Hi there, I'm using a 2004 Nissan Hardbody 3.0 td 16V as a everyday vechile. The truck started jerking and the turbo boost was gone.
1) I pulled the turbo and serviced (no knock, but no improvement)
2) removed injectors and cleaned them and refitted the same way as removal)

After doing atep 2 there is a loud knock. did i do something wrong?

Any advice?

thanks.

 

Does the Nissan have valve lifters? Maybe one jumped out of the valve and hits the valve cover- had the same with my Jeep.
Did you bleed the injector lines?
Is it a common rail engine? Hopefully you didn't open the injectors if so?
Welcome here on Diesel Bombers! South africa is cool.

 

No it doesn't look like a common rail. I did not touch anything else besides the injectors and yes unfortunately i did open them! if i look at them in general they seem to be in a fairly good condition...just clogged. now the local guys tell me that these are 2 stage injectors and thats why they cannot be calibrated. Personally i think they want to make money off me by selling me new ones. The fuel lines were bled out, so i believe that enough diesel is coming through. Hope these details help!

Thanks,

 

Let me ask you a question.
Do you have a pressure tester to check the spray pattern of the injectors?

If not why have you opened them? A faulty injector will give you a very loud knock.

I need more details.
Is the knock rpm related?
Single or multiple knock or rattle? Try to give more details.
I translate 'jerking' as a limp mode. Therefore the boost is limited. Did you read the fault code?

 

No I don't have a pressure tester. I'm new to the whole diesel mac scene...So call it a bit un-educated/un-informed. That's why I opened them up.

-There where no fault codes
-Before my "mistake" there was no knock
-Knocking occurs at idling which sounds like one massive rattle
-Have not yet established if it's multiple or not

I'm trying to get the injectors tested (@R600 per injector), but like every thing else in South Africa it's expensive. I can buy a tester at half the price, I'm not sure if it's worth it? If I do buy the machine, where would one get the pop specs?

Hope this helps.

Thanks,

 

The problem I have in the moment your engine is relative unkown in the US. You are lucky that I read it- so I asked around in germany.

It is not about the specs- it is the spray pattern. The injectors do have tolerances close to nothing. They need to be installed wet. If you have a closer look the needle slides in the injector just by gravity. If they are assembled dry you ruin them. Because they will be cold welded together.
So this cleaning can be expensive for you. Your only chance is to get them tested. You should know that you might have to replace your injectors.
600 Rand is like 60€- if you can get the results like spray pattern, rattle and release pressure it is expensive, but still ok.
A new injector will cost you an arm and a leg.

Will be in Bots, Gaborone in September to November

 

I have now been told that these injectors are 2 stage injectors and thats why they cannot be calibrated. Suprisingly, the same people that sais this can't tell me what a "2 stage injector is"! Ido understand the operation of an injector, so if the needle, nozzle, etc. are still fine (seeing that the vechile only has 80 000Km on the clock) why can't they be calibrated?

Thanks for all the info,

 

Usually the injectors are shimmed to have an equal opening pressure.
I guess due to the dual stage this is not possible, because shimming influences always both springs.

But to be honest I'm not absoluely sure about that.

Dual stage is easy to explain. Two valve shafts are mounted behind each other and connected via the stems.The stems are working independent. A certain pressure from the pump opens the first lower stage. A small amount of diesel is injected.
This is the so called preinjection, milliseconds later thr Injection pump builds up the full pressure and both valve stems are actuated. The full amount of diesel is injected into the chamber.

The advantage of the staged injection is a smoother, more quiet engine.

Disadvantage is that is engine is fully electronic controlled. It can also be derated just by lowering the diesel amount by the injection pump.

Another disadvantage is complex injectors. I already heard from german drivers(warning! rumor!) that the injectors can give you some trouble.

 

Could you please pm me you e-mail address? I took a photo of the injector and would like you to have a look at it.

Thanks