Glow plugs, lights, and clicks!

[tonydca]

So I'm working my way through my start-up sequence, and the consensus from this forum seems to be the following:

On a cold (more on "cold" in a second) startup, one turns the key to "On" - big relay click left side of dash. Presumably glow plug relay engaging. After 6 seconds, click again. Presumably relay off. Turn key, vrooommm, off you go.

But, after about 30 seconds of driving, I hear another "click" comparable in size and location to the original glow plug relay. Before I dive in with my meter, I'm wondering if anybody knows if the glow plugs are left on at a lower setting to help the engine from stuttering while it starts to warm up?

More importantly, there is cold, and there is cold(er). I am finding that when the vehicle has been sitting all night in my underground garage (around 10 degC), she starts up as indicated above, first crank, no smoke, no fuss, no muss - easy-peasy.

However, when she's been outside at 3degC, there are two differences.

First (minor) is that when the key is first turned "On", there is a small glow-plug indicator light in the lower left corner of the dash that comes on with the relay engaging, but goes out (silently) after about 1 second. If I turn the key off then back on (without trying to start), same thing - little indicator for a second. So I'm wondering what the light is actually indicating, since it is not tied directly to the relay.

Second (less minor) is that this small temperature/humidity change is making a big difference in starting. crank crank crank 8-10 times or more and lotsa white (unburned diesel - to be expected) when she catches on the second or third try. I've tried cycling the key on and off (waiting for the relay to click in and out each time) before trying to start to get a bit more oomph from the plugs - no joy.

Mardy is logically suggesting different plugs, but I'm wondering if perhaps my starting technique is off - this here diesel thingy is new to me and my wife. I am always starting with my foot off the gas pedal, and this was how my old gas toyota fired up. Does giving it some pedal on startup help, or not? My thoughts are that it would be introducing still more fuel into the cold cylinder to be unburned, so I'm thinking "not".

Anything I'm missing?

[Green1]

On a cold (more on "cold" in a second) startup, one turns the key to "On" - big relay click left side of dash. Presumably glow plug relay engaging. After 6 seconds, click again. Presumably relay off. Turn key, vrooommm, off you go.

But, after about 30 seconds of driving, I hear another "click" comparable in size and location to the original glow plug relay. Before I dive in with my meter, I'm wondering if anybody knows if the glow plugs are left on at a lower setting to help the engine from stuttering while it starts to warm up?

The plugs do stay on at a lower setting after startup until the engine reaches a certain temperature, they can also cycle on and off a few times shortly after starting.

More importantly, there is cold, and there is cold(er). I am finding that when the vehicle has been sitting all night in my underground garage (around 10 degC), she starts up as indicated above, first crank, no smoke, no fuss, no muss - easy-peasy.

However, when she's been outside at 3degC, there are two differences.

First (minor) is that when the key is first turned "On", there is a small glow-plug indicator light in the lower left corner of the dash that comes on with the relay engaging, but goes out (silently) after about 1 second. If I turn the key off then back on (without trying to start), same thing - little indicator for a second. So I'm wondering what the light is actually indicating, since it is not tied directly to the relay.

the glow plug light is on until the "minimum" time you can use to start personally I wait a few seconds after it goes out before starting.

Mardy is logically suggesting different plugs, but I'm wondering if perhaps my starting technique is off - this here diesel thingy is new to me and my wife. I am always starting with my foot off the gas pedal, and this was how my old gas toyota fired up. Does giving it some pedal on startup help, or not? My thoughts are that it would be introducing still more fuel into the cold cylinder to be unburned, so I'm thinking "not".

You shouldn't need to apply any pedal, and there's a good chance you need new plugs, especially if you don't know when they were last done. sounds like you're starting procedure is correct though

[tonydca]

I swapped the plugs today, so I'll see how that works. My wife is off to work tonight and it's 4degC and rainy, so should be just like this morning for a left-out-in-the-cold comparison test! Depending on how easily she cranks it over, I'll know by 8:00 am what kind of day I'll have tomorrow - a happy wife makes a happy life!

There are a bunch of posts on the UK site talking about the difference between "normal glow" and "super glow"; the latter is what I think these L400s have, whereby they dump a lot of current into the plugs for the first 5 sec or so, then keep them on at a low level, as you say. for a while longer.

WRT the coil light on the dash, sometimes it is on for several seconds, sometimes just for a flash. I'm wondering if it is sensing the current draw for the plugs (current would decrease as they get hotter and their resistance goes up). The consensus over there seems to be that once the coil light goes out, you should be able to fire it up, even before the second "click" (primary relay switching off after 6 seconds).

Tony.

[delicabits]

have you checked the amount of power getting to the glow plugs from the bus bar. the wire that joins to the bus bar tends too get brittle. try putting a second wire between 3rd & 4th plugs to aid with heating.

[Todd64]

When I read the thread title first I saw "Glow plugs, lights, and chicks!"

[tonydca]

When I read the thread title first I saw "Glow plugs, lights, and chicks!"

My wife thought I'd written "dicks". Can you folks not get your minds out of the gutters for 2 seconds

For the record, swapped plugs, polished the bus bar (it is a factory version with the feed wire on a lug between plugs 1+2 instead of connected up direct to #1) and she started up first crank out in the cold and damp.

Gut gemachter Herr Diesel und Herr Mitsubishi!

[Green1]

WRT the coil light on the dash, sometimes it is on for several seconds, sometimes just for a flash. I'm wondering if it is sensing the current draw for the plugs (current would decrease as they get hotter and their resistance goes up). The consensus over there seems to be that once the coil light goes out, you should be able to fire it up, even before the second "click" (primary relay switching off after 6 seconds).

my understanding is that the coil light is sensitive to a temperature sensor, once the glow plugs have warmed things up "enough" it goes out and you should be able to start, now waiting another second or two doesn't hurt, but waiting any delay after the second click and you start to undo the work done by the plugs.