Jump to content



Resistance on Vac. Advance


  • Please log in to reply
24 replies to this topic

#1 81zfan

81zfan

    Established Member

  • Members
  • PipPipPip
  • 803 posts
  • Gender:Male
  • Location:KY
  • Interests:Wrenching,Fishing,Bicycling, and collecting old school vinyl!!
  • Model:Conquest

Posted 16 January 2019 - 06:55 AM

I've read several post on here about testing the vac advance by using the suction method.
How much resistance should the diaphragm have? Should you hear the weights moved so easily in the distributor when using suction?





#2 kev

kev

    Moderator

  • Moderators
  • PipPipPip
  • 4,940 posts
  • Gender:Male
  • Location:PA
  • Model:Other

Posted 16 January 2019 - 07:08 AM

When applying vacuum via a vacuum pump to the vac advance, the arm should start pulling in fairly easily with minimal vacuum and it should hold.  If the arm doesn't pull in, the diaphragm is shot.  If it pulls in but doesn't hold when you stop pumping, then the diaphragm has a small hole or you don't have a good seal between your pump and the vac. advance.

#3 81zfan

81zfan

    Established Member

  • Members
  • PipPipPip
  • 803 posts
  • Gender:Male
  • Location:KY
  • Interests:Wrenching,Fishing,Bicycling, and collecting old school vinyl!!
  • Model:Conquest

Posted 16 January 2019 - 07:48 AM

I applied vacuum and could hear hear the weights "I'M Guessing" moving in  the distributor.  I was curious as to the resistance of the springs and how easy they would move with slight vacuum. They are moving very easily but I didn't leave Vacuum on it to see if it would bleed out. I'll try it this weekend when it get past 32 degrees outside.
Thanks for the response Kev, I'll post back with some results after leaving Vac on the line

#4 scott87star

scott87star

    Technically Challenged, Daily.

  • Vendors
  • PipPipPip
  • 4,971 posts
  • Gender:Male
  • Location:Mandan, NORTH DAKOTA
  • Interests:Freezing, thawing, thunderstorms and constant wind.
  • Model:Starion

Posted 16 January 2019 - 12:15 PM

The weights and springs are not part of the vacuum advance, that's the centrifugal advance which changes the timing with increasing rpm.  That being said they tend to be a bit loose with no rpm and may clink with movement of the dizzy.  What does move with the vacuum advance is the stator, a brass colored three post item visible under the rotor and centrifugal advance.  Applying suction will move the stator CCW and you will be able to see the posts move, applying pressure moves the stator CW which retards the advance under boost.  Both functions are equally important, suck and blow and it should move and hold both directions.
Now selling true plug and play megasquirt!  Absolutely the best value in stand alone ECU's out there.

I can upgrade your Fuel Injection Pro firmware

Performance Coatings!  Pistons, manifolds, bearings and more!

Now a graduate of EFI University!  www.efi101.com

ECU Vendor link:  http://www.starquest...howtopic=137426

#5 81zfan

81zfan

    Established Member

  • Members
  • PipPipPip
  • 803 posts
  • Gender:Male
  • Location:KY
  • Interests:Wrenching,Fishing,Bicycling, and collecting old school vinyl!!
  • Model:Conquest

Posted 16 January 2019 - 02:28 PM

I was just making a guess as to what that sound is when suction is applied to the Vac hose. I understand the springs are not part of the vacuum advance but I haven't taken the cap and rotor off yet as it's still bolted to the motor. I was concerned that something may not have enough tension on it since it took very little resistance to hear parts move in Distributor.
I will pull the cap and stuff off and do a check on the things you spoke of. I never knew that there was also pressure going into the Vac advance hose, I was under the impression that it only pulled Vacuum. I'm glad I was able to learn this today.
I know you only hook this Vac advance hose up to the first nipple on the throttle body, so does that Vacuum source pull vacuum until boost builds, then it switches to pushing vacuum?
I forgot to mention that I followed the guide on here about tearing the Dist. apart and re-greasing everything but it has been a few years since all that was done and the car has only sit since then. It may have 75 miles on it since rebuilding the motor and stuff.
I really appreciate the help Scott..

Edited by 81zfan, 16 January 2019 - 02:32 PM.


