vacume advance

eric_ciampa · 02-12-2003, 02:47 PM

My 914 came with a larger vacume advance. it has what looks like two nipples for vacume hoses with the one facing the distributer closed off and the one facing away from the distrubuter going to the throttle body. Is this the right vacume advance? should one be blocked off like that? and where can i get a new/rerbuilt one... i dont see one on PP. i might just be ignorant though

coconut 321 · coconut 321's Garage

Eric; I also have a '74 1.8l stock engine. My vacuum advance is just the opposite of yours ie: the nipple facing the dist. has a vacuum hose to the throttle body, while the nipple facing away from the dist. is open. It works for me!

eric_ciampa · 02-12-2003, 05:34 PM

the nipple on mine is not open to the air... it has a cap on it which does not seem right. Also the one i have is bad, meaning it does not hold a vacum when tested so i will need a new one

.... ok and i just checked and on mine the nipple on the distributer side is the one that is capped of while the one on the other side went to the previous side. so i need a new V. Advance any ideas?

yoh!!! · yoh!!!'s Garage

Hmmm, IIRC the side of the vacuum can that faces the dizzy is the vacuum retard side. The other side is the vacuum advance side.
Blocking one side seems not to be a good idea. Check on the Tech pages for a diagram that shows how the hoses should be hooked up – I think I have seen something for a 1.8l

Patrick

Dave at Pelican Parts · Dave at Pelican Parts's Garage

The fittings on the distributor get hooked to the fittings on the throttle body. If there is only one fitting on the throttle body, it goes to the retard (pointing at the distributor body) fitting on the distributor.

They used the same distributor dashpot for the 74+ cars that didn't have vacuum advance (cheaper that way), they just didn't drill the throttle body for the advance fitting.

If you do not have vacuum advance, you should leave that fitting on the distributor open to air. Or do what the factory (or dealer?) did--put a hose on it and run it somewhere out of sight so it doesn't look odd. I have been told that capping the advance fitting messes up the operation of the vacuum retard.

--DD

pbanders · pbanders's Garage

Quote:

Originally posted by Dave at Pelican Parts
...vacuum advance, you should leave that fitting on the distributor open to air. Or do what the factory (or dealer?) did--put a hose on it and run it somewhere out of sight so it doesn't look odd. I have been told that capping the advance fitting messes up the operation of the vacuum retard.

--DD

It's possible that capping could cause a problem, though I can't immediately see how. Even a tightly capped line would be at atmospheric pressure. If the adv cell's diaphragm moved due to action of the retard cell, then it's possible it might "resist" the action of the retard cell, as the action of the advance cell is dominant over the retard cell.

I've got a spare dizzy, I'll play with it and see what the effects are.

eric_ciampa · 02-13-2003, 09:10 AM

~ DD
Does Pelican Parts sell these? I cant find them in your catalog anywhere. Mine is bad and cannot hold a vacume. If you guys dont carry them who would... thanks

Dave at Pelican Parts · Dave at Pelican Parts's Garage

Just because it isn't in the catalog....

Call up and ask. Steve is definitely a 914 guy, he should be able to find the bits in the internal lists.

--DD