1) 132 doesn't have an vacuum advance system. i have 2 132's and have never seen such a system on 132
2)about LPG. here the price is about 1/3 to 1/2 price of gasoline. there's about 10% power loss when running on lpg. If ignition is set for lpg than there's no power loss on lpg but it tends to missfire on petrol. guess it could be solved but i just can't be bothered... fuel consumption on lpg is about 15% higher than on petrol. about driveability - everything is ok. only time when i really notice the power loss is above 5.000rpm. engine runs as smooth as on petrol. no warmup is needed. perhaps it would be smart to start the engine on petrol on very cold mornings, as -15*c cold. it rarely gets that cold around here so no there's no problem starting the engine on lpg. today was -5*c in the morning and engine started normaly, i usualy let it run for minute or two before i'm on my way. vaporizer never freezes up if there's enough coolant in the system. i have a friend who lives in lithuania (baltic sea) and he runs his lada on lpg and winters can be very cold there. -30*c is quite usual and he says that he never had any problems. also worth mentioning is that lpg is "green fuel" and is a basis for polution tax exempt in EU, so besides being friendly towards your wallet it's also good for the planet.
i'll take a few pics tomorrow and post them here.
The vacuum advance may just be on US spec Spiders. I just assumed it had the same ignition system because the 132 series 2 liter engines were installed in our 79+ Spiders as well as the fuel injection system.
The ignition system on the Spider and 131s (over here) uses a Marelli distributor, GM HEI control module behind a large finned housing that also holds the ignition coil.
Back in the 70s Fiat offered an electronic ignition system called The PLEX which uses no vacuum advance and a large box similiar to the BOSCH system used on X 1/9s.
About LPG and natural gas. That's odd that it's much cheaper in other countries. What country do you live in?
The reason propane and CNG hasn't caught on here in the United States is due to the price compared to petrol. They do use it on allot of lift trucks because it gives off less fumes inside buildings.
Also the price of LPG and CNG usually follows the price of petrol. When one goes up the other one does too.
Some people like to run farm diesel in older diesels because it's taxed less but it's illegal.
One reason I wanted to run LPG was during hurricane season whenever there is a storm predicted they shut down the refineries along the gulf and start using reserves. So the price goes up and people start hoarding gasoline.
Last September they shut down the refineries and I had trouble finding gasoline.
Then the price goughing began:
http://s222.photobucket.com/albums/dd148/turbofiat/misc/?action=view¤t=PriceGouging1.jpghttp://s222.photobucket.com/albums/dd148/turbofiat/misc/?action=view¤t=PriceGouging2.jpgThat $4.99 for 3.79 liters.
The BP up the street had plenty of high octane but no low octane. I wasn't about the pay $.20 extra on the gallon for high octane for my Subaru. But then I needed high octane for my turbocharged Yugo and Wal-Mart had none.
I'm not sure what the price of propane is at the moment but I think it's a bit higher than diesel.
The other issue is our gasoline now contains 10% corn alcohol. Not only do you loose about 5-10% mileage, it seems carburated engines are much harder to start when hot in the summer.