Welcome! Please use the navigational links to explore our website.
PartsASAP LogoCompany Logo Auction Link (800) 853-2651

Shop Now

   Allis Chalmers Case Farmall IH Ford 8N,9N,2N Ford
   Ferguson John Deere Massey Ferguson Minn. Moline Oliver

Ford 9N, 2N & 8N Discussion Forum
:

Carburator vacuum

Welcome Guest, Log in or Register
Author 
Paul (MA)

01-03-2004 13:32:23




Report to Moderator

If I remove the plug in the intake/exhaust manifold on my 52 8N should there be a constant vacuum? When I remove mine I get vacuum with regular intervals of possitive pressure. Would this be caused by a burned out manifold or gasket, or is this normal?




[Log in to Reply]   [No Email]
Dell (WA)

01-04-2004 13:17:03




Report to Moderator
 Re: Carburator vacuum in reply to Paul (MA), 01-03-2004 13:32:23  
Paul..... ...most 4-cylinder engines have a natural vacuum pulse. Try "dampning" the pulses by squeezing the rubber hose almost closed like you'd do a lawn water hose..... ....Dell



[Log in to Reply]  [No Email]
Clint

01-04-2004 15:38:28




Report to Moderator
 Re: Re: Carburator vacuum in reply to Dell (WA), 01-04-2004 13:17:03  
Now waitaminit, Dell. Sure there are gonna be pulses, especially when the motor is thottled back to idle. That's becuz you only have 4 cyls pulling an intake stroke every other revolution. (4/2=2) So, at say 600 Rpm, you would have 1200 pulses per minute. But the throttle plate is closed, restricting airflow into the manifold, so vacum should decline relatively slowly as the air leaks past the throttle plate. And, it should never go positive, even if the duration between intake pulses is a millenium. The only way manifold pressure can go higher than zero is if an intake valve is pumping pressure back into the intake. I'd go with the sticking valve theory, although he didn't help himself out any by not telling us what problem he was trying to diagnose.

[Log in to Reply]  [No Email]
raytasch

01-03-2004 15:17:45




Report to Moderator
 Re: Carburator vacuum in reply to Paul (MA), 01-03-2004 13:32:23  
There should be constant vacuum of somewhere just less than 20 inches; 18-20 inches. If you are getting a wide rythmetic swing between vacuum and pressure I would suspect an intake valve sticking or spring broken. I have seen broken valve springs allow a good compression test yet cause a miss due to the valve failure to close.
ray



[Log in to Reply]  [No Email]
Paul (MA)

01-03-2004 13:36:37




Report to Moderator
 Re: Carburator vacuum in reply to Paul (MA), 01-03-2004 13:32:23  
Sorry forgot to mention compression is good on all 4 cyl. (about 100) so I am figuring it is not a valve issue.



[Log in to Reply]  [No Email]
[Options]  [Printer Friendly]  [Posting Help]  [Return to Forum]   [Log in to Reply]

Hop to:


TRACTOR PARTS TRACTOR MANUALS
We sell tractor parts!  We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]

Home  |  Forums


Copyright © 1997-2023 Yesterday's Tractor Co.

All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy

TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.

Yesterday's Tractors - Antique Tractor Headquarters

Website Accessibility Policy