glow plug question...

[Therunner]

sorry, i have been reading through other posts to try & find our answer & i found our little orange jk book,.
but it's not been too helpful..

on the mans 86 1.6td,
his glow plug light doesn't go out anymore,.

the relay looks very new & the big fuse infront of it is fine,. no blown fuses upfront in the cab either..

have read something about the temp sender & some 'plug',.


can someone please help me out in simple terms as to where i should look next?,

thanks

[BundeswehrBrick]

Check the relay is infact working properly...because they can overload which causes the contacts to weld themselfs permanently shut. Place a voltage tester between a glow plug or the busbar, and a good ground/earth point on the van. Turn the ignition on activating the glow plug light. Check that you have 12Volts for around 10 seconds or so after that the relay should click in and you will have no voltage. If 12v remains you may have a broken relay or a wiring fault.

Worth a try i suppose

[Therunner]

Thanks, will try that tomorrow

Melvin

[Syncro G]

The LED is not really related to glow plug operation as such. Its powered from the dash, and earthed at the relay when it wants the light on. The light is ment to show when the engine is not yet ready to start, in the preheat phase, not if the plugs are operating (there can be a few phases depending on what relay you have). While the light might normally be on for about 10sec (pre heat mode) the plugs will probubly run for over 20sec (standby mode).

Basicly your saying the LED is always on when the ignition is on?

For the LED to be on it must be being powered properly and the output from the dash must be earthing somewhere. Eather by a coroded conector, the wire shorting to ground (body), or faulty relay turning the light on when it shouldn't. Try removing the relay first, hopefully its that. If its not and a dash wiggle doesn't help its gonna be fun but important to trace short. If its the relay and but the plugs function right its no big deal, change relay when it anoys you too much.

A fault with the temp sender won't cause what you describe. Simptoms that does is LED not comming on at all or always comming on even during hot starting.

The JK book is quite good for the engine but the wireing diagram is an early one and is badly printed rendering it useless (mine copy has no wire colours on it!). If you want one for a diesel with the later fusebox send my an email adress, got it on a PDF. As far as I'm aware its not in any readilly avalable book.

[Therunner]

Basicly your saying the LED is always on when the ignition is on?

It goes out after a minute or so, or when I start the engine.
I've been assuming that the glow plugs, which are fairly new (changed them this time last year), haven't been getting hot enough, making it slow at starting?

will pm my email address re the PDF , thank you.

Melvin

[Syncro G]

Basicly your saying the LED is always on when the ignition is on?

It goes out after a minute or so, or when I start the engine.
I've been assuming that the glow plugs, which are fairly new (changed them this time last year), haven't been getting hot enough, making it slow at starting?

will pm my email address re the PDF , thank you.

Melvin

That should be a temp sender issue then. Eather the sender has broken, become unplugged, wire broken or relay dodgy.

I only know the times my relay runs for but mines not the normal type for a T3. Only heats for about 12sec with the sender unplugged (which should be enough for modern plugs to get up to temp, infact once you go over this time some self regulating plugs get a bit cooler again so waiting longer isn't nesaserally an advantage), I think the proper earlyer relays are more like 20-30sec but nothing should need a minute heat - not even my 1950's landy needs over 30sec heat and thats a really old slow design, being one of the orignal "Ricardo Comet" IDI designs.

The glow plug temp sender is identical to the dash guage sender so you could swap the wires and see what happens (if the temp guage reads funny and the relay then works proper you know its a dud sender, no change=relay/wireing), just make sure you don't mix it up with the simular looking switch for the aux coolent pump if its a turbo engine. I have a spare relay that seems to have a broken temp sensing part so it always full heats, perhaps its a common way they can go wrong, though at least you can still start them fine.

[Therunner]

The glow plug temp sender is identical to the dash guage sender so you could swap the wires and see what happens (if the temp guage reads funny and the relay then works proper you know its a dud sender, no change=relay/wireing),

this is what i've bee reading about but i don't know what they look like & where either of them are?..

[KarlT]

Interested in this thread.

Mine seem to be working correctly....as in light on / off, time on & so on but........
Smokey as HELL! for about 5 minutes, then all good. Passed emission test with ease. (not using any engine oil)

Come on Syncro G where are you?

[Therunner]

ours isn't as smokey as that!

Melvin

[KarlT]

Can get alittle embarrassing! Stuck at the lights at the bottom of our road.

[Syncro G]

Can get alittle embarrassing! Stuck at the lights at the bottom of our road.

What colour is the smoke? Unburned diesel due to low temp is white, but it doesn't usally last more than a few seconds. A think a worn turbo can make them smoke for a while when cold, not something I've yet had to do so don't know the details.

The temp senders are in the two flanges that are bolted to the head. One is on the frontward face, the other is on the top. Both flanges have big pipes going to them so follow them and look for the wires comming off. Might take some pictures if I can find my carmera charger. Theres usally 2 or 3 senderish things depending on spec, and they are interchangable so its hard to say which is which. Note which wires go where and hope they were right to start with - its only an issue on turbo engines really as there the extra switch for the coolent pump - mine had the wrong type sender for the pump and a dud relay, took a year to figure it out/sort it, hence I know it a bit too well.

[KarlT]

Can get alittle embarrassing! Stuck at the lights at the bottom of our road.

What colour is the smoke? Unburned diesel due to low temp is white, but it doesn't usally last more than a few seconds. A think a worn turbo can make them smoke for a while when cold, not something I've yet had to do so don't know the details.

.

Could it be anything else? I think/hope the turbo is good. Probably only got 15K miles on it.
I would of said 'grey' but haven't really looked recently in daylight. Definately worse in the cold weather. Seems fine after 5/10 mins or when the turbo kicks in.

[Syncro G]

Can get alittle embarrassing! Stuck at the lights at the bottom of our road.

What colour is the smoke? Unburned diesel due to low temp is white, but it doesn't usally last more than a few seconds. A think a worn turbo can make them smoke for a while when cold, not something I've yet had to do so don't know the details.

.

Could it be anything else? I think/hope the turbo is good. Probably only got 15K miles on it.
I would of said 'grey' but haven't really looked recently in daylight. Definately worse in the cold weather. Seems fine after 5/10 mins or when the turbo kicks in.

Valve seals can make engines smoke a bit (blue) from cold but again continuous after 5m seems a bit much for them. They normally give off a bit when cold started and a little puff every time they accelerate from idle, like every old ford fiesta. Corse you've got to exclude all the normal healthy (so to speak) grey/black smoke an old IDI engine should put out when under alot of load like Vmax, hard acceleration or gradients. Pump timeing being out can make smoke signals depending on how they are out too so thats worth a nice cheep check.

Smoke from poor heaterplugs is a very difinate white colour, maybe thick cloud, often acompanyed by lumpy running/misfines but soon clears when revved a bit.

Only resion I say turbo is I've herd they can make them smokey when cold if worn, don't have first hand expereance in it though (I just prey dayly that my turbo [expence timebomb] stays alright enough so I don't have to find out!).

Look at it another way, the smoke is eather diesel or oil. If its diesel something in the fuel system is a bit worn or out of ajustment, nothing a good service won't fix. If its oil somethings worn out (engine or turbo), but depending on how much oil it drinks shows saverity (asuming it doesn't drip oil too). If your pooring litres through it it needs help, but if its just smoke without much topups I wouldn't worry too much.