[Vwdiesel] 1990 Turbo diesel Fox 2 dr Wagon

[Stephen Kraus]

I thought the opposite was true, I thought HIGHER compression made it
easier to start in the cold.

In fact, that is one of the troubleshooting points if your car starts hard
in the winter: Check your compression!

On Wed, Apr 18, 2012 at 1:00 AM, Brian and Ruth Decker <decker at toledotel.com
> wrote:

> Hi Folks;
>
>                I got busy so the Turbo Fox project was somewhat delayed. I
> rebuilt a 1.6 turbo diesel engine that I had bought at an auction. It must
> have been from an Audi or Quantum and had an automatic. Through the years I
> have wondered why our 1.6 diesels had 23 to one compression and wondered if
> they might run better with slightly less compression. Where I live in
> Western Washington it doesn't get incredibly cold so I felt perhaps
> starting
> with less compression might not be impossible. The block has 1mm over
> pistons.  I took them to my machinist and he took enough off the tops of
> the
> pistons to take out about one half of the swirl chambers. I reassembled it
> with all new bearing, seals and a 3 notch head gasket (the thickest
> available). We were guessing we might have about 20 to 1 compression. We
> put
> new exhaust guides in the head plus new valve seals and lapped the valves.
> It has a rebuilt injection pump and rebuilt injectors. It also has a two
> and
> a half inch exhaust system and a turbo Quantum 9Q 5 speed tranny.
>
>                Now the fun begins. We set it up using the recommended pump
> setting from our Bentley. The engine started somewhat hard and truly wanted
> the cold start pulled. After warming up it ran pretty strong but was
> getting
> about 32 mpg. I then started fooling with the idle settings and the fuel
> screw. I have a pyrometer so was careful not to get the exhaust gas
> temperature too hot. I could get good power but mileage didn't improve.
>
>                I finally decided that since I have lower compression than
> stock perhaps stock settings weren't what the engine needed. We upped the
> pump timing to 1.10 and  it ran better, started  better and the mileage
> improved. We now are at 1.30  and the Fox wants to run hard, fast and the
> EGT's are good. It loves going down the freeway at 70-75 and would happily
> cruise faster if I wasn't afraid of the law. The mileage is around 45 mpg
> running hard and fairly fast. We pulled the injectors today and did a
> compression check and all cylinders are very close to 360 lbs. For some
> reason it just loves lots of injection pump advance.
>
> Brian Decker
>
> Toledo WA
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