Diesel car intake modifications questions

[scissorhands]

I hope my new Nissan AD with CD17 engine questions, is okay here.

Its really lazy and has only bottom end torque when I bought it recently.

Checked the fuel screw on the pump and a clean air filter. The intake pipe from the air filter assembly to the intake has a diversion that goes to a big deadend box of around 1.5 liter capacity that I believe is called a dust collector. The exhaust header is short and the exhaust pipe is small at 36mm (compared to a Toyota 2C diesel van pipe at 45mm).

The drivability is like a lump of lard, compared to the Toyota 2C, but engine intake and exhaust design seems like a governed or choked motor in comparison.

I pulled of the intake hose as seen sitting on the battery, and put on a pod to see if any restriction occured due to the inline dust collector. When I looked inside the intake manifold the who;le thing was covered with a buildup of carbon, all the way to the valves most probably. I have no clue as to why this happens but I'm no mechanic.

I went out to Piha and thrashed it like this, and I think i pulled a lot of that carbon into the engine at sustained high rpm. The next day it seemed perkier.


I'm really wondering what i can do to improve/raise the torque curve and mitigate some of the inherent governed power characteristics, and lengthen the time through the gears slightly.

I was thinking of dripping a liter of water through the running intake manifold. I have done this before with a pillow case around the exhaust end catching all the carbon that the water and steam dislodges.

Or any ideas on dealing with the carbon build up and why it has occured.

Thanks for any ideas on tweaking the ultra generic company car, with engine highly governed, super econo tuned, and super longevity tuned set up intake and exhaust.

[SMOKEU]

Put a T25 on it with an external wasty.

[Motu]

You have a non turbo diesel,you will have to row it through the gears at WOT everywhere - look at it as a new driving style.The dead end chamber in the intake is called a Helmholtz resonator and is used to help cut intake sound - I bet it made a shit load of noise with the pod.You won't increase power on the intake side of things.You have an EGR valve,that is what causes the intake deposits,disconnect this by blanking with a plate.A better exhaust can help,but is an expensive 2hp.Leave the max fuel screw alone.Best thing to do is to get the injectors overhauled,and then check the injector timing with a DTI.

[Kickaha]

Best thing to do is to get the injectors overhauled,and then check the injector timing with a DTI.

From personal experience this can make a huge difference

[scissorhands]

You have a non turbo diesel,you will have to row it through the gears at WOT everywhere - look at it as a new driving style.The dead end chamber in the intake is called a Helmholtz resonator and is used to help cut intake sound - I bet it made a shit load of noise with the pod.You won't increase power on the intake side of things.You have an EGR valve,that is what causes the intake deposits,disconnect this by blanking with a plate.A better exhaust can help,but is an expensive 2hp.Leave the max fuel screw alone.Best thing to do is to get the injectors overhauled,and then check the injector timing with a DTI.

I ditched the pod today, and have gone back to the standard intake hose,thanks to you for the low down on the Helmholtz resonator.

I sprayed about 1 litre of water through the intake manifiold, high revving over 90 seconds...thought I fucked the engine as all this blue smoke that then happened... pulling spluttering and missing....then remembered oil in intake manifold from camshaft cover top hose getting washed off by the spraying water and getting burnt... also alot of the carbon has been washed/sucked off from inside the intake and combustion area and exhaust headers.

After the internal steam clean the engine is perkier still. Getting better

I will run an additive for the next 3 tanks. Prolly just need to accept its a lazy engine compared to the 2C Toyota. Will fork out for injectors and timing if I cant work any more tricks

Anyone know if EGR valve blanking plates are available for the CD17 engine? Or do i need to make this and get a large bung for the exhaust manifold end

Has anyone tried the internal steam clean before? I heard auto trans oil can be dripped in for different cleaning?

[Motu]

A diesel engine burns oil,any oil - you can't clean an intake system that way,it just runs on the stuff.The only way to clean it is to remove and soak.I have made a hot dip tank at work to clean diesel intakes - modern common rail diesels glog intakes even more than the old ones.Block the EGR,and run the breather through a catch tank to remove oil....that is what causes the deposits.But if the EGR is blocked,then the oil from the breather will just go though and burn.