vacuum advance

[mcericmc]

I have a 1974 914 with a 1.8 liter engine. Someone had deleted the vacuum advance on the distributor before I bought it. I have some questions... First, how important is it and why would someone remove it? Second, is it possible that it was replaced with a centrifugal advance and how can I tell if it is and third, can I replace the points with an electronic ignition if it doesn't have vacuum advance? Thanks in advance for some help.

[Dave at Pelican Parts]

What do you mean by "the vacuum advance"? Do you mean the whole dashpot (the silver vacuum gizmo on the side of the distributor), or just the advance fitting on the dashpot?

Most 74+ 914s did not have vacuum advance. They did, however, have vacuum retard. So they had the dashpot on the distributor, and only the retard fitting was hooked up to a vacuum source. (The advance fitting usually had a hose on it that ran to nowhere so people didn't freak out about a bare fitting.) The throttle body on those cars was not drilled for the advance fitting, but I presume it was cheaper to keep using the same dashpot rather than have a separate one without the advance fitting on it.

If yours is like this, it is perfectly normal and you can use any points-replacement gizmo that does not foul on the vacuum actuation arm inside the distributor. I think I remember that the Pertronix unit with the "V" suffix is one that makes room for this. The earlier one without the "V" requires some careful trimming of either the magnet ring or the distributor rotor (or both) to accommodate the arm from the dashpot to the points plate.

Since the 1.8's L-Jetronic fuel injection does not have specific "trigger points" in the distributor (which D-Jet has), it is possible to replace the whole distributor with a centrifugal-only distributor. If your distributor has no dashpot, then check around it for part numbers and order the points-replacement that goes with that distributor.

--DD