1970 Coupe 472 Vacuum Lines - Page 2
Cadillac
 

Cadillac Forums | Help Us Help You | Advertise | Cadillac Parts | Cadillac News | Cadillac Classifieds / (Old System)

Cadillac Technical Archive | Cadillac Dealers | Cadillac Reviews | Cadillac Dealer Reviews | Cadillac Vendors

CadillacForums.com is the premier Cadillac Forum on the internet. Registered Users do not see the above ads.
+ Reply to Thread
Page 2 of 3 FirstFirst 1 2 3 LastLast
Results 16 to 30 of 31
Like Tree8Likes
500, 472, 425, 368 Discussion, 1970 Coupe 472 Vacuum Lines in Cadillac Engine Technical Discussion; In your opinion, does the rubber grommet really matter for the hole in the bottom of the distributor that the ...
  1. #16
    Cristofo's Avatar
    Cristofo is offline Cadillac Owners Fanatic
    Automobile(s): 1990 Cadillac Sedan De Ville, 1970 Cadillac Coupe De Ville
    Join Date
    Apr 2009
    Location
    Philadelphia
    Age
    31
    Posts
    244

    Re: 1970 Coupe 472 Vacuum Lines

    In your opinion, does the rubber grommet really matter for the hole in the bottom of the distributor that the wires run through? I cannot get any leverage to pop the rubber grommet back in, but i'm hesitant to leave it like that. I'm guessing its more to keep debris/moisture out of the distributor? If so than I'll make sure to get it in there snug. I know alot of people use the Petronix system but I have a soft spot for Accel products for some reason. I've had good results with every Accel product I've bought since my first car at 16 (Olds Cutlass Supreme 307 V8). Knock on wood, because of course I would say that right in mid-install of another yellow auto part haha.

    Last question and this is a dumb one that I never could figure out. If I was bypassing the thermal 3 port switch thing, which connection should be made directly to the vacuum advance? The manifold vacuum or ported? And where is the ported vacuum located, front right of the carb?

  2. #17
    chrisntam is offline Cadillac Owners Fanatic
    Automobile(s): 1970 Deville Convertible
    Join Date
    Oct 2012
    Location
    North Texas
    Posts
    134

    Re: 1970 Coupe 472 Vacuum Lines

    yeah, I had my share of accel stuff too. Super coil, dual point distributors, wires, etc. Pretty good stuff. As far as the grommet goes, I would try to get it back in, it seals out the bad stuff and insulates the wire going into the distributor. Get it started??

  3. #18
    Cristofo's Avatar
    Cristofo is offline Cadillac Owners Fanatic
    Automobile(s): 1990 Cadillac Sedan De Ville, 1970 Cadillac Coupe De Ville
    Join Date
    Apr 2009
    Location
    Philadelphia
    Age
    31
    Posts
    244

    Re: 1970 Coupe 472 Vacuum Lines

    Quote Originally Posted by chrisntam View Post
    yeah, I had my share of accel stuff too. Super coil, dual point distributors, wires, etc. Pretty good stuff. As far as the grommet goes, I would try to get it back in, it seals out the bad stuff and insulates the wire going into the distributor. Get it started??
    Not yet, I won't be back to the car until tomorrow again around lunchtime.

  4. #19
    Cristofo's Avatar
    Cristofo is offline Cadillac Owners Fanatic
    Automobile(s): 1990 Cadillac Sedan De Ville, 1970 Cadillac Coupe De Ville
    Join Date
    Apr 2009
    Location
    Philadelphia
    Age
    31
    Posts
    244

    Re: 1970 Coupe 472 Vacuum Lines

    Update:

    Got everything wired correctly, i routed ground wire to one of the bolts holding the ignition coil on along with + and - on ignition coil terminals. Car fired up and was idling pretty smooth and idle speed seemed lower. Took it out and it was driving really well on about 5 degrees timing but was kinda lazy. I upped it to about 10 degrees and it drove really well and strong but as I was driving all engine power cutout. I'm basically on the E line and not sure how much gas is left so Im hoping it just needs gas. It still fires up but is idling so low and lumpy there is virtually 0 engine power and car seems to want to stall out but stays on. I had to push the car into a spot at the place we keep it Does this sound like im out of fuel or almost out? Could something have broken while i was mid acceleration? I have yet to remove the distributor cap but will investigate after i put some gas in the tank.

    http://i899.photobucket.com/albums/a...m/P3091075.jpg
    I have a broken nipple where your red tape is as well.

