Not starting, glow plug issue?

[therealchrisgray]

Hi all, greetings from the Outer Hebrides - where my 1.9 diesel van has decided not to start when cold! (ie every day)

I drove it last week no problem, but when I came to go home it just cranked over with no sign of any combustion. It usually starts first time, so this was worrying.

After enough attempts that I was starting to fret about draining the battery, it finally caught and blew a big cloud of white smoke (vapour) out the exhaust before settling down to running normally. Came back to it a few days later, it wouldn't start and I didn't have time to fiddle with it so I left it til today.

It seems I have fuel, compression, and power in the battery, so I did a few experiments:
- remove a glow plug and connect directly to battery for a few seconds, it got very hot
- multimeter on the (disconnected) power cable to the glow plugs indicates no current flowing on key turn
- a wire from the battery to the glow plugs for a few seconds resulted in it starting immediately I turned the key
- once the engine was hot I turned it off and it restarted easily

So I'm 95% sure I'm not getting power to the glow plugs when I turn the key, although the orange light does come on for ten seconds or longer. And I know nothing about vehicle electrics.

Can anyone advise on how I would go about tracing the fault, as a beginner?

[hotpod]

There should be a glow plug relay somewhere. Mine is in the engine bay in a black plastic box on the left hand side wall.
I would start there.
At the start of your post I was suspecting air in the fuel line but since you tried the glow plug tests then I would first check you are getting ignition power to the relay first. And firt find your relay. Trace the cable back from the glow plugs and you should find it.

[therealchrisgray]

At the start of your post I was suspecting air in the fuel line

Yeah, that caught me last year!

[mioba]

GP light should go off very quick this time of year.

Have you checked the GP strip fuse in the black
box off engine bay. Always have a few spare.

[therealchrisgray]

There should be a glow plug relay somewhere. Mine is in the engine bay in a black plastic box on the left hand side wall.

Found it!

Can anyone advise before I buy a new relay? Have I forgotten anything?

This is all a bit hit and miss because I'm on my own and don't have anybody to turn the key for me. But since the orange light stays on for at least 10 seconds, I have time to turn the key and then run to the back of the van to check stuff, but here goes:

I checked that the relay is getting battery power, at one of the two terminals beneath it. But no power out to the glow plugs, even with the ignition key on.

I double checked this by connecting a wire directly from the output terminal to the glow plug bar and trying to start the van. No glow!

I also used the audio recorder on my phone to check whether the relay solenoid is firing, I left it next to the relay while I went and turned the key a few times, and I could hear it clicking in the recording.

Then I removed the relay and poked around with a multimeter, and got a 12-volt reading in the slots with the key turned. So I think this confirms I'm getting power to the relay from the key?

The AI tells me the internal contacts in the relay are probably burnt out. But I wanted to check with some actual humans that know what they're talking about!

Is there anything else I need to check? Other potential issues I haven't considered?

Thanks all

[hotpod]

A really handy diagnostic aid I have found useful many times is a coil of wire with crocodile clips which is long enough to reach from the engine bay to the dashboard.
In your case, you can then connect it to the output side of the relay you are checking in the engine bay and connect the other end to a miltimeter at the dash end. You can work your way through the circuit and see at what point the current stops.
Before I had a multimeter I had a 12v bulb soldered at the end with a shorter cable to earth it. 
 

[therealchrisgray]

Sigh, I got a new relay and it still won't start.

My first thought was that it's the socket the relay plugs into, then the AI suggested there's a temp sensor that is either not working or not getting a message back to the relay.

Too hot to do anything more with it today, but if anyone wants to suggest other points of potential failure I would be grateful.

Just to confirm, I do have power to the relay from the battery, and also from the ignition key, and can hear the relay solenoid clicking.

[therealchrisgray]

GP light should go off very quick this time of year.

Hmmm, I'm getting a good ten seconds before it goes off. I started looking for the sensor just now, but gave up. Long day doing other jobs as well!

[The Hairy Camper]

1.9 1Y and AEF engines often require a resistor connected to the glow plug temperature sensor when installed on our old vans. Do you know if you have one installed?

These engines like to have an extra long shot from the glow plugs to get started, even when the engine is hot.

I'll try and post a picture of mine.

[The Hairy Camper]

This is the temperature sensor for the glow plugs.

A 600ohm resistor seems to do the trick.

[therealchrisgray]

This is the temperature sensor for the glow plugs.

Thanks, can you zoom out a bit? I don't recognise that part of the engine

[therealchrisgray]

A 600ohm resistor seems to do the trick.

Where do you put that? Newbie with close to zero electrical knowledge, remember!

[clift_d]

If you haven’t done it, It might also be worth checking that the wiring from the relay to the glow plugs doesn’t have any hidden breaks.

[The Hairy Camper]

This is the temperature sensor for the glow plugs.

Thanks, can you zoom out a bit? I don't recognise that part of the engine

Top left of the engine bay