Effect of vacuum leak - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep CJ Forum > Effect of vacuum leak

TeraFlex Now at Rockridge 4WD! BEST DEALS around!Alloy usa heavy duty ball joint kitsENGO QUADLUX 6" to 54" LED AMBER AND WHITE MULTI

Reply
Unread 06-04-2008, 08:51 PM   #1
PaulS
Registered User
1949 CJ3A 
 
Join Date: Jun 2008
Location: Edmonton, AB
Posts: 83
Effect of vacuum leak

The previous owner of my 1950 CJ3A installed a vacuum gauge. The problem is that the hose to it leaks--to the point where you can hear the leak when the engine is running. The leak is obviously very close to the gauge, and not in the engine compartment.

I'm just curious what the effect of that leak would be on the engine performance. Any comments?

Off the top of my head I don't know where the vacuum line is connected (if it matters), but I will certainly find out. As soon as my little boy is asleep, I'll probably head out to start pulling steering components (see other threads...) and I'll check that line while I'm out there. I'm not ready to start dealing with engine performance yet--brakes and steering come first--but I can't stop thinking about lots of different things that will need work over the next while...

Thanks,

-Paul

PaulS is offline   Reply With Quote Quick reply to this message
Unread 06-05-2008, 06:46 AM   #2
PaulS
Registered User
1949 CJ3A 
 
Join Date: Jun 2008
Location: Edmonton, AB
Posts: 83
Checked, and the vacuum line ports directly into the intake manifold--specifically, the flow passage to the #4 cylinder. What would be the effect of a vacuum leak there?

-Paul
PaulS is offline   Reply With Quote Quick reply to this message
Unread 06-05-2008, 09:31 AM   #3
Mike Romain
Registered User
1986 CJ7 
 
Join Date: Nov 2007
Location: Off the Grid in Chester Grant, Nova Scotia, Canada
Posts: 13,591
Quote:
Originally Posted by PaulS View Post
Checked, and the vacuum line ports directly into the intake manifold--specifically, the flow passage to the #4 cylinder. What would be the effect of a vacuum leak there?

-Paul
Normally the engine runs lean on all cylinders because of lack of vacuum which ups the RPM and can burn a hole in the leanest piston, #4, if you let it go on too long.

The only tricky part is if the last owner set the carb mix and idle speed up 'with' the leak present. The setting will be off after you fix it if this is the case, so if the idle drops too low you have an idea of what to go for.
__________________
Mike
86/00 CJ7 Laredo, 33x9.5 BFG AT's, 'glass nose to tail in '00, 'New' frame,wires and plumbing in '09. Carter BBD Carbed 4.0 HO in '10.
89 YJ Renegade. BBD Carbed 4.0 HO. Locked front and rear with 33x9.5 BFG AT's
Some Canadian Bush Jeep Runs and Build Photos: http://mikeromainjeeptrips.shutterfly.com (10 new albums added Sept 16/10)
Mike Romain is offline   Reply With Quote Quick reply to this message
Unread 06-05-2008, 09:56 AM   #4
PaulS
Registered User
1949 CJ3A 
 
Join Date: Jun 2008
Location: Edmonton, AB
Posts: 83
Thanks! The carb needs adjustments now anyway, so I'll deal with the leak before doing it. (I also need to put some good gas in the tank before doing the adjustments--the stuff there now is months old, and I'm sure that doesn't help the engine run well!)

-Paul
PaulS is offline   Reply With Quote Quick reply to this message
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.
Note: All free e-mails have been banned due to mis-use. (Yahoo, Gmail, Hotmail, etc.)
Don't have a non-free e-mail address? Click here for a solution: Manual Account Creation
Email Address:

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.


Thread Tools


Suggested Threads





Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.