#6 81zfan

81zfan

    Established Member

  • Members
  • PipPipPip
  • 803 posts
  • Gender:Male
  • Location:KY
  • Interests:Wrenching,Fishing,Bicycling, and collecting old school vinyl!!
  • Model:Conquest

Posted 16 January 2019 - 05:32 PM

Ok, so I went ahead and pulled the cap and button off and applied suction pressure and it held at the wide open spot for 45 min and didn't bleed off any, but I tried to blow pressure into it and it barely moved forward just a fraction, barely even noticeable. How far CW should it move and how much pressure does it noramlly take to move it in that direction. CCW it moves freely with no effort hardly. I just dont want to blow a lot of air into it and bust the Vac advance if it is good.

#7 scott87star

scott87star

    Technically Challenged, Daily.

  • Vendors
  • PipPipPip
  • 4,971 posts
  • Gender:Male
  • Location:Mandan, NORTH DAKOTA
  • Interests:Freezing, thawing, thunderstorms and constant wind.
  • Model:Starion

Posted 16 January 2019 - 10:32 PM

So there may be an issue, if you have a non-turbo vacuum advance it will not boost retard,  Pictures would make this easier.
Now selling true plug and play megasquirt!  Absolutely the best value in stand alone ECU's out there.

I can upgrade your Fuel Injection Pro firmware

Performance Coatings!  Pistons, manifolds, bearings and more!

Now a graduate of EFI University!  www.efi101.com

ECU Vendor link:  http://www.starquest...howtopic=137426

#8 81zfan

81zfan

    Established Member

  • Members
  • PipPipPip
  • 803 posts
  • Gender:Male
  • Location:KY
  • Interests:Wrenching,Fishing,Bicycling, and collecting old school vinyl!!
  • Model:Conquest

Posted 16 January 2019 - 10:43 PM

I can get a picture tmr but Iím 100% certain itís the original advance that came on the car. I picked up the car 10 years ago from the owner who bought it new and let it sit for years due to a cracked head, so itís been a mess to say the least trying to get everything working properly again. Haha

#9 croquest87

croquest87

    Established Member

  • Members
  • PipPipPip
  • 1,372 posts
  • Gender:Male
  • Location:willoughby
  • Interests:all things mechanical
  • Model:Conquest

Posted 17 January 2019 - 01:34 PM

I bought one at Advance Auto Parts  new this summer  think it was around $35.00 works perfect

#10 81zfan

81zfan

    Established Member

  • Members
  • PipPipPip
  • 803 posts
  • Gender:Male
  • Location:KY
  • Interests:Wrenching,Fishing,Bicycling, and collecting old school vinyl!!
  • Model:Conquest

Posted 17 January 2019 - 02:36 PM

I read another post where someone said they had gotten one for around that same amount. They must have went up at Advance and Oreilly's since then because I went both places yesterday and the cheapest I could get one at either place was 57 and that was with my shop discount. I still want to be able to test this one and  figure out how it supposed to operate when it's working  properly.

#11 81zfan

81zfan

    Established Member

  • Members
  • PipPipPip
  • 803 posts
  • Gender:Male
  • Location:KY
  • Interests:Wrenching,Fishing,Bicycling, and collecting old school vinyl!!
  • Model:Conquest

Posted 17 January 2019 - 03:37 PM

To be sure it is not leaking off I went ahead and put suction to the hose before work this morning. I'm gonna let it sit till I get off to see if it has bled off any in the 10 hours that it's been connected.

#12 croquest87

croquest87

    Established Member

  • Members
  • PipPipPip
  • 1,372 posts
  • Gender:Male
  • Location:willoughby
  • Interests:all things mechanical
  • Model:Conquest

Posted 17 January 2019 - 04:08 PM

It's good to know how to test things I agree. For peace of mind new vacuum advance with fresh diaphragm is priceless. Who knows how old the other one is probably never been replaced.

#13 81zfan

81zfan

    Established Member

  • Members
  • PipPipPip
  • 803 posts
  • Gender:Male
  • Location:KY
  • Interests:Wrenching,Fishing,Bicycling, and collecting old school vinyl!!
  • Model:Conquest

Posted 17 January 2019 - 04:18 PM

I totally agree with you.  I bought the car unseen 10 years ago from the original owner with I think about 67K miles on the odometer to find out the head was cracked and it had already been sitting for 9 or 10 years. I think i've put 60 or 70 miles on it since redoing the motor and stuff. I'd say it's well overdue for a new one!
I'll check to see if any pressure has bled off and if so I'll just go ahead and try to get one ordered.
Has anyone used the Rock auto ones?

