1.6D to 1.6TD - change nozzles as well or just cracking pressure?

[TimpanogosSlim]

Hey, i've searched but it's not really been clear to me: When converting from NA to turbo, is there a large advantage to changing the nozzles in the injectors, or is that more in the realm of performance tweaking than necessity?

If i do need (or should want) different nozzles, which are recommended?

What's the recommended cracking pressure when i take my injectors to the diesel shop?

[vwroadkill]

well there are options...I will share what I did.. I took my injectors to the shop and had them raise the pressure to 155 bar... with new nozzles installed total cost was $212 dollars.. this included new nozzles and the injectors guaranteed for one year
the where cleaned, adjusted. the returns were staked. and  painted .
don't know whats near you for this service.. but its what I did

[TimpanogosSlim]

There's a guy semi-local who is looking to get rid of all of his remaining mk1 diesel stuff.

Includes a good hood in orange, what looks like five or six pounds of assorted relays, one rabbit bumper end piece, partial diesel engine gasket kit, and sixteen different IDI injectors, he says some are 1.6 some are 1.9 some are NA some are turbo.

he wants $100 and i basically don't want to drive to where he is and come home with a spare hood.

Maybe i should go for it anyway.

[TimpanogosSlim]

Perhaps i should have asked, is there a major difference other than cracking pressure between 1.6d, 1.6td, 1.9d, 1.9eco, and 1.9td injectors?

did 'gtd' injectors have a different nozzle?

This is not an all-out performance build so i am trying to keep the budget under some semblance of control.

[burn_your_money]

It's not a simple answer. Some of the nozzles used in the original injectors are not available from Bosch so sometimes shops have to make due with what is available. Bosch changes nozzle numbers randomly it seems and they don't say why, or give a lot of details about their specific nozzles. I suspect emissions and noise are the main reasons for them changing nozzles, not power. 

Generally all 1.6 injector nozzles are the same. They can be interchanged safely. I have no idea about the 1.9NA but the 1.9TD (AAZ) is different and is NLA.

[TimpanogosSlim]

OK, so perhaps i just take my injectors to a local diesel shop and have them rebuilt for 155bar cracking, but perhaps i should have some spares on hand?

[745 turbogreasel]

Usually the nozzles seem to be pretty wore out.

[Mark(The Miser)UK]

What's wrong with your current injectors [nozzles].
 If they spray well, and are old French ones then renewing for the sake of it, is likely a downgrade.

Check balance of leak-offs by isolating returns from pump, and running engine for a short time.

 Break pressures almost unimportant, beyond altering timing to suit, and matching them for best results.

[vwroadkill]

are you going to be running a turbo pump?... as explained to me. the pump of a turbo puts out a higher pressure{ somebody here can chime in on this}. the crack pressure 155bar.. works with the turbo pump.. using 130 bar injectors makes the timing earlier on the turbo pump, if I recall correctly.
now I did mine for the sake of a daily driver... new nozzles are not expensive.. I believe I payed 84 dollars total for the nozzles. the rest was labor and time spent making them equal...hope this helps

[TimpanogosSlim]

are you going to be running a turbo pump?... as explained to me. the pump of a turbo puts out a higher pressure{ somebody here can chime in on this}. the crack pressure 155bar.. works with the turbo pump.. using 130 bar injectors makes the timing earlier on the turbo pump, if I recall correctly.
now I did mine for the sake of a daily driver... new nozzles are not expensive.. I believe I payed 84 dollars total for the nozzles. the rest was labor and time spent making them equal...hope this helps

Yes. I have a recently rebuilt 1.6TD pump that has an AAZ cam plate in it.

So i am under impression that it behooves me to have them shimmed to a cracking pressure of 155 bar.

I have no experience with this engine and the guy i bought it from had little experience with it. The guy he bought it from really knows his way around vw diesels but I've never spoken to him, and he's left the country.

I bought the car in a non-running configuration and all available evidence points to worn rings, but I have yet to pull the engine. Hoping to get that done this weekend.

[Mark(The Miser)UK]

Easier to check engine whilst still complete and in the car...  Compression test for instance.

Differences between nozzles over the years were in the presquirt:
Seeking faster  burn of main injection, lower noise, reduced detonation.
 Parallel pintle, tapered pintle  champhered pintle, then AAZ parallel pintle, but with notional adjustable delay before main squirt.

VW then pretended not serviceable by mere men, other than by exchanging. Complete and utter nonsense IMO. I may write up a thread about these dual spring things.
GTD nozzles? Well I've never had them out of my GTD, but I suspect that there is not much difference from TD.

Further improvements could have appeared, but stymied by TDi introduction. High pressures of TDi nozzles is because the fuel has but small time to search out the fuel. IDI's great advantage is that the air swirl hunts down the fuel, and tears it apart, and can cope with a wide range of droplet size,  and fuel type. Ceramics probably could have been an improvement as well as a cast iron head with it's 1/4 of aluminium's conductance

[burn_your_money]

the pump of a turbo puts out a higher pressure{ somebody here can chime in on this}. the crack pressure 155bar.. works with the turbo pump.. using 130 bar injectors makes the timing earlier on the turbo pump, if I recall correctly.

The NA and the TD pump are capable of putting out the same pressure. You are correct that having 130 bar injectors advances the timing slightly.

[TimpanogosSlim]

Easier to check engine whilst still complete and in the car...  Compression test for instance.

Seller informed me that it had got to a point where it would only start when towed, and could not stay running.

Cold compression test revealed very low compression across all 4 cylinders. Putting oil in the cylinders improved compression somewhat.

He commenced pulling the engine, then decided to sell and partially reassembled.

It was not his first rodeo - he's a friend of a friend and i am aware of his level of experience and have no reason to disbelieve what he's told me.

So i paid $500 for an 84 jetta coupe diesel with an excellent interior and rust that isn't terrible, that reputedly needs a bottom end rebuild. Or at least a ring job.


. :Sent by pneumatic tubes

[Mark(The Miser)UK]

Easier to check engine whilst still complete and in the car...  Compression test for instance.

Seller informed me that it had got to a point where it would only start when towed, and could not stay running.

Cold compression test revealed very low compression across all 4 cylinders. Putting oil in the cylinders improved compression somewhat.

He commenced pulling the engine, then decided to sell and partially reassembled.

It was not his first rodeo - he's a friend of a friend and i am aware of his level of experience and have no reason to disbelieve what he's told me.

So i paid $500 for an 84 jetta coupe diesel with an excellent interior and rust that isn't terrible, that reputedly needs a bottom end rebuild. Or at least a ring job.



. :Sent by pneumatic tubes

So it's quite bad then .

In my last comment for the TDi read "fuel seeks air", not "fuel seeks fuel; else we are talking magnetic fuel, or planetary sized globules, sorry LOL

When you pull the pistons, visually inspect each big end bearing and if unmarked, do a Plastigage check.
When you remove the pistons, try and get the compression rings off without breaking and drop them into their positions in the bore.
 
Note the size of the ring gap, then note the actual reduction in radial diameter of the rings.
Compare with the correct thickness of a new ring...
[ I can't remember the size at he moment, but by doing this you can see if new rings will close up the gap enough to add 200psi to your compression and avoid reboring, oversizing etc.. ]

[TimpanogosSlim]

I'll try to do that.

It's likely that I'll end up having a machine shop check the bore. If only because the friend who will be mentoring me through the rebuild is the engine assembler for an excellent machine shop. It may be impossible to talk him out of just taking it to work for me.