TDI Roc, updated info and more questions

[scirocco at vintagewatercooleds.com (Eric S)]

Cory, as you can see, peoples opinions differ on this.

Responses inline:

Cory Langford said:
> So from the great responses I have so far here is what I have compiled:
>
> The best engines to source for the swap would be either the AHU or 1Z
> engine from an A3 jetta or B3 passat.

B4 Passat.  TDIs Passats were sold in the USA as 96 and 97 models for the
B4 chassis.  A3 Jettas were 97s and 98s.

> I will need all the engine electronics (obviously) as well as the pedal
> position pot. and the electronics associated with the DBW arrangement.
>
> I will loose all the fuel pumps, etc except for the intake prepump, and
> will need to reroute the fuel lines around the missing equipment.

*Intank* pump, commonly known as the transfer pump, can be retained, and
left hooked up.  It will act as a lift pump, and is quite convienient.

> Stick with a cable shift tranny unless you can build a really strong 020
> :)

;)

> The TDI engine may have clearance issues with stress bars/hood like an aba
> swap??

Maybe no stress bar...not sure.

> Questions that have popped up:
>
> I noticed a few places mentioning a water separator.  Is this something
> that comes with the fuel system of a TDI that I should grab, or is this an
> extra add-on to source?

As Drew pointed out, a diesel fuel filter setup with integrated water
seperator is just fine.

> What about the Tac?  With out a coil to trigger the tac I doubt it will
> work :)  So What options are there for a tac for a TDI?  I also assume
> being a diesel that the red line is very low.

That is something I have yet to sort out myself.  Drew pointed out that
the ECU does supply a signal, and I have heard that someone used a device
from Dakota Digital to change the signal to properly drive our older
tachometers.

> The DBW pedal position pot.  I noticed pictures on the tdi club of people
> using the entire pedal from a TDI.  The pot looks like it is attached to
> the pedal directly.  On the older cars was it in a separate place?

The pot unbolts from the pedal assembly.

> because the injection pump is at such high pressure, I am assuming it is
> mounted to the engine (or close to it) and thus we only have to run lines
> to it from the pick up pump?

Drew pointed out, the injection pump is ON the motor, run by the timing
belt.  You will run lines to the fuel filter/seperator, then from that to
the injection pump.

> Most likely I will have to get a VagCom to reprogram the ECU?  I am
> thinking that the ECU may have issues when it notices that the abs, air
> bags, etc, etc are no longer connected.  Or were there old tdi's that had
> none of these things?

Yes, get VagCom.  Otherwise you will have a hard time diagnosing anything
on this motor.   The older ECUs won't complain about no abs or no airbags,
but they will bitch about pedal switches and the like.  Most of its pretty
easy to fake out the ECU.

Now, good luck finding a motor for a reasonable price...these puppies have
been selling more than 1.8Ts go for.

-- 
Eric
www.vintagewatercooleds.com

1979 Dasher Coupe 2.0 8v
1981 Scirocco S (TDI swap project)
1990 Corrado TDI
1990 Fox Wagon 1.6 Heron Head 8v
1991 Cabriolet (2.0 crossflow 8v project)