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Colorado glow plug change needed??


Feb 12, 2021
Country Flag
Hello all.
No reals problems but the old Collie takes a few turns to start recently. Guess maybe because its colder. Batteries are fine, just wondering if the Glow Plugs need a change.
I've read around and some say change at 100,000k, some say don't bother unless they fail definitely.
Is it an easy job? they seen cheap enough of RoughTrax.
3.0 LWB has done 150k miles. 1997 KZJ95R engine.
Answers on a post card!!
Check whether you have voltage going to the glow plug buzz bar when your ignition is turn on (not starting) when engine is cold. You should see 10-11v for 10 seconds or so. At least to make sure that voltage is being supplied to the plugs. Then further trouble shoot if this is ok.
9.5v at the bus bar, not sure if it was 10 seconds. It seemed less that that. I checked the resistance of the first Plug, reading was .8 ohms so taking the leads into accout it was about .7 ohms. Second plug was 1.1 ohms so taking the leads into account 1 ohm. I can't get to the back two plugs without taking the manifold off. Glow plug relay maybe?
Is it worth trying injector cleaner as I haven't put any through for a few years?? 12.6v at the batteries.
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Seems like the plugs are doing their job. The slow start, is it regardless of warm or cold engine?
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slower cold, quicker warm
Is your fuel filter plunger soft after you stop the engine? The one you pump to draw fuel from tank.

Happened to mine few weeks ago (slow start cold or warm), turn out that i have a corroded fuel pipe on top of the tank.
One Ohm or less per plug is good.

Hi Bob, hope you are well.

I always thought that anything above 1 ohm is not good for glow plug, but the glow plugs I put in mine from NGK all have 1.4ohm new.

See description within the table linked above.
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Well, checked the pump and all looks good. In all fairness it started ok this morning, so now I'm scratching my head. I've put 1/2 bottle of diesel cleaner in the tank with £50's worth of fuel. I'm just hoping its just one of those odd hicupps. I'll check the resistance of the back two cylinders over the weekend to make sure.I'll give it a 50 mile run to watch the rugby tonight in Gloucester so hopefully it'll clear the tubes out a bit.
One question, is it reccomended to change the Glow's after a certain period?
Thanks both for your comments its really appreciated.


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Evening all.
Well, my Coloroado is still struggling a bit to start even after I changed the fuel filter. Attached an before and after of the inside of the old and new filters. I'm thinking it might be a clogged EGR valve.
Has anyone used the Wynn's EGR Cleaner and whats the thoughts on it, did it work or did it bugger something up??
I'm running out of options now before I have to take it in to get looked at. As mentioned the Glow plug voltage is good and all have around 1 ohm resistance.
It fires straight away then just cranks a few times then starts...:anguished:


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