#14 mikec

mikec

    not around much any more

  • Moderators
  • PipPipPipPip
  • 6,314 posts
  • Gender:Male
  • Location:Cypress California
  • Interests:Finish line at the Pikes Peak "Race to the Clouds"
  • Model:Starion

Posted 18 January 2019 - 12:03 AM

You can create a fair bit of suction with your lungs... but very little pressure.  A healthy person might be able to create 2 psi of pressure blowing into a tube.  The StarQuest distributor advancer/retard unit has to deal with pressures up to 12 psi so 2psi is barely enough to budge it in the retard direction.  You need a source of air pressure - like an air compressor with a really good pressure regulator - to test the unit without damaging it.

You'd have the same luck trying to test the turbo wastegate actuator by blowing into it... nothing would happen other than your face turning red.

mike c.

#15 81zfan

81zfan

    Established Member

  • Members
  • PipPipPip
  • 803 posts
  • Gender:Male
  • Location:KY
  • Interests:Wrenching,Fishing,Bicycling, and collecting old school vinyl!!
  • Model:Conquest

Posted 18 January 2019 - 06:51 AM

I think I've come to the conclusion that it is indeed bleeding off after a period of time. I applied full suction and it did indeed bleed off yesterday, so I went ahead and did the same exact test again and hooked a new Vac hose to the Dist. I checked it this morning and it has fully bled off again. It has a slow leak somewhere in the diaphragm I guess. I will try to get one ordered today.
I will post back when I get the new one and get it installed

#16 81zfan

81zfan

    Established Member

  • Members
  • PipPipPip
  • 803 posts
  • Gender:Male
  • Location:KY
  • Interests:Wrenching,Fishing,Bicycling, and collecting old school vinyl!!
  • Model:Conquest

Posted 22 January 2019 - 07:33 PM

SO I went to put the new Vac advance in today and while getting the old one out I noticed that the reluctor  feels like it isn't moving quite as smooth as it should. With the advance out, I moved the  reluctor CCW and it stayed in that position. should it return back without any pressure pushing against it?
It just feels like it should move smoother than it does

Edited by 81zfan, 22 January 2019 - 08:19 PM.


#17 importwarrior

importwarrior

    6 Quests and Counting......

  • Moderators
  • PipPipPipPipPip
  • 18,214 posts
  • Gender:Male
  • Location:Manassas VA
  • Interests:Boost = 2KWIK4U
    Starquests
  • Model:Conquest

Posted 22 January 2019 - 08:26 PM

Probably needs a good cleaning and a lube job.

B-71 87 TSI ~ RIP

Black 87 Starion ~ Mess SOLD!!!

Proud New 89 slightly Rusted Fiji Owner !!!




#18 81zfan

81zfan

    Established Member

  • Members
  • PipPipPip
  • 803 posts
  • Gender:Male
  • Location:KY
  • Interests:Wrenching,Fishing,Bicycling, and collecting old school vinyl!!
  • Model:Conquest

Posted 22 January 2019 - 08:28 PM

I was thinking the same thing. I did it a few years ago and it's just sit since then. I searched earlier for the guide on doing it, but came up empty,. Has it been removed ?

#19 importwarrior

importwarrior

    6 Quests and Counting......

  • Moderators
  • PipPipPipPipPip
  • 18,214 posts
  • Gender:Male
  • Location:Manassas VA
  • Interests:Boost = 2KWIK4U
    Starquests
  • Model:Conquest

Posted 22 January 2019 - 08:39 PM

Yes itís gone. Might be another location but not sure

B-71 87 TSI ~ RIP

Black 87 Starion ~ Mess SOLD!!!

Proud New 89 slightly Rusted Fiji Owner !!!




#20 81zfan

81zfan

    Established Member

  • Members
  • PipPipPip
  • 803 posts
  • Gender:Male
  • Location:KY
  • Interests:Wrenching,Fishing,Bicycling, and collecting old school vinyl!!
  • Model:Conquest

Posted 23 January 2019 - 06:55 AM

I've not been able to find it if it is.




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users