DJ engine related questions - prep.

[Smiffo]

All.

Currently have a 1.9 DG petrol and longer term will be acquiring parts to uplift to DJ.
I have what may seem like some odd questions - hoping some "wisdomous" people can fill in the blanks for me.



1. Is there a concise list of items needed to convert somewhere ?
So far I have the engine bay loom on its way, and I can see other items in this good guide:

https://syncrosport.com/info/manual/VW_ ... nj_Ign.pdf


2. Is anything on my DG able to be used? ( I'm thinking Dizzy, but maybe other bits )

3. I don't want to change out a perfectly good engine until needed, so lets assume I have all the injection related items - the question is can I just install that over a DG, so that when I am ready the engine is just a straight swap out?

4. The ECU's seem to come in 2 formats. Part numbers ending E or F. The E variant seems to be automatic - I assume that shouldn't be used on a manual, or is the difference marginal only and insignificant?

I should add, I have factory PAS - guessing that would be involved somewhere in the considerations.

This is going to run on for a while I'm sure, and there will no doubt be dumb questions from me!

[Aidan]

2. DJ disi is specific as it it different internally and has a dual port vacuum unit
3. most people keep the carb etc. when they do a 2.1 swap because it is simpler, easier and cheaper, but it's a bit of a compromise, if you run on lpg it is less of a compromise as the carb is basically just a throttle body
4. you want the manual ECU suffix F or later version 025 997 021  X 
PAS - switch on pump plugs into the loom just like it does on your existing 2E4 DG set up, if you have factory hydraulic power steering

I personally would only do the swap for a complete working known good DJ, but I'd rather run a MV really, on supermarket fuel timed at 5' there is very little between the engines I think

[Smiffo]

2. DJ disi is specific as it it different internally and has a dual port vacuum unit
3. most people keep the carb etc. when they do a 2.1 swap because it is simpler, easier and cheaper, but it's a bit of a compromise, if you run on lpg it is less of a compromise as the carb is basically just a throttle body
4. you want the manual ECU suffix F or later version 025 997 021  X 
PAS - switch on pump plugs into the loom just like it does on your existing 2E4 DG set up, if you have factory hydraulic power steering

I personally would only do the swap for a complete working known good DJ, but I'd rather run a MV really, on supermarket fuel timed at 5' there is very little between the engines I think

Thanks Aidan.

ref the last line there.... Did the MV use Digifant, or Digijet?
Also, why do you prefer MV?
 

[Aidan]

MV is Digifant, lower compression so less stressed engine, slightly cleverer engine management, less mechanical, easier to get new parts for, and more tolerant of fuel types, but it is only 95hp from the factory, but with slightly cleaner emissions

but DJ quoted 112hp was on 4 star leaded fuel running 10' timing, but now if you want anything like that then you should run super plus petrol

[Smiffo]

Many thanks, Aidan. Much appreciated.

[ajsimmo]

I agree with Aidan, mostly. Except that I love the DJ on LPG, which is higher octane than Super Unleaded and will tolerate the extra advance. I also run mine on super, or add an octane booster to get the advance for the extra oomph.

One thing to remember to check when converting (BEFORE you fit the DJ) is that your RHS head (cyl 1&2) is drilled for your PAS mounting bracket bolts! If it's been rebuilt before and some numpty fitted undrilled DG heads, and you didn't spot it before fitting you'll be spitting feathers - don't ask .

Sent from my moto g(30) using Tapatalk

[Smiffo]

I agree with Aidan, mostly. Except that I love the DJ on LPG, which is higher octane than Super Unleaded and will tolerate the extra advance. I also run mine on super, or add an octane booster to get the advance for the extra oomph.

One thing to remember to check when converting (BEFORE you fit the DJ) is that your RHS head (cyl 1&2) is drilled for your PAS mounting bracket bolts! If it's been rebuilt before and some numpty fitted undrilled DG heads, and you didn't spot it before fitting you'll be spitting feathers - don't ask .

Sent from my moto g(30) using Tapatalk

Appreciate the info AJ.

Just for clarity - on one of my my earlier questions - if I had all of the injection related items, ( Digijet or Digifant ) would it be viable to replace my carb setup with that initially, installing it directly over my existing DG?

I suppose I am asking if the displacement difference between 1.9 and 2.1 would impair the electronic's ability to efficiently run the 1.9

I know some historic 1.9 versions were out there ( Thinking DH or GW ) and they are injected 1.9 litre variants.
Were the ECUs the same, or were they 1.9 specific?
 

[ajsimmo]

It'll run just fine. For a given throttle opening the smaller displacement will shift slightly less air, and the afm will open slightly less as a result, therefore fuelling slightly less. It just knows. Clever, eh?

Sent from my moto g(30) using Tapatalk

[Smiffo]

It'll run just fine. For a given throttle opening the smaller displacement will shift slightly less air, and the afm will open slightly less as a result, therefore fuelling slightly less. It just knows. Clever, eh?

Sent from my moto g(30) using Tapatalk

Indeed it is


Sent from my iPhone using Tapatalk

[Smiffo]

Progress on items sourced:

1. Engine bay wiring loom
2. Idle Speed Stabilising Control Unit
3. Servo assisted steering pressure switch
4. Fuel Pump relay ( goes in black electrical box with relay fixings inside )
5. Current Supply Relay ( also goes in black electrical box )
6. DIS Switch Unit for Idle Speed Stabilisation (?)
7. TCI-H Switch unit ( and heat plate )

I'm assuming an ordinary coil fitted to a DG would suffice.

Parts to source:

1. Fuel Pump
2. ECU 025 905 021 F ( For manual )
3. Distributor ( I'm confused which one will be needed - help required - 025 905 225 N I think? )

4. Then air filter and air flow gubbins:






5. Then all this which I think I have sourced:











The Unknowns:

Coolant hoses - currently have DG with Pierburg. I suspect as coolant goes through the choke mechanism then I doubt there is a similar on the injection aspects - probably going to need to look at that too.


Did I miss anything?
 

[Robsey]

There are a few extra hoses on the DG compared to the digijet.

The DG has hoses to the manifold stubs -but the injection set-up does not.
Best bet is to simply put in a link tube to join the two manifold stub hoses.
And for the auto-choke - maybe just plug the end of the "spare" hose.

[Smiffo]

There are a few extra hoses on the DG compared to the digijet.

The DG has hoses to the manifold stubs -but the injection set-up does not.
Best bet is to simply put in a link tube to join the two manifold stub hoses.
And for the auto-choke - maybe just plug the end of the "spare" hose.


Now then - ECU temperature sensor 2. If you are using an early water-pump and thermostat, you will not have provision for the coolant sensor.
But you could fit this in the cross-engine tube where your current manifold heater thermo-switch resides.
M12x1.5 (fine thread) on the sensor.

I have just drilled my thermostat, and will tap it later.
A la DH set-up style.



I don't have a cross engine tube, so will be making my own up in due course.

Ah - just checked - you have the later set-up, so no concerns regarding the temperature sensor.

Nice one Robsey.

Yeh, I have late cooling system, so I'm safe there.
 

[maxstu]

Dare l mention fuel injection fuel tank? Is it really needed?

[Smiffo]

Dare l mention fuel injection fuel tank? Is it really needed?

Good point Stu. I'm not sure how vital. Perhaps you'd get fuel starvation or something without it?

E D I T: And now I am thinking the throttle cable would need to be changed too?

[maxstu]

The more teccy contributors will likely give you the answer.
But the FI tank does have a larger diameter feed pipe to the fuel pump and a swirl chamber, or a larger swirl chamber, than the carb version.