Jump to content

z22 vacuum advance


mr 202

Recommended Posts

Hello i was wondering if anyone on here has the answer im lookin for, i have a 620 that i previously owned and got back but i got it back with a z22 in it and it has a weber 32/36 and im putting a pacesetter header on it this weekend, and it runs great and has good power but it doesnt have the vacuum advance hooked up that is on the distributor, and was wondering wether or not it helps or hurts the motor/ power,

 

 

any input would help at this point because i cant find anything about it

 

 

Thanks

Link to comment
  • Replies 7
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

well if its capped off at the carb its fine i guess, but im sure you would gain a little by having it hooked up.

 

 

ok so if i wanted to hook it up to see if it changes anything, would i hook up a vacuum line, and it looks like a wire of some sort needs to be hooked up to the male connector that is off the side of the unit it looks to me like it may just be a ground but im asking because i dont actually know. lol

Link to comment

ok so if i wanted to hook it up to see if it changes anything, would i hook up a vacuum line, and it looks like a wire of some sort needs to be hooked up to the male connector that is off the side of the unit it looks to me like it may just be a ground but im asking because i dont actually know. lol

 

That male connector could be a ground that plugs in at the base of the dizzy, should see a tab sticking out.

You should run the advance...from dizzy to Weber

Link to comment

Low speed (idle to 2500) and part throttle will have less than a full cylinder of gas and air in it when it is compressed. There will be more space between the molecules of fuel and air. When it is fired it takes a little longer to fully burn so the timing needs to be slightly advanced. The ported vacuum at the carb is perfect for this being higher at low throttle and progressively less and less as the throttle is opened toward full. Thus the vacuum is load dependent and will advance as needed depending on how full the cylinder is. Since most driving is done below 2,500-3,000 an adjustable advance keeps the motor producing maximum power at part throttle settings. The motor will run cooler and be more driveable.

 

P/Os are weird and who knows what goes through their heads, but for sure we have to fix it and make it run right.

 

Pull the hose off the distributor and remove the cap. Suck on the end of the hose and you should see the rotor turn clockwise slightly and hold until you release it. If it does this then the vacuum advance is working properly.

 

The P/O may have changed the timing to compensate not having the vacuum advance connected so expect to retard the timing slightly when you connect it.

Link to comment
  • 2 months later...

I also was wondering about the wire connector on the advance unit...as my Z24 had a wire plugged in to it although the other end of that same wire went to the driver side fender/ignition coil area, but was clipped into a connector. Said connector wasn't plugged into anything, nor had it been in a long long time judging by the amount of dirt caked on the end...my truck runs fine...I was thinking maybe a lead for a tach signal considering if the truck had an o.e. tach...which mine didn't...where would the signal come from...either the negative side of the intake coil or the exhaust coil?...or from maybe that lead on the distributor itself...I will test this theory tonight...

Link to comment

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.

Loading...
×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.