Fuel Curves

[Bruce Robertson]

Hello,

What would an ideal plot of manifold vacuum versus injected fuel
quantity look like? I am still on the job of tuning my Lucas mechanical
injection - last night I measured the fuel curve and it seems a bit dodgy to
me (although my opinion is not very qualified). At low vac the fuel
delivery is high, and it drops very rapidly (and linearly) until it reaches
about one third of its original quantity, and then it changes slope and
linearly decreases until it gets to max vac. This means that about the first
10% of the total vac increase reduces the fuel quantity by about 66%
and the last 90% of vac reduces it by 33% (the two parts of the graph
are both linear of course because it relies on springs to derive the
curve). Does this seem good/bad/otherwise to anybody who knows?

Any comments gratefully recieved.

Regards

Bruce Robertson
Lucas injected Bond Equipe Sufferer - New Zealand