    Chris

  5. #20
    chrisntam is offline Cadillac Owners Fanatic
    Automobile(s): 1970 Deville Convertible
    Join Date
    Oct 2012
    Location
    North Texas
    Posts
    134

    Re: 1970 Coupe 472 Vacuum Lines

    I'd put gas in it to rule that out first. I think though once it runs out, it's out. I'd then go back and recheck all your work, check the connections and make sure the distributor didn't slip. Is it making any new noises? If no, nothing prolly broke, lets hope so! My guess is something is loose or slipped or your low/out of gas. I'm good at hanging parts, not so good at diagnosis..........

  6. #21
    Cristofo's Avatar
    Cristofo is offline Cadillac Owners Fanatic
    Automobile(s): 1990 Cadillac Sedan De Ville, 1970 Cadillac Coupe De Ville
    Join Date
    Apr 2009
    Location
    Philadelphia
    Age
    31
    Posts
    244

    Re: 1970 Coupe 472 Vacuum Lines

    I removed the accel kit and installed a pertronix and superstock accel coil. I think the accel eliminator bit the dust after I had running. My timing is set at 8 but idle seems low. I didn't get a chance to drive it but its all buttoned up. Time to finish the vacuum lines and adjust idle air screws.

  7. #22
    chrisntam is offline Cadillac Owners Fanatic
    Automobile(s): 1970 Deville Convertible
    Join Date
    Oct 2012
    Location
    North Texas
    Posts
    134

    Re: 1970 Coupe 472 Vacuum Lines

    Good to hear!!

  8. #23
    Cristofo's Avatar
    Cristofo is offline Cadillac Owners Fanatic
    Automobile(s): 1990 Cadillac Sedan De Ville, 1970 Cadillac Coupe De Ville
    Join Date
    Apr 2009
    Location
    Philadelphia
    Age
    31
    Posts
    244

    Re: 1970 Coupe 472 Vacuum Lines

    few things...

    Petronix
    I measured the voltage at at the coil and I'm only seeing like 5 volts, instead of the 12 like it needs...Weird though that its running ok. I will need to run a wire or find a wire that has 12V and tap into it, any suggestions?

    Cooling System
    My heater core or something inside the box is leaking coolant and coming out the bottom of the heater core housing unit. Found myself another project! Ugh, kind of frustrating but nature of the beast I guess.

    Vacuum Hoses
    http://i899.photobucket.com/albums/a...m/P3091075.jpg
    The vacuum check valve on the firewall that has 4/5 connections had the leftside nipple just open with nothing attached. I'm thinking this is where the hose connecting to the underside of the air cleaner housing routes to in stock form. Currently I have the check valve nipple capped along with the air cleaner hose. Any idea where I can get a replacement vacuum check valve? My leftside nipple is broke so its hard to cap it or connect a hose in its current form.

    Distributor Advance
    I hooked up a hose directly from the front right side of the carb to the vacuum advance. I noticed at idle, with the advance connected my timing doesn't move from where I set it (Currently @ 6 degrees). Does this mean the advance is busted and need a new one? I just got a replacement distributor with one attached last year.

  9. #24
    chrisntam is offline Cadillac Owners Fanatic
    Automobile(s): 1970 Deville Convertible
    Join Date
    Oct 2012
    Location
    North Texas
    Posts
    134

    Re: 1970 Coupe 472 Vacuum Lines

    Quote Originally Posted by Cristofo View Post
    few things...

    Petronix
    I measured the voltage at at the coil and I'm only seeing like 5 volts, instead of the 12 like it needs...Weird though that its running ok. I will need to run a wire or find a wire that has 12V and tap into it, any suggestions?

    Do you have a factory service manual? The wiring diagram shows what I recall to be a 12 gauge pink wire coming off the ignition switch. I made sure that wire tied into the resistor wire and once that was confirmed, I cut the pink wire, put a solderless connector on it, ran a new wire thru the firewall to the solderless connector, put another on and connected the two. Ran the new wire to the + side of the coil. I also cut the resistor wire where it tied to the other one at the + side of the coil. That other wire comes from the starter and allows voltage to flow to the coil while the key is in the crank position. Put another solderless connector on the new wire, put both wires on the + side of the coil. I left the resistor wire in place, but "abandoned" should I or anyone want to re-install the old distributor. With all that, you'll have 12 volts to the + side of the coil.

