Welcome to Club Hot Rod!  The premier site for everything to do with Hot Rod, Customs, Low Riders, Rat Rods, and more. 

  •  » Members from all over the US and the world!
  •  » Help from all over the world for your questions
  •  » Build logs for you and all members
  •  » Blogs
  •  » Image Gallery
  •  » Many thousands of members and hundreds of thousands of posts! 

YES! I want to register an account for free right now!  p.s.: For registered members this ad will NOT show

 
Like Tree39Likes

Thread: Low engine vacuum but no vacuum leaks.
          
   
   

Reply To Thread
Page 3 of 4 FirstFirst 1 2 3 4 LastLast
Results 31 to 45 of 49
  1. #31
    34_40's Avatar
    34_40 is offline CHR Member Visit my Photo Gallery
    Join Date
    Sep 2007
    Location
    New Bedford
    Car Year, Make, Model: 34 Ford 3W Coupe Replica
    Posts
    12,734

    Quote Originally Posted by 36 sedan View Post
    Aaaaaaaah?????? low vacuum!!, I don't want to come off as the bad guy again, so I'll butt the h-ll out........
    No Sinsei, young grasshopper needs all the help he can get. And you have the way of addressing a member with respect. Some of us lose patience and can become gruff.

    Perhaps now is the time for the air pump example? So a Low vacuum signal can mean air cannot get out so it won't get air in. Equals low power!
    36 sedan likes this.

  2. #32
    47Fordcoupe's Avatar
    47Fordcoupe is offline CHR Member Visit my Photo Gallery
    Join Date
    Jul 2018
    Location
    smithfield
    Car Year, Make, Model: 1947 Ford Coupe
    Posts
    23

    I appreciate everyone's input on this issue. Just a disclaimer, I by no means whatsoever consider myself to be an expert mechanic, as I'm sure many of you are.. i have very basic engine knowledge which is why I came here for help. However, I've seen replies on here suggesting I do things I have already done. Just in case some of you have missed what I've already done, I'm going to post it here once more. Things that I've done trying to solve the problem prior to my post:

    1-Checked idle timing multiple times. (It's showing 30* and I know I should be around 4-12* at idle)
    2- established tdc using a piston stop 3 times to confirm, yes marked the center of the 2 points)
    3- verified that the harmonic balancer did not slip from the inner ring by marking between the 2 rings.
    4- checked for vacuum leaks using propane gas, as well as with a smoke machine. No leaks found.
    5- replaced spark plugs, wires, HEI distributor rotor and cap. (Installed the new spark plugs wires in the same order they were in, which COULD be problem)
    6- adjusted the Edelbrock 500 cfm carburetor by turning the idle mixture screws all the way in (clockwise) and then 1 1/2 turn counterclockwise (I know that's a starting base)
    7- removed valve covers and verified that no valves were sticking with the engine idling.

    Thanks again to all who have tried to help and please keep the suggestions coming ��
    Last edited by 47Fordcoupe; 07-29-2018 at 01:49 PM.

  3. #33
    techinspector1's Avatar
    techinspector1 is offline CHR Member Visit my Photo Gallery
    Join Date
    May 2003
    Location
    Zephyrhills, Florida, USA
    Car Year, Make, Model: '32 Henway
    Posts
    12,281

    On page 1, post 13, I outlined two procedures to help you determine the problem(s). Apparently you ignored them, because I have not seen any results. All of us are grabbing at straws trying to help you, but if you're not going to follow our suggestions, then you're probably not going to find the problem and that's OK because I'll still sleep well tonight regardless. I didn't start this post to be snotty, but damnit, I'm not getting any input and I'm beginning to think I'm wasting my time trying to help. Now get your sheets together or I'm outa here and I suspect the rest of the gang will be too.
    Last edited by techinspector1; 07-29-2018 at 02:43 PM.
    NTFDAY and 36 sedan like this.
    PLANET EARTH, INSANE ASYLUM FOR THE UNIVERSE.

  4. #34
    NTFDAY's Avatar
    NTFDAY is offline CHR Member Visit my Photo Gallery
    Join Date
    Aug 2003
    Location
    Springfield
    Car Year, Make, Model: '66 Mustang, 76 Corvette
    Posts
    4,586

    Turn out the lights, the partys over............................
    36 sedan likes this.
    Ken Thomas
    NoT FaDe AwaY and the music didn't die
    The simplest road is usually the last one sought
    Wild Willie & AA/FA's The greatest show in drag racing

  5. #35
    47Fordcoupe's Avatar
    47Fordcoupe is offline CHR Member Visit my Photo Gallery
    Join Date
    Jul 2018
    Location
    smithfield
    Car Year, Make, Model: 1947 Ford Coupe
    Posts
    23

    Quote Originally Posted by techinspector1 View Post
    On page 1, post 13, I outlined two procedures to help you determine the problem(s). Apparently you ignored them, because I have not seen any results. All of us are grabbing at straws trying to help you, but if you're not going to follow our suggestions, then you're probably not going to find the problem and that's OK because I'll still sleep well tonight regardless. I didn't start this post to be snotty, but damnit, I'm not getting any input and I'm beginning to think I'm wasting my time trying to help. Now get your sheets together or I'm outa here and I suspect the rest of the gang will be too.
    I have seen all the suggestions given here, and I said I appreciate it. I'm just hoping to gather more suggestions as I am currently out of town therefore haven't been able to work on the car till I arrive next weekend.

