Jump to content

Vacuum advance not working, wrong carb outlet?


Guest Anonymous
 Share

Recommended Posts

Guest Anonymous

I checked the timing of my 2002 today, and it was OK: 22

degree advance at 1000 rpm, standard 1973 2 liter, conform

the Haynes manual. But the timing doesn't change when the

vacuum thingy is hooked up again. Also, idle doesn't drop

when disconnecting the vacuum. Both the advance

mechanism and the hose are OK, But it seems the hose is

connected too high on the (single throttle valve, stock) carb!

Shouldn't it be hooked up really low on the carb, almost

across the throttle valve?

Please advise, I'm stumped with this one.

Thanks,

Hugo

Link to comment
Share on other sites

Guest Anonymous

If it's a single line vacuum advance model, the idea is that you want greater advance under cruise/light throttle conditions, and less advance when you step on it. This type of vacuum is found at the manifold, below the throttle plate. You could probably connect it straight to a manifold port, as well as to a carb port. Put a hose on the port that you think is the right one, and with the engine running, put your thumb or your tongue across the open end (uhhh, what's a vacuum gauge?). When the car is idling, you should feel some vacuum, and when you blip the throttle, it should disappear. If you pick the revs up to a steady 3000 rpm or so, you should feel vacuum. If you can run this test as you drive down the road (the picture of someone driving a 2002 with a vacuum hose on his tongue is just too good to pass up), you should be able to tell how the port responds to throttle inputs.

Mike

Link to comment
Share on other sites

Guest Anonymous

pop distributor cap off so you can see the point plate, then disconnect hose from the manifold end and suck on it. You should feel resistance and see the point plate move. No resistance=ruptured diaphragm; no point plate movement=jammed or worn point plate. Of course it never hurts to check the hose itself for cracks; they don't last forever!

Cheers

Mike

Link to comment
Share on other sites

Guest Anonymous

My carb has a fitting way above the throttle valve and one

that seems blocked and has no tube sticking out just below

the throttle valve. Should I 'unblock' the lower one and

connect?

Thanks,

Hugo

Link to comment
Share on other sites

Guest Anonymous

vacuum sensor of the LPG installation that is still in there (to

be removed soon) I think the LPG guy used the port and just

reconnected the other hoses at will. It runs a lot better now,

except for the mixture, see new post!

Thanks,

Hugo

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

  • Upcoming Events

×
×
  • Create New...