    Cooling System
    My heater core or something inside the box is leaking coolant and coming out the bottom of the heater core housing unit. Found myself another project! Ugh, kind of frustrating but nature of the beast I guess.

    When I had mine all apart, I tried to replace the heater core. Bought the most expensive one (and I assumed the best one) from RockAuto, but the tubes were bent slightly different and it didn't fit exactly. I ended up returning it and putting the old one back in. The suggested to bend it to fit, but the warranty that came with it said if you return a defective unit and it leaks at the tubes, no warranty honored. I said BS on that and sent it back. There's no real way to bend it and not chance breaking it. A local parts store should have one or be able to get one for you. I do "highly" recommend you get a factory service manual if you don't have one. Piles and piles of great information. They come up on eBay and anything under $25 for one is a good price. Lots on there for $30 to $50, that's too much. The FSM will tell exactly how to do the heater core. It is kind of a pita, but I did it so it can't be too hard. Just has some screws that are hard to get to.

    Vacuum Hoses
    http://i899.photobucket.com/albums/a...m/P3091075.jpg
    The vacuum check valve on the firewall that has 4/5 connections had the leftside nipple just open with nothing attached. I'm thinking this is where the hose connecting to the underside of the air cleaner housing routes to in stock form. Currently I have the check valve nipple capped along with the air cleaner hose. Any idea where I can get a replacement vacuum check valve? My leftside nipple is broke so its hard to cap it or connect a hose in its current form.

    I put duct tape over mine and it appears to be doing ok. It's a junk yard item only. Find someone parting a car out and get one there. Don't know if they were on other years or not, maybe on a '69, not sure.

    Distributor Advance
    I hooked up a hose directly from the front right side of the carb to the vacuum advance. I noticed at idle, with the advance connected my timing doesn't move from where I set it (Currently @ 6 degrees). Does this mean the advance is busted and need a new one? I just got a replacement distributor with one attached last year.
    I'm having what I think are timing issues too, so not sure if I can truly help on this. My thinking is the carb port where the hose is connected is "ported" vacuum, meaning it won't pull vacuum until maybe 1000 or 1500 RPM and shouldn't pull much, if any at idle. I checked the port I have mine connected to and at idle, it had about 5" of vacuum. Revving up the motor showed it was pulling 15" or so, which is what I believe is correct, though not 100% sure, as I'm using a carb from a '76. Check the port with a vacuum gauge to be sure. Along with the vacuum advance, you have the centrifugal advance too. When the timing light is connected, and you rev the motor, does the timing advance?

    My newly rebuilt motor is not running right like I think it should and I'm about to take to a local speed shop to have them tune it to see if they can make it run any better. A parts replacer I am, a diagnostician, I am not, but I try.

  10. #25
    Cristofo's Avatar
    Cristofo is offline Cadillac Owners Fanatic
    Automobile(s): 1990 Cadillac Sedan De Ville, 1970 Cadillac Coupe De Ville
    Join Date
    Apr 2009
    Location
    Philadelphia
    Age
    31
    Posts
    244

    Re: 1970 Coupe 472 Vacuum Lines

    I need to go back and find the pink ignition switch wire and run it straight to the coil, and I'll be bypassing the heater core for the time being. That should take care of most of my issues, then I will be hooking up full manifold vacuum to my distributor advance. I'm currently hooked up to ported vacuum like you said. Once I get this all taken care of, I just need to mess with the idle screws and I think I'll be all set.

    Back to the vacuum check valve on the firewall with 5 total vacuum connections...Can I replace that valve with just vacuum T's or does that withold vacuum from the bottom port?

  11. #26
    chrisntam is offline Cadillac Owners Fanatic
    Automobile(s): 1970 Deville Convertible
    Join Date
    Oct 2012
    Location
    North Texas
    Posts
    134

    Re: 1970 Coupe 472 Vacuum Lines

    I think the vacuum advance should be connected to ported vacuum, not full manifold vacuum. The logic is that at idle, the advance would be under vacuum and thus the timing would be advanced (at idle). I don't "think" that's what you want, let others chime in. I understand the advance is needed as the motor revs. Where are the others who know??? 900+ views and no one else has anything to add????

