Weissach

Vacuum advance for an 83' Euro (CIS). Does anyone know how to check it? I had the car parked for a while(a few months), but it now feels very flat. The car is very smooth and it's not missing. The car has no cat, so it can't be the exhaust. Any ideas???

GlenL

You can take the distributor to an old-school performance shop where they'll have test equipment for it. Internally, it's just another spark and mechanical advance unit.

A first check is to pull off the vacuum lines while it's running. The top line is advance. The one attached underneath is retard. If it idles fine then it's likely not the distributor.

Sitting a few months? Run the gas down really low and then go with a bottle of Techron added to the right amount of gas.

Garth S

If you have a 'mityvac', remove the dist. cap, and draw a vacuum on the advance line ( and retard - if it's still on the '83). You will see the plate move if the diaphrams are good and the mechanism is free. Otherwise, pucker up, and suck on the tube to achieve the same result (WSM Tech Bulletin 42-673 ). Then, reassemble and start the engine - checking for vacuum on the line(s) ....

jpitman2

If the advance/retard unit on the dist is OK, I would suspect the vacuum lines, unless you have done them? I replaced all of mine a while ago. I actually pulled some of the inlet spider legs to make access to rear of throttle body easy - not too difficult really, makes everything clear. Only do one hose at a time, so you dont get lost.
jp 83 Euro S AT 48k