123 ignition with dual webers

[Tappy]

Hi all

After a lot of husseling with my ignition i'd like to switch over to the 123 ignition system
http://www.123ignitionusa.com/fiat.html

but i'm running old style weber idf 40's(13/15) and it seems the 123 system needs an vacuum connnection , currently i'm running a points ignition with centrifugal advance ....

can someone tell me if there's a way to controll vacuum advance with the webers ? And if its possible, where to hook up the system

thx in advance

[seabeelt]

Search Artique"s carb writeups . I believe there is a vacuum port on the inside face of the carb - towards the engine side at the base of each carb. i think it shows in one of his diagrams. I'm also running 40 IDFs 13/15 but I have Mark's computronix ignition and have the ports plugged off.

[Tappy]

wel seabeelt i've found those idf writeup ,still not sure on the vacuumports nr 19 on de papers ?

i was thinking those ports on the back were for vacuum but can anyone tell me for sure ,? I dont want to end up spending lots of $ and have no working system

[rebar1111]

I have the 40 IDF 13/15 on a 2L with stock electronic ignition. I simply plugged the vacuum diaphragm on the distributor to keep it clean. The carbs don't have a vacuum port for the distributor, but the distributor vacuum control is for better fuel economy. Only the centrifugal advance is needed. The vacuum advance doesn't add any further advance past the 28 deg. Chevy performance Vettes and Mallory had full centrifugal advance and weren't concerned with economy.

The two ports on the engine side base were to be hosed to the air cleaner (turtleback) for fresh clean air supply.

Took a long time to find this out. Hope it's true. It does match the turtleback.

Car runs fine.

[rebar1111]

Now that I wrote the response, it dawned on me that, at least part of the time, those two ports produced a positive pressure implying that the carbs were venting into the AC. In any event the ports should be hosed to the AC.

[majicwrench]

If you have a distributor w a vacuum advance, it really should be hooked up. Better mileage, cleaner oil, cleaner spark plugs, all sorts of good things happen w advance hooked up.
There is no reason you couldn't drill and tap a small hole in intake for vacuum line.

[bradartigue]

Distributor vacuum advance is not there just for fuel economy. Without it connected your acceleration and overall performance will suffer. Period. If you want to run without advance then get a mechanically advancing distributor, such as a Marelliplex (about $600 on the used market I think) or one of the new electronic types the vendors sell or get creative - drill a small hole for a tube into the phelonic spacer(s) in between your carb and manifold. If I ran IDFs I would run two tubes (one from carb 3 and one from carb 4) and T them to the dizzy to smooth out the pulse.

I had a set of IDFs with tubes under the throttle plates but I have no idea any longer what series they were - they were note the IDF13/15 with the PCV ports. Never use those for dizzy advance.