Wow, that seems somewhat severe damage for just adding 1 litre of petro in
with diesel. If the injectors and pump shredded like that, I am surprised
you didn't have piston damage as well. Here in the U.S., the pump nozzle
sizes are different for petro vs. diesel with the diesel nozzle being bigger
so it is virtually impossible to put diesel in a petro tank but not so
impossible to petro in a diesel tank.

Trust me, they lied to you. My wife put a half tank of gasoline into her '81
300D and drove it more than 50 miles before she suspected something was
wrong. In fact at that point the car simply wouldn't go much past idle. I
took my car carrier to the donut shop where it stopped, started it up and
drove it onto the trailer. Got home, pulled the fuel filter and noticed a
small problem....gasoline in the fuel!
After explaining to my wife that a green nozzle at the service station
doesn't necessarily mean diesel, i drained all the gasoline out, poured in
10 gallons of diesel, changed filters, pumped the hand primer pump for about
5 minutes, started it up and it has run perfect for more than two years now.
Also, I now burn altered veggie oil in both my 240D and 300D and they both
run perfect. I tried the formula sold by Diesel Secret but discovered all
the secret turned out to be was fuel stabilizer.
Here's what you do: To your filtered waste veggie oil add 10 percent low
octane gasoline, 5 percent kerosene, about 1-1/2 ounces per gallon of Diesel
Kleen (Wal-Mart) and about 1/4 ounce of fuel stabilizer (also Wal-Mart).
Make sure you let the veggie oil settle a couple of days to get water and
other debris to the bottom of your container(s). Draw off the good oil on
top and do your mixing. I have a 55-gallon drum with a large funnel-shaped
bottom which I made and welded into place with a valve at the bottom to
drain the junk.
After mixing your veggie oil and the additives pump it through three
filters, two of which are simply water filters you get at your local Lowes
or Home Depot. The first one needs to be about 15 microns, the second 3 to 5
microns and the final filter is a water trap. You can actually pump this
mixtire directly into your vehicle.
I know there are going to be people who say you need to go through the
lengthy process with lye and acid....and you can if you wish. That does
remove a lot of stuff that some think are less than good for your engine.
However, I hasten to remind the naysayers that Dr. Diesel designed his
engine to run on pure peanut oil, and that it works fine.
A couple of other things to take into consideration. Be prepared to change
your glow plugs after going through a tank or two of this mixture. Also, if
you live in a cold climate you might consider a two-tank system allowing you
to start and stop on regular petrol diesel. Whenever I face an early morning
cold start I just shoot a small amount of starter fluid into the intake of
the air filter. Some will think you crazy for doing this but I was raised on
a farm and we always used starter fluid to start our tractors in the dead of
winter even though we used nothing but petrol diesel.
Other than that recognize that veggie oil is a much better solvent than
standard diesel and will clean your fuel system like crazy. Keep spare fuel
filters on hand during the initial tank or two.
Been doing this for some time now and everything works fine. Good luck.

Have a look at some of the discussions in the Citroen section. Veggie oil
is discussed at length. I have a friend with 1981 250d (i think) who uses
nothing but veg oil in all weathers (UK)but in Devon  so it doesnt often
drop below freezing point but if it does he just adds white spirit. The
biggest problem is not how well the car runs but what happens if ther
police/customs & excise find out! By the way DONT use veg in an HDi, the
"old style" diesels are much better