Intermittent coil light (and cold start )

Hi.

Please bear with me on this, I have done a fair bit of searching on here and other forums, but im finding myself getting confused after reasonable diagnostics (at my level)

Imported Jap 300tdi with blanked off EGR.

Starts fine all year, as soon as it gets to zero, its a pain in the arse.
It will crank over, but wont fire, then the cranking kills the battery so I swap it with a charged one and it fires up etc etc ad invinitum


Relay clicks ok, Fuses fine, Battery starts off at around 15.4v and is 1000CCA
I put a multimeter on the glow plug tip and the neg on the engine case and it reads 0, put neg on battery and its 0.1v (Would Amps be more use ?)

And then yesterday I noticed it started fine after a previously unseen coil light appeared, and it started in a kind of cold I wouldnt normally expect it to start in. Not seen that light again (hence me looking up relay probs and checking for clicks and fuses etc)

I ordered new plugs earlier this week, will that fix it? there appears to be a bigger issue with power reaching the plugs (unless im being a div which is more than likley)

Any ideas on what I need to check next ?

I know its Range Rover, but does this apply to the 300tdi ? Would make sense
http://www.landyzone.co.uk/lz/f10/possible-glow-plug-problem-264047-3.html

Have you tried running a live feed from the battery to the fuel cut off solenoid and then trying to start the engine?

But remember though that the engine wont stop unless you pull the wire off.

Fozzie.

I,m guessing that the "little coil" light is your glow plug heating light.
You should wait for this light to go out before trying to start.
Even in extremely cold weather, let the light go out, switch off, switch on again and wait for the light to go out.
Even when the light goes out count to 5 as the glowplug keeps heating after the light goes out
Hope this helps.


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Cheers guys, really appreciate your inputs. No ive not tried the fuel solenoid trick but tbh, I may try that i I can get some help from a mate.

Yeah I know its the coil light, but I dont understand why it only ever comes on once in a blue moon. Thats whats befuddling me

Can you hear the relay "click" as it goes out? I once had a motor where the light came on very briefly and off again time span of around 2 or 3 secs and even though the light went out the relay was heating the glow plugs for around 30 seconds, I just waited for the "click" then cranked the engine.

I would run a second earth strap direct from the battery negative to the block, use one of the unused threads for the aircon pump if you don't have A/C or one of the timing cover bolts for grounding if you do, then chase the connections to the relay making sure they are all solid.

It might be worth while replacing the stop solenoid and glow plugs and glow plug relay with new(genuine is best!) parts and going from there, it is not expensive and will ensure that all key components are in tip top shape and will help with finding out if you have any other issues.

Bench test new plugs before fitting, I bought loads over the years and found that probably 1 in 10 was faulty!!!

The wife could hear the relay click but i couldnt from the cab.
Il check the relay points and if nothing happens il try your tip
Got new plugs on the way, I guess it cant hurt to try a new relay as well

This sounds like a clear cut glow plug issue - so waste no other effort on anything else until you look into these. As a very basic test, wait for a cold morning, get a piece of wire and run it from the positive battery terminal to the tip of one of the glow plugs, give it a good 10-15second glow, it should spark a bit as you push it onto the tip - this indicates they are drawing current, as you disconnect the plugs have an apprentice turn they key straight to the start position. If she bursts into life you have your diagnoses confirmed - now fix.

If the coil light came on randomly, then it could be a shot GP relay, it's next to the engine bay fuse box, big one with 5 wires, 2 heavy 3 light if I remember correctly.

Could be iffy wiring too or an ignition switch to GP relay issue.

When the GP light is on, you should see battery voltage at the GP tips.

I have a manual GP switch on my 90 - only use it to start when REALLY cold, not used it for over a year.

Sounds to me like your engine is one of the 300tdi's that don't like the cold. I doubt there is anything wrong with your fuel solenoid as you say it starts on another battery eventually.

I had a 300tdi Disco and have a 300tdi 90. I could always count on the 90 to start without glows at all - the disco needed a tip top GP system and on cold mornings I gave it two GP sessions before I started her and then she would ALWAYS start. No GP's and I could flatten the battery trying.

I eventually solved this by fitting a bigger, faster starter motor.

dieseldog69 said:

I would run a second earth strap direct from the battery negative to the block, use one of the unused threads for the aircon pump if you don't have A/C or one of the timing cover bolts for grounding if you do, then chase the connections to the relay making sure they are all solid.

Click to expand...

If it was an engine ground issue the engine wouldn't turn over.

discomania said:

If it was an engine ground issue the engine wouldn't turn over.

Click to expand...

That is a recommendation I first make to anyone with any type of electrical issue with their Land Rover, the earth direct to chassis and then jumping over the rail to the gearbox worked for the first 10yrs but it is such a common issue in older Land Rovers it is one of the first things to recommend, if done now then at least the OP can be sure that future probs won't be earth related, £4.50 now for a copper strap or £35 for a H/brake cable when the current welds it up

the ****part glow rods arrived today, so will test em and fit them in see if that sorts it. Will report back when done

Sounds like ur Relay is shot too

If the light is intermittent more likely the relay side of things.

Does the light come on at full brightness or just dimly?

its either on or off, in fact ive only seen it come on once in the last week, scince i noticed it. Not dimmed or anything

Change the Relay Next thing will be that it will start draining your battery!

UPDATE: New relay fitted, all sorted.

The pins were pretty corroded, probably coul have just sanded them and plugged it back in, but hey ho im pleased.

Cheers for the input peeps