Z30 engine won't start cold but starts warm

Hey guys,
I've been reading a number of threads on this issue but can't find one with the exact same symptoms:

I have a 2006 Navara St-R with 200K. It had been starting fine then suddenly would not start. I was able to clutch start it then switched it off after running for about 30 seconds then didn't start again. I clutched it again and let it run for 5mins, then turned it off and it started with the key. i.e. it started when it was hot. I left it for about an hour and it started again so I'm guessing it was still warm.
I'm thinking glow plugs but I thought it should still start if they are no good (btw the glow plug light comes on and goes off like it normally does).
I've ruled out a fuel issue and I'm convinced it's electrical. If it was the CAS I would have thought it wouldn't start at all, cold or hot. It's a weird problem.
Any ideas?

I'd try changing glow plugs first. If you don't know when they were last done, it wouldn't hurt to do them. You can always get someone else to turn the key on while you check the voltage at the glow plug rail with a multimeter to make sure power is going to them

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Battery ok? What was good a few weeks ago in the warmer weather may be struggling now.

you mention you were able to clutch start the engine ? does this mean the engine will fire up when clutch started but it won,t fire up with the ignition key ? if this is true i would say your issue is either of the following; Battery / Bad Battery Terminal Earth / Starter Motor / Key Ignition Unit.

Thanks for the ideas so far... confirms what I think - it's electrical. I'll check the battery with a meter and also double check all the terminals and earths. It cranks fine.

If it cranks fine it's not likely to be the battery. These motors run the glow plugs at a lower voltage until the engine coolant reaches a certain temperature to assist in igniting the fuel mixture. If they glows aren't working properly or at all then you will have the symptoms you describe...

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If it's cranking fine it could still be a failing battery. Injector open commands occur when the ECU decides it, based on throttle position, engine temperature, engine load etc. If the ECU doesn't have enough voltage to remain operational during cranking, those injectors won't open and there's nothing like the futility of cranking an engine that's not getting any fuel.

A load test of your battery (auto electrician usually, but you can "backyard it") will reveal how much trouble you're in.

If you've got something that can suck a fair bit of juice (but NOT the starter motor!) you can give this a try. I have 2x 130W halogen driving lights - in total, about 21 amps. It's a reasonable indicator - 30 to 40 amps would be better if you can manage. Grab a voltmeter and look at the unloaded voltage - it should normally sit at around 12.6V for a battery in good condition. It's ok if it's at 12.4V, but 12.2V is a little low and may easily give a worse indication - charge it overnight, let it rest for a couple of hours then try again, measuring the voltage before putting the load on.

Ok, connect whatever your gizmo is. The volts on the battery should drop instantly. I'd expect a full battery (12.8V or more) to drop to about 12.7V with 20A of load on it, maybe 12.6V. If it fairly quickly drops below 12V for just 20A of load your battery is knackered.

It could still be battery, but the zd30 is a direct injection motor with a rotary injection pump. It is ecu controlled, but I sort of find it hard to believe that it would cut out when running, only when cold, if the battery wasn't up to scratch.

Back to the original topic, is there any smoke out the back while it is running after a roll start?

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I have checked the battery (I'm an electrician by trade and have experience with auto-electrical) and it's ok. I'll double check it in the morning to compare the voltage. I think if the battery was on it's way out it wouldn't start at all. It's definitely something to do with cold starting so I'm leaning towards the glow plugs. There is a cold snap at the moment and I'm thinking that the glow plugs are not quite getting the temperature to the right level to start. I leave it for hours during the day when the outside temp is higher and it starts every time.
I could be wrong about the battery but I'll know in the morning.

@ bods - yes there is a bit of smoke when I clutch it - does that mean something?

Again - thanks for all the advice. I hope I'll be able to give something back to the forum by solving this problem and letting everyone know.

If it is white smoke it is probably unburnt fuel that isn't burning because the combustion temperature is too low...

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bods said:

If it is white smoke it is probably unburnt fuel that isn't burning because the comnustion temperature is too low...

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Click to expand...

Aha... makes a lot of sense. I've noticed a little bit of smoke starting to happen during start up even before this, so the glow plugs could have been on the way out before this problem happened? I'll be tackling that job this weekend. Will let you know how it goes...

Yeah there may have only been 1 or 2 dodgy ones, but if 3 or even all 4 of them have now given up she won't be liking the cold mornings...

That should have said combustion obviously hahaha. Fat fingers.....

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Cold Start problems

Good Morning Richie,

About eight months ago I had a similar problem and with my D21, SD25,
1987 Model, and I remembered one of my jobs on our Ice cold Farm in a
cold Winters day was to light fires in "cut off drums" and place these under the Oil Sumps for about twenty minutes on our Tractors then load the "Shotgun Cartridge", set the Cylinder position and strike the firing pin and start all three for their long days work!

I am not saying you should light any Firedrums under your Nissan Ute, but I would give some serious thought to a "Ladies Hairdryer" or a Paint Stripper Heater of
any brand and place this in the Air intake after removing the "Air Filter" and heat her up until it is bloody hot and try your luck, If there are any little bits and pieces I may have missed adding, I'm sure others will add to this solution for your assistance!

This solution was manly required on very cold Mornings in very cold Motors, and
your Warmers are not getting full power or are covered in Soot and require a cleanup!

I hope this is some help to you,

Best of luck with your problem!
highway man
Hillman 6168.
Western Australia.