  6. #36
    36 sedan's Avatar
    36 sedan is offline CHR Member Visit my Photo Gallery
    Join Date
    Apr 2012
    Location
    american canyon
    Car Year, Make, Model: 36 Ford Sedan, 23 T Bucket
    Posts
    1,335

    Quote Originally Posted by techinspector1 View Post
    Now get your sheets together or I'm outa here and I suspect the rest of the gang will be too.
    Quote Originally Posted by NTFDAY View Post
    Turn out the lights, the partys over............................
    /\ /\ What they say!!!

  7. #37
    shine's Avatar
    shine is offline CHR Member Visit my Photo Gallery
    Join Date
    Nov 2003
    Location
    bluff dale texas
    Car Year, Make, Model: 47 inderweed
    Posts
    1,793

    if it's anything like some of my ordeals you'll end up setting on a chair by it wondering how you remembered to breath. i have spent weeks chasing some of the simplest things . good luck with it .

  8. #38
    47Fordcoupe's Avatar
    47Fordcoupe is offline CHR Member Visit my Photo Gallery
    Join Date
    Jul 2018
    Location
    smithfield
    Car Year, Make, Model: 1947 Ford Coupe
    Posts
    23

    Quote Originally Posted by 34_40 View Post
    In addition to what every one else has offered.
    Don't hesitate to open the exhaust at the manifolds and re-do a vacuum test. It's not seen much anymore but exhaust pipe sometimes had a interior pipe that would swell and kink closing off the pipe. This would effectively choke the motor airflow/vacuum. Like I said, you don't see this anymore but it should be easy (relatively speaking) to open the headers/manifolds and double check the vacuum.
    Could you please specify what you mean by opening the exhaust at the manifold ? Do you mean to remove the exhaust manifold to check for obstruction? Thanks

  9. #39
    firebird77clone's Avatar
    firebird77clone is offline CHR Member Visit my Photo Gallery
    Join Date
    Sep 2005
    Location
    Hamilton
    Car Year, Make, Model: 69 nomad, 73 charger, 74 vega
    Posts
    3,286

    He means disconnect the exhaust pipe where it connects to the manifold. This would remove any back pressure generated by the exhaust.
    34_40 and 47Fordcoupe like this.
    .
    Education is expensive. Keep that in mind, and you'll never be terribly upset when a project goes awry.
    EG

  10. #40
    34_40's Avatar
    34_40 is offline CHR Member Visit my Photo Gallery
    Join Date
    Sep 2007
    Location
    New Bedford
    Car Year, Make, Model: 34 Ford 3W Coupe Replica
    Posts
    12,734

    Yes, open the connector/ connection at the manifold and re-do your vacuum readings, see if it improves
    47Fordcoupe likes this.

  11. #41
    Driver50x's Avatar
    Driver50x is offline CHR Member Visit my Photo Gallery
    Join Date
    Jul 2016
    Location
    Saint Petersburg, Florida
    Posts
    211

    The problem could be a loose timing chain. That was very common on those small block Chevys, when the nylon falls off of the camshaft sprocket.
    Dave Severson likes this.
    Steve

  12. #42
    DennyW is offline CHR Member Visit my Photo Gallery
    Join Date
    Oct 2004
    Location
    city
    Car Year, Make, Model: 34 chevy truck
    Posts
    943

    Quote Originally Posted by Driver50x View Post
    The problem could be a loose timing chain. That was very common on those small block Chevys, when the nylon falls off of the camshaft sprocket.
    Yes, I mentioned that in my post. #6. No replies though...He is out of town I guess.

  13. #43
    Driver50x's Avatar
    Driver50x is offline CHR Member Visit my Photo Gallery
    Join Date
    Jul 2016
    Location
    Saint Petersburg, Florida
    Posts
    211

    Quote Originally Posted by DennyW View Post
    Yes, I mentioned that in my post. #6. No replies though...He is out of town I guess.
    Whoops, I read through it and missed that.
    Steve

  14. #44
    47Fordcoupe's Avatar
    47Fordcoupe is offline CHR Member Visit my Photo Gallery
    Join Date
    Jul 2018
    Location
    smithfield
    Car Year, Make, Model: 1947 Ford Coupe
    Posts
    23

    Sorry for the late update,lost my user name and password and just got it back.
    I'm still having the low vacuum issue. But I believe the issue is due to a rad cam. The person who I bought the car from said he thought the car had a big cam but he was the 2nd owner of the car so he was't really sure. But at least I was able to figure out why the car was running like crap...and it was due to a bad HEI ignition module. I replaced the module and the car is running much better, but still at about 10'' of vacuum at idle.

  15. #45
    selmorides's Avatar
    selmorides is offline CHR Member Visit my Photo Gallery
    Join Date
    Feb 2003
    Location
    La Salle
    Car Year, Make, Model: 65 Pontiac Tempest Custom 2 door hardtop
    Posts
    32

    I see this is an old post but I am dealing with that now on a new cam install. Valves hanging open is what the internet say. I'm going thru the valves again using a different method. I'll let you know how it goes.

Reply To Thread
Page 3 of 4 FirstFirst 1 2 3 4 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
Links monetized by VigLink