71 automatic fastback: Horrific fuel consumption

[Slow 1200]

So, I have an all stock euro-spec automatic fastback, which means it's running 32-34 PDSIT Solexes, the car has only 50.000km (30.000 miles), so engine shouldn't be tired, it was stored for 20 years, so that could be an issue, carbs and distributor were refurbished, points, condenser, plugs, wires, fuel pump (cheap brazilian) are all new, valves are adjusted.

The distributor is a dual vacuum advance-retard one (stock for the car) but I have disabled the retard part, plugging the hose (not the canister), I set the advance with vacuum off so the centrifugal part would go to 32º max, which is around 10º at idle vacuum advance connected. (at first I had it at 7.5 but that had a little of an off-idle stumble)
The acc pumps in the carbs are set for minimal discharge, and the idle mixture is set quite lean (emissions testing the other day revealed an idle CO of 0.6% which I recon is even probably too low for proper combustion with stock ignition)

The problem is that fuel consumption is terrible, first tank was gone in less than 200km (so over 20liters/100km), second one (after the advance change and tweaks) yelded a slightly better but still non acceptable 17,5 l/100km (I think thats about 13mpg)

Some known issues with this engine are worn throttle bodies (like every other PDSIT on earth) and kinda high blow-by (probably stuck rings from seating so long?) but still, I don't see where is all this gas going, chokes are opening as they should, I guess I should check fuel level, I've read that PDSIT rebuild kits come with questionable needle and seats and washers, but I can't think of anything else, any ideas?

car drives ok, only a random stumble off idle when hot now and then, definetely not a powerhouse but I can get it to 110kmh with reasonable ease (engine would go higher but haven't tried yet)
have looked for fuel leaks but didn't find any!

[Slow 1200]

Ok, I did some investigation today, turns out the vacuum advance canister had a slow leak, luckily I had a spare 71-only euro-spec distributor that still has a good vacuum advance diaphragm (retard is shot, but I can live with that)
I also changed the needle and seat and now I'm running the original solex ones, they were actually a little bit longer, so that should give me lower float level, tried to measure it but I had spilled gas so that was worthless, in any case, I can't go wrong with the originals!
car drives roughly the same, we'll see how it goes next time at the gas station

[Slow 1200]

ok, this time it averaged 13,4liters/100km (17mpg), and that was roughly half of the tank before the needle & seat change, half after, so it seems I'm on the right track, we'll see how the next tank goes

on another note, the car lost all power suddenly in the highway....turns out somehow the + wire worked its way out from the coil! all was well after that

another thing I have to figure out is the auto trans shift points, the kickdown let's the engine rev way too far and keeps downshifting at too high speeds, I guess I can adjust the vacuum modulator?

[Piledriver]

check for vacuum leaks first--- In fact, if you see any rubber hose, ANYWHERE, be it fuel, vacuum or vapor vent, replace it NOW.

They are all krispy like toast, even if they look new.

This probably includes the "sleeves" on the metal bits for the filler hose (if so equipped)
The filler hose itself is probably OK.

[Slow 1200]

every hose in the car is one year old at most, the only known intake leaks are the (of course) worn throttle bodies in the PDSIT carbs, I will recheck the vacuum line to the modulator anyway just to be sure it's not leaking

[Piledriver]

Glad to hear it, there has been more than one car-b-que from old hoses, and many near misses.

Sounds like you may have read the "how-not-to-burn-your-car-down" threads!

You may need to change your oil (more) frequently at first to help clean her up.

[Slow 1200]

yup already changed the oil 3 times, comes out like black sludge every time !