ZD30 blowing smoke

[flatout]

Hey Guys

My ZD30 Nav is running a little rough and blows a heap of black smoke when under load eg fast acceleration , towing up hills etc but is still only using about 9.5L / 100kms under normal driving.

Has only done 128000kms.

Any thoughts on what might be causing the issue ?

 

[gadgets]

Try running some injector cleaner through it, maybe an engine oil flush too.
Might be some bad fuel, change the fuel filter too and see how you go.

 

[Steedjo]

Black smoke is unburnt diesel/ Not burning the diesel efficiently. Injector cleaner, fuel filter would be the cheapest place to start, like gadgets said.

 

[tweak'e]

has it been chipped?

if its stock then it must have a big inlet restriction or injectors need replacing.
what boost and egts do you get?

 

[flatout]

I was initially thinking injectors but I would have expected fuel economy to have deteriorated.

I've been running Caltex Vortex Diesel which apparently has a detergent to clean the injectors.

Car is 100% stock. Doesn't have a boost or egt gauge installed as yet.

New airfilter has also been installed. Turbo is only about 10000kms old.

One thing I did notice a while back is when idling it had positive pressure (I assume from the breather) coming out the join in the airbox which made a whistling noise which when away when I sealed it up. Is this normal for a ZD30?

 

[joffo81]

I have also noticed air coming out of the join where the airbox closes. Not sure whether its normal or not. How did you seal it? It can't really be glued cause it needs to be opened to repace air filter. It seems unusual to me because I would have assumed that a poor seal in the air box would cause air to be sucked in not blown out.

Can anyone explain this?

 

[Dave]

What they all said.

How's the air filter ?

 

[Steedjo]

I have also noticed air coming out of the join where the airbox closes. Not sure whether its normal or not. How did you seal it? It can't really be glued cause it needs to be opened to repace air filter. It seems unusual to me because I would have assumed that a poor seal in the air box would cause air to be sucked in not blown out.

Can anyone explain this?

Ive been going around this week trying to get an O ring for the exact same reason. Cant find one anywhere. What im about to try and do is get some silicone on some baking paper and try to make a seal. Once its dried it should seal nicely.

 

[joffo81]

Steedjo - let us know how you go with the seal.

Flatout - how did you seal yours?

 

[flatout]

I used a thin strip of adhesive backed foam to seal the airbox.

 

[tweak'e]

do you have egr blocked off?

if not, a stuck egr valve can cause black smoke at full throttle. easy way to tell is to block the egr off.

 

[flatout]

No egr mods.

I thought about that too but had my mechanic put it on his diagnostic tool and he said the EGR valve showed up as working fine and the engine efficiency and emission were very good.

When I had my old turbo at the turbo specialist the first thing he said was it had been running hot as the exhaust housing was really clean and bright and not the usual dull rust colour.

Still makes me think it fueling related.

Do Navara ZD30 engine have boost sensor issues?
Also what are the symptoms of CAS and injector timing issues?

 

[tweak'e]

dosn't rule out egr.
there is no egr position sensor so ecu has no idea if egr is stuck. there is no way to test for it.
i would just blank the egr off, only takes a few minutes to make a plate and fit it.

could be retarded timing tho i would have expected timing error code and poor fuel consumption.

 

[flatout]

I have plans to blank the EGR, install intercooler and egt sensor but wanted to get it running properly in standard form before I start the mods.

Would stuck EGR result in higher exhaust temp?

 

[tweak'e]

Would stuck EGR result in higher exhaust temp?

yes, by a rather large amount.

 

[flatout]

Can the egr be blanked without the solenoid mod?

 

[joshman]

Can the egr be blanked without the solenoid mod?

Yes, but you'll be choking your engine at certain rev points, and would most likely be worse off for performance.

 

[tweak'e]

Can the egr be blanked without the solenoid mod?

for testing purposes no problem.
however long term it posses an issue. the butterfly block air flow so you get lower effective compression and may have some drive ability issues especially when cold, worse case blow white smoke.