Cold start struggles

[benpayne92]

Hey guys im having trouble with cold starts.
ive got a 3.0ltr and have recently put new glow plugs and new injectors in, thinking this would resolve the issue but it hasn't
When i first start my car after its been sitting for a few hours and has cooled down, it takes 5-6 seconds of ticking over to start then blows a big puff of white smoke for approx 2 seconds then once that clears up it runs fine.
where should i start looking?

 

[Old.Tony]

Sounds like there's a leak in the fuel system that is allowing fuel to drain back to the tank. There's a very easy test for this: instead of starting the car, pop the bonnet and squeeze the primer bulb. It should take no more than 5-6 squeezes before the bulb becomes firm and harder to squeeze.


If you have to squeeze it more than 5-6 times before it becomes firm, the next trick is to keep squeezing it and look for any diesel dripping out. On my car, when the mechanic forgets to click the water sensor in place at the bottom of my fuel filter, I have the same problem, went through the same process, and found fuel leaking from the bottom of my filter, went "ahhh" and tightened the water sensor - easy, easy fix.


Let us know how you go!

 

[benpayne92]

Hey mate thanks for the reply, i went and checked after it had been sitting nearly 24 hours, it only took 3 squeezes to become hard

 

[Old.Tony]

Then there's probably no leak. That's good because if it's drawing air into the fuel system it could affect the life of your pump, but it's also bad because it's such a common issue and such an easy fix, and sometimes that fix costs nothing (as in my case).


So there must be something else at play here when it's cold, because I assume the engine starts ok if it's up to temperature.


When it fails to start, does the exhaust smell like diesel? Or if it does fire, is there a lot of smoke at first? This might indicate that there's a restriction in the air intake while it's cold, which would make me think of two possibilities:


1) Sticking throttle valve. There's an air valve in the intake in mine (not sure about the ZD30) and if that sticks in the closed position when cold (maybe a tiny bit of debris on the closing face?) and when it's cold it's sticky? It would need to come out to be cleaned.


2) Sticking EGR valve. This one's actually easy - block the bugger off, the ZD30 does not do any analysis of the EGR flow so blocking it will recover a little more power. It's not legal - but it's bloody hard to find, there are thousands of cars in Australia with blocked EGR valves. It's such a common thing to do that Nissan had to put a flow detector in to stop us from blocking it (I think that first arrived in 2012/2013). EGR is exhaust gas. If the valve is stuck open, when you try to start the engine it will just pump exhaust gas straight into the cylinder and it won't fire properly at idle.

 

[Farmer Joe]

sounds to me as if your new glow plugs aren't working! Have you checked that you have power to them?

 

[benpayne92]

ok, so the weather here today was nice went outside she started straight away no problems,
But when it is cold enough and it struggles to start it does get a big thick white cloud of smoke and a strong smell of diesel for approx 3-4 seconds.
Also EGR is already blocked, and I’ll do some research on the throttle valve thanks mate.

And farmer joe, without sounding like a complete idiot, how would I check if the plugs are actually getting power?

 

[bods]

To test the glow plugs you need a multimeter. There should be a large wire that connects to the rail (the bit that runs across the top connecting them all together) which should have battery voltage at it when the key is first turned on and for a certain amount of time, until the coolant gets to a certain temperature.

 

[benpayne92]

Thanks heaps for your help guys turns out i wasnt getting power to the glow plugs which i found is becuase the fuse is blown, ive had a bit of a look around where do i find this type of fuse?