really designed to do is
> > get the very tip hot to serve as an ignition source. =A0The indicator
> > light is designed to go out about the time that has occured. =A0After
> > that, they stay on for probably another 2 mins or so anyway. =A0
=A0So,
> > I'm not sure what cycling them several times is going to accomplish.
> > Certainly they can't raise the temp of the cylinder head much at all.
> > And any air that is heated is quickly expelled and refilled during
> > cranking.
>
> Only one for my car as well. 84 with over 268k miles on it.
>
> Although the glow plugs aren't an ignition source. They are a pre-
> heater. They heat the pre-chamber (a smaller cavity above the
> cylinder), which is where the fuel is injected into, and they heat it
> very well. They don't have to heat the whole block or head, just this
> pre-chamber.
What makes you think they even heat the pre-chamber? My
understanding is they serve as a point ignition source. The very tip
gets to around 1000 deg and that is what ignites the fuel/air
mixture. I find it hard to believe the very tip of a glow plug tip
is going to heat anything substantial that is made of metal, whether
it be the pre-chamber or the cylinder head in 15 secs or so.
>
> As far as cycling them goes. I don't think it helps to do this. As you
> said, they stay on for a couple of minutes anyway. I have noticed that
> the light stays on longer when the ambient temperature is lower, and
> it stays on a very short period of time when the engine is warm, or
> outside air is warm. I have found on my car, that in below freezing
> temps, I need to wait a few more seconds after the light goes off, or
> just give a slight throttle when it starts. Otherwise, it starts first
> time every time.- Hide quoted text -
>
> - Show quoted text -
|
