how on earth do you tune D22 ZD30

[2greedy]

Hi guy's

How do you tune these things? mine is using excessive fuel and gutless, i have had a 3"mandrel bent zorst fitted, but i can't see how that would improve things without adjusting fuel mixtures, timimg and rail pressure etc....

so how do you change these settings?

 

[Old.Tony]

You change those things with a chip.

If it's using more fuel already, I'd suggest an air intake restriction is causing the problems. In a diesel, there's no butterfly to control the amount of air drawn in - the engine gets a complete lungful every intake stroke. The only thing that varies to change power/rpm is the amount of fuel being squeezed in.

If your air ducts are ok and air filter clean and you still have lots (LOTS) of black smoke when you put your foot down hard, it's possible that at least one or more injectors are not spraying the fuel in, but dribbling it in - so the fuel isn't combusting completely. A tank or two treated with diesel injector cleaner might help there.

There's also a possibility that your CAS has come loose or rotated. This is the sensor that tells the ECU what angle the crankshaft is at, so it knows when to open an injector. Open the injector too late in the cycle and the burn isn't complete as the piston passes the maximum effect point (about 20% of the way down in travel).

 

[2greedy]

Hi tony

that's just it m8 all air system is clean

doesn't blow black smoke only if you load it up from take off, it's gone from 10l's per 100 to 12.9 ?

it's got me stuffed and the worst part of these engines ya can't adjust anything to compensate?

 

[Old.Tony]

The lack of adjustment could just as easily be argued to be one of their best traits - less to go wrong. Diesels are renown for their reliability compared to petrol engines.

If the air system is clean and it's only blowing black smoke on take off I'd suggest that part of the operation is normal.

It's odd that it's using too much fuel. Do you have any figures to give us a rough idea of how much fuel it's using, for example 60 litres gets you 400km?

It could still be injectors underperforming. It might also still be the crank angle sensor that's out. If it's advanced itself and the ECU is pumping in diesel a little too early, your motor will sound a lot louder because the combustion process will start in earnest while the piston is still rising. This results in a major performance loss but, with extra time to burn the fuel, no extra smoke. The performance loss is partially compensated for by a heavier right foot, which increases fuel consumption.

So, I'm thinking CAS. Anyone else?

 

[2greedy]

how is the CAS adjusted tony? or what needs to be done?

 

[d22dave]

What size tyres you running, I changed from 265 70 16 factory tyres to 265 75 16 all terrains and my fuel figures went from 10.2 lt up to 11.5 lt

 

[Old.Tony]

On the KA engine it's actually part of the distributor. The manual doesn't indicate where it is on other models.

I think Dave has the same motor as you. He'd know where it is. The D40's is on the rear of the cylinder block.

 

[2greedy]

@ dave
Tyre sizes are 235/70/16 dave

@tony
the engine is ZD30TD

but the main things that are annoying me guy's is fuel consumption and lack of low down grunt!

this thing doesn't give anything real till about 3200RPM? which is why i put the 3" zorst, and now have replaced turbo with new factory 1 and still wouldn't pull the top sheet off my bed!

and no-one can give me a definitive answer? as to what's wrong? surely these things should be giving more grunt before 3200RPM?

If i take off from a set of lights i always worry bout the vehicle behind me running into my back end it takes off that slow?

 

[Old.Tony]

It definitely sounds like something is wrong. They shouldn't be putting traffic lights on race tracks, that's what it is!

Seriously, it's quite difficult to diagnose these things in text. If I could jump in the car and take it for a drive, interrogate the ECU to see what problem codes are there and what kind of fuel pressures you're getting etc etc it would be different.

However, we keep asking questions and different people come in with different experiences and perspectives and a lot of the time, we get it right. Sometimes we don't, and sometimes we struggle to find an answer. Sometimes that's because it's a new problem, sometimes it's because we don't have all the information.

Let's see what others say as they discover this thread. A faster answer might be obtained from a workshop, especially one that's dedicated to diesel performance, but it won't necessarily be free.

