Page 1 of 1

Glow Plug Light

Posted: Wed Nov 15, 2006 3:02 pm
by Andres
I've had a search, but coudln't find the exact answer. And read the manual too, which wasn't 100% clear either... so...

On a 12HT 60-series, should the glow plug light come on? Mine never comes on, but also it stars instantly. Basically no "cranking" at all to get it started. It runs a little rough to begin with, but doesn't stall or anything. Just vibrates a bit.

So should the glow plug light be coming on? (On the Cherokee, the light would come on everytime from memory). This car is new to me, so want to get everything up to scratch before i start leaving the 'burbs.

Re: Glow Plug Light

Posted: Wed Nov 15, 2006 5:36 pm
by Shadow
Andres wrote:I've had a search, but coudln't find the exact answer. And read the manual too, which wasn't 100% clear either... so...

On a 12HT 60-series, should the glow plug light come on? Mine never comes on, but also it stars instantly. Basically no "cranking" at all to get it started. It runs a little rough to begin with, but doesn't stall or anything. Just vibrates a bit.

So should the glow plug light be coming on? (On the Cherokee, the light would come on everytime from memory). This car is new to me, so want to get everything up to scratch before i start leaving the 'burbs.
The 12HT doesnt use glow plugs it uses a glow screen which heats the air as it goes through the inlet manifold, so in theory it will work when your cranking, as opposed to a glow plug which heats the air in the bore and the bore itself, hence glow plug you wait for them to heat up, then crank, glow screen i think you have to be cranking for it to do its job.

But having said that, it is a very very common thing(fault) for the glow light in a 2H HJ60 to only stay on for about 2 seconds, whilst the glow plugs stay energised for about 10 seconds. I always wait until i hear the GLOW solenoid click off (its in the drivers side kick panel so very hearable), or you can watch the voltmeter and it will change voltage when the glowplugs(screen) switches off. So perhaps the same has happened to your glow light.

Maybe listen for the click or watch the voltmeter and see if you can pick when the glow screen switches off.

If It switches off when your engine is running in you may not be able to hear solenoid switch, and probably not see the voltage jump either since the altenator has kicked in.

Posted: Wed Nov 15, 2006 5:45 pm
by Shadow
The circuit schematic in the toyota manual shows that its exactly the same as the preheat circuit as my HJ60, except for the glow plug/intake heater specific stuff.


I would listen for the click or watch the voltmeter and see if you can pick when the preheat timer is cutting out.

In troubleshooting it says to check for continuity between the terminals of the intake heater. NO -> Replace intake heater

Then to measure the voltage at the intake heater, with the ingition at ON. It should have battery voltage for 20 seconds. NO -> check fusible link for intake heater.

It then describes the method to debug the preheat timer circuit.


Could be just a faulty globe?

Posted: Wed Nov 15, 2006 7:04 pm
by Bowhunter
I have an '86 diesel, 2.4 L. (not sure which model engine - how do I find out?).

I have only had the vehicle 2 weeks but notice occasionally that the "glow plug" light on the dash flickers on and off every now and then - usually when up around 2800+ RPM.

It does not come on at all when I first turn the key to the "on" position when starting (I leave it at "on" while I do up my seat belt to make sure it's had time to heat up even if dash light is not illuminated).

The engine fires instantly every time.

Would anybody be able to tell me why it flickers some times?

cheers.

Luke

Posted: Wed Nov 15, 2006 8:07 pm
by Shadow
Bowhunter wrote:I have an '86 diesel, 2.4 L. (not sure which model engine - how do I find out?).

I have only had the vehicle 2 weeks but notice occasionally that the "glow plug" light on the dash flickers on and off every now and then - usually when up around 2800+ RPM.

It does not come on at all when I first turn the key to the "on" position when starting (I leave it at "on" while I do up my seat belt to make sure it's had time to heat up even if dash light is not illuminated).

The engine fires instantly every time.

Would anybody be able to tell me why it flickers some times?

cheers.

Luke
could be a faulty preheat timing unit, or a bad glow plug relay which is firing up your glow plugs intermitently.

Posted: Wed Nov 15, 2006 8:11 pm
by Bowhunter
Thanks Shadow...

So what might be any damage associated with this?

cheers

Posted: Wed Nov 15, 2006 11:16 pm
by Shadow
Bowhunter wrote:Thanks Shadow...

So what might be any damage associated with this?

cheers
No idea how you would go about diagnosing the problem. I would try to isolate each component of the preheat system and check them individually. The relay and preheat timer are going to be difficult to test though.

Posted: Thu Nov 16, 2006 7:48 pm
by frp88
my middies 13bt does the same starts straightaway and my glow light which is under the filter light never comes on.I cant see any power going to where the injector are.

Posted: Thu Nov 16, 2006 7:51 pm
by Shadow
frp88 wrote:my middies 13bt does the same starts straightaway and my glow light which is under the filter light never comes on.I cant see any power going to where the injector are.
13bt probably uses a inlet heater aswell then. check your manifold for power and grund connections. I think it sits on top of the manifold inlet, so if you remove your crosover pipe you should be able to see the screen.

Posted: Fri Nov 17, 2006 3:33 pm
by vSAHARAx
Andres I have a 12HT in my HJ61 Sahara, and mine has never worked either, im in brizzy and in the coldest of coldest mornings we get here still nothing, i asumed something was wrong with it. Until in June i drove to the snow (Thredbo), When i needed to start my car (in the morning) when i turned the ignition on, guess what worked, The Glow Plug Light :P , it stayed on for a few seconds, then i heard the glow solenoid click off and the volt meter return to normal. I did that a couple times and she would start first go! the first time i tried to start it before the light turned off it just kept cranking.

So i wouldnt get to worried about it, mine has only worked in freezing conditions, as long as she starts first go its all good :armsup:

Troy.

Posted: Fri Nov 17, 2006 5:37 pm
by frp88
Shadow wrote:
frp88 wrote:my middies 13bt does the same starts straightaway and my glow light which is under the filter light never comes on.I cant see any power going to where the injector are.
13bt probably uses a inlet heater aswell then. check your manifold for power and grund connections. I think it sits on top of the manifold inlet, so if you remove your crosover pipe you should be able to see the screen.
yep power terminals at the inlet