    Not sure what the purpose of the check valve is or what ports are "checked".

    Maybe start a new thread with those specific questions. Maybe this one is too long to scroll down and answer. Don't know.

    The folks here: http://forums.cadillaclasalleclub.org/index.php are Cadillac purists, and they have tons of knowledge, I get a lot of answers there, you may try posting there too.

  12. #27
    Cristofo's Avatar
    Cristofo is offline Cadillac Owners Fanatic
    Automobile(s): 1990 Cadillac Sedan De Ville, 1970 Cadillac Coupe De Ville
    Join Date
    Apr 2009
    Location
    Philadelphia
    Age
    31
    Posts
    244

    Re: 1970 Coupe 472 Vacuum Lines

    I'm not sure, I'm guessing since this is such a frequent issue everyone is over it. Thanks for your help, you definitely enlightened me. I will leave the ported vacuum hooked up for now and it makes sense to not have advance at idle which explains why the timing stays still. I will rev the engine and check timing to see if it advances.

    The port you have taped up on your vacuum valve is the same port on mine that is broke. Its hard to keep a vacuum hose/cap on there without tape. I'm sure there is a slight leak there still but its way better than before (you could hear that leak from 20 ft away).

    I'm going to bypass the heater core by just putting a connection at the inlet/outlet hoses, i won't need heat anyway so might as well remove it.

  13. #28
    Submariner409's Avatar
    Submariner409 is offline If it won't run, stick on fender vents
    Automobile(s): 2002.5 F55 STS/65500mi, 2004 Ford F150 SuperCab4x4
    Join Date
    Feb 2006
    Location
    MD Eastern Shore - Kent Island
    Age
    74
    Posts
    44,579

    Re: 1970 Coupe 472 Vacuum Lines

    Some engines use ported vacuum advance, some don't. Vacuum is used to advance timing for light loads - as load increases, the throttle butterflies open more, manifold vacuum drops, and timing slowly retards depending on manifold vacuum. Engines NEVER use maximum advance under heavy load - it's always some value less than maximum mechanical + vacuum.

    Most of these ignition systems start on 12 volts, then when the key is released to RUN the ballast resistor or resistance wire runs the coil on 5 or 6 volts.

    Double check your wiring and vacuum setup for that car - All my Olds 455 marine engines run Pertronix Ignitors and coils, and they start on 12 volts and run on 6. I run modified AC Delco distributors with adjustable Crane vaccum cans - and they use full vacuum at idle.

    Right underneath the coil - look hard - two wires, white and red (my wiring) go to the ballast resistor. It's bypassed for cranking.
    Attached Images
    Cristofo and chrisntam like this.

  14. #29
    chrisntam is offline Cadillac Owners Fanatic
    Automobile(s): 1970 Deville Convertible
    Join Date
    Oct 2012
    Location
    North Texas
    Posts
    134

    Re: 1970 Coupe 472 Vacuum Lines

    YEAH!! I knew others would chime in!!

  15. #30
    Cristofo's Avatar
    Cristofo is offline Cadillac Owners Fanatic
    Automobile(s): 1990 Cadillac Sedan De Ville, 1970 Cadillac Coupe De Ville
    Join Date
    Apr 2009
    Location
    Philadelphia
    Age
    31
    Posts
    244

    Re: 1970 Coupe 472 Vacuum Lines

    i'll be with the car later this week or weekend and will button a few things up while I'm bypassing the heater core. I have the Petronix Ignitor #1181 and I removed the cylinder shaped resistor on the coil but still have the resistor wire attached im assuming. I will move it so it bypasses the resistor and recheck voltage. The ignitor seems to run fine with around 5 volts, so not sure it matters? Is it strange that its running ok with 12 volts at crank and 5 volts at idle?

Quick Reply Quick Reply

Register Now

Please enter the name by which you would like to log-in and be known on this site.
If you do not want to register, fill this field only and the name will be used as user name for your post.

Please enter a password for your user account. Note that passwords are case-sensitive.

Please enter a valid email address for yourself.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Bookmarks

Cadillac Posting Rules

  • You may post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
Read about Lincoln | Buick | Kia Forte Forum
Need products for your Cadillac? Check out your options at the links below:

custom floor mats | Cadillac Chrome and Black Chrome Wheels | window tinting