Audi 5000 Diesel conversion

[Cody Forbes]

> In order to operate the climate coltrol, you'll have to get a special
> vacuum pump, it looks very similar to the Cruise control pump but
> functions a bit differently, I guess the TD does not scavenge (and
> save) vacuum from the intake manifold like the gas turbo systems do.
> You might also need things like a fuel pump (apparently those diesel
> units really crank out some serious pressure) and other trinkets.
> The family album may be of some service in listing parts for the
> diesel engine. Cheers!
> Steve Sears
> 1987 Audi 5ktq
> 1980 Audi 5k
> 1962 and '64 Auto Union DKW JUnior deLuxes

Diesels do not have an air restricting type throttle (the butterfly) like 
gas engines, and therefore do not HAVE vacuum in the intake. Diesels vary 
their engine speed by altering the air/fuel ratio. Leaner causes the engines 
power to reduce to the point when it can't spin itself any faster, richer 
increases the power output and accelerates the engine. The throttle pedal of 
a diesel vehicle is connected only to the mechanical fuel injection pump, or 
in the case of modern engines only to the ECU. A diesel is a variable a/f 
ratio engine. Unlike a gasoline engine a diesel can not suffer from 
pre-detonation (pinging, knocking, etc) because the fuel is injected into 
the cylinder directly at the precise moment of firing.

A diesel does not have an electrical ignition system, so the person that 
said you have to find a tach signal elsewhere was correct. I'd assume its a 
flywheel sensor. You will need to have a glow-plug heating system, which is 
how a diesel starts when below full operating temperature. Once running a 
diesel continues running only by using compression plus its own heat to 
cause the fuel to self-ignite (which is why it's injected so precicely). A 
diesel once running actually needs *NO* none nada electricity to contine to 
run. The fuel pump is mechanical, and the ignition is self sustained as 
explained earlier. This means if you toss an alernator belt halfway between 
Los Angeles and Miami you can continue your trip just fine as long as you 
don't shut the engine off (it of course can't turn the started with a dead 
battery).

You would not need a new fuel distributor as somebody suggested, since a 
diesels mechanical injection pump pumps to each cylinder diectly and 
individually, with direct cylinder injection (like Audi's FSI...only 
invented 80 years ago). All CIS related parts go bye bye. You wouldn't need 
new fuel lines, you just simply need to make a fuel pickup in the tank to 
reside where the pump used to be. You can buy a pickup for use in racing 
fuel cells, then just clamp it to the end of a hose that runs to the bottom 
of the tank. The other end of the hose can go to where the old fuel line ran 
between the pump and tank top lid thingy. You may want to install some type 
of check valve to make starting quicker.


I'll post more on this subject tomorrow (like instructions on how to run 
your diesel on veggie oil for free!!), but I must get going on my road trip 
now.

-Cody Forbes
http://www.5000tq.com
'86 5ktq
'86 5k-t-q
'87 5ktq - Fast.