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Glowplug testing info needed please
Posted: Thu Nov 11, 2010 7:52 pm
by Jimblob
Hi chaps,
My car struggles to start in the cold mornings, but is always fine when warmed up.
I thought I'd check the glowplugs with the multimeter. The supply to each plug when the ignition is on is about 2.2V. This sounds too low, I thought it would be 12V. Any ideas?
The resistance on each of them is about 0.08 ohms.
There's no variation from plug to plug..
Once it starts, it runs fine, no spluttering etc. It's the 110 HDi.
Thanks
Jim
Re: Glowplug testing info needed please
Posted: Thu Nov 11, 2010 8:07 pm
by Gary406
install new plugs ??
Re: Glowplug testing info needed please
Posted: Thu Nov 11, 2010 8:09 pm
by steve_earwig
Not if the feed's only 2.2 volts

Is that with the glowplugs disconnected? Was it peak?
Re: Glowplug testing info needed please
Posted: Thu Nov 11, 2010 8:11 pm
by Jimblob
2.2V is with the glowplugs disconnected, that's measuring on the plug that goes onto the glowplug.
Ignition on, engine not running, that's the voltage.
It should be 12V, right?
Re: Glowplug testing info needed please
Posted: Thu Nov 11, 2010 8:12 pm
by steve_earwig
Briefly, although I'm not sure if the post-heating happens if the engine isn't started
Re: Glowplug testing info needed please
Posted: Thu Nov 11, 2010 10:12 pm
by poddack
mmmmm, should be 12v, can you angle the meter in such a way you can see from the driver seat, it should go to 12v along with the yellow glowplug light and shortly after the light has gone out, the colder it is the longer it should stay at 12v. Probable glow plug relay!
Re: Glowplug testing info needed please
Posted: Thu Nov 11, 2010 10:21 pm
by Jimblob
Thanks I'll do that check again with a cold start to be sure viewing the meter.
Where's the glowplug relay located?
Re: Glowplug testing info needed please
Posted: Thu Nov 11, 2010 10:39 pm
by jasper5
The glow plug relay is built into the ECU.
You would be best checking the glow plugs with a test lamp, remove all glow plug connections then connect the test lamp to the battery positive, the other test lamp wire should be connected to each glow plug in turn, if the lamp lights when you touch the glow plug terminal then it's working.
If you still aren't happy, remove the plugs and connect a jump lead to the battery earth and live,then live and earth on the plug, if it glows, it works.
I would have your battery tested.
Re: Glowplug testing info needed please
Posted: Fri Nov 12, 2010 6:53 am
by steve_earwig
Err, I'm probably going to regret saying this (seeing as how it's Jasper an' all) but
jasper5 wrote:The glow plug relay is built into the ECU.
The glowplug relay is on a bracket below the throttle potentiometer (you thinking of the lift pump relay?)
It is on mine...
Btw mine's the later EOBD type, yours will be the earlier one (up to 2003)
Re: Glowplug testing info needed please
Posted: Fri Nov 12, 2010 8:18 am
by jasper5
steve_earwig wrote:Err, I'm probably going to regret saying this (seeing as how it's Jasper an' all) but
jasper5 wrote:The glow plug relay is built into the ECU.
The glowplug relay is on a bracket below the throttle potentiometer (you thinking of the lift pump relay?)
It is on mine...
Btw mine's the later EOBD type, yours will be the earlier one (up to 2003)
Ah right, thanks Steve, I thought it was in the ECU....sorry, my mistake

Re: Glowplug testing info needed please
Posted: Fri Nov 12, 2010 12:36 pm
by Jimblob
No offence Jasper but I was going to reply, saying I hope he's wrong as an ECU replacment would be undoubtedly expensive!
I hoped someone would step in with a second opinion
OK so I might have a crack at checking the relay.. any tips or do I just put 12V on it and listen for a click?
Re: Glowplug testing info needed please
Posted: Fri Nov 12, 2010 12:41 pm
by steve_earwig
Ok, I reckon you need to check the output from the relay for a full 12 volts. You'll either need an assistant to turn the "ignition" on or some way of watching it 'cos it won't be on for long.
Re: Glowplug testing info needed please
Posted: Fri Nov 26, 2010 11:07 am
by Jimblob
Latest with my cold start problem is that I've put some injector cleaner in (twice the recommended dose) and I now find that it is starting a little faster.
One thing I have noticed (or I think I have noticed) is that it starts faster if you keep your foot down on the accelerator when turning the ignition?
Any logic in this?
J
Re: Glowplug testing info needed please
Posted: Sat Nov 27, 2010 2:20 am
by totaleclipse
ifit cold starts without spluttering, leave it alone.
Re: Glowplug testing info needed please
Posted: Sat Nov 27, 2010 6:03 am
by steve_earwig
Jimblob wrote:Any logic in this?
It would kind of suggest it's having trouble getting up to idle speed on its own.