 

[2greedy]

how do i get the codes tony? i have tried before and kept getting 4 figure codes?

 

[Old.Tony]

The codes are obtained by any device capable of querying your ECU. Nissan use a tool called a "Consult II" or "Consult III".

Personally, I have a bluetooth OBD adapter (ELM327-compliant) and a Samsung Galaxy SII phone with Ian Hawkins' Torque application installed which gives me the info I need.

There are hand-held devices you can buy from China, but you could just go to a motor mechanic and ask them to pull the codes out.

Armed with the code, we would know what the ECU thought the problem was. That might lead us to a solution.

Generally, though, codes are only present if the Check Engine Light comes on.

 

[joshman]

I'd start with tyre size. You're running tyres that are 735mm in rolling diameter.

As far as I know, d22's run 265/70. Which have a rolling diameter of 778mm

At 100km/hr they sit at about 3k rpm.

That could have a lot to do with the perceived lack of power. The power may be there, it's just not being delivered in an ideal manner.

 

[2greedy]

yea well there is no check engine light tony coming on at all? but i know something wrong as i can't even hold a 100kmh on a slight incline?

 

[joshman]

The turbo could be another thing to look at. It's almost as though you're not getting much boost.

 

[tweak'e]

Hi guy's

How do you tune these things? mine is using excessive fuel and gutless, i have had a 3"mandrel bent zorst fitted, but i can't see how that would improve things without adjusting fuel mixtures, timimg and rail pressure etc....

so how do you change these settings?

its not common rail so theres no rail pressure.
theres no adjust fueling short of chipping it.

this thing doesn't give anything real till about 3200RPM? which is why i put the 3" zorst, and now have replaced turbo with new factory 1 and still wouldn't pull the top sheet off my bed!

and no-one can give me a definitive answer? as to what's wrong? surely these things should be giving more grunt before 3200RPM?

thats fairly normal, they are under fueled in the low rpm so there not much till the 3k-3.5k power band. need to chip it to fix that.

biggest thing with fuel usage is how you drive.

if your doing the exact same route and same speed then you can get a good idea of fuel usage.

common problems are egr stuck open, possible problem with turbo waste gate, loose intake hoses, blocked up intake, worn injectors, blockup fuel filter.
one BIG thing is just crappy fuel.

really need to know things like boost pressure, egt temps, what speed your driving at, what other mods have been done, when was oil change last done, any smoke (be honest!) etc.

 

[2greedy]

@tweak'e

Hi tweak
the turbo has just been replaced and i have installed a boost gauge and manual boost controller, boost level is 15psi adjustable to 20 but makes no difference?

have fitted 3" mandrel bent exhaust, snorkel,oil catch can, egr mod

would chip it but i don't see the sense in spending $1200+ on something that has $50 worth of parts! it's just daylight robbery! i have studied electronics and know for a fact there is no more than $50 worth of parts in those chip modules!

 

[joshman]

Get the injectors cleaned?

 

[2greedy]

yes i think i will do that first josh i did run some cleaner through it and it has improved things but i think the cleaner isn't working good enough?

thinking maybe injectors too dirty for normal cleaner to clean.

 

[joshman]

Mmm, sounds likely. If I've got time over the Christmas break I'm going to pull off my intake manifold and give it a clean. And in the new year, give the injectors a birthday. Apparently it makes a MASSiVE difference to the vehicle.

 

[tweak'e]

@tweak'e

Hi tweak
the turbo has just been replaced and i have installed a boost gauge and manual boost controller, boost level is 15psi adjustable to 20 but makes no difference?

have fitted 3" mandrel bent exhaust, snorkel,oil catch can, egr mod

would chip it but i don't see the sense in spending $1200+ on something that has $50 worth of parts! it's just daylight robbery! i have studied electronics and know for a fact there is no more than $50 worth of parts in those chip modules!

more boost will not increase power. it has a ton of air at 15psi, what it needs is fuel.

really need to know what sort of speeds your driving at and also your math for the fuel consumption. sorry but seen it way to many times where its just a math error.

it could simply be an increase of outside temps as we go into summer.