What are some of the main causes for vacuum leaks for the slant six.
The plugs are showing it running a little rich, and when I used the colortune to check a couple of the cylinders , it showed whiteish blue, and no matter how much I adjusted the mixture screw out it never really changed ,and never showed a yellow or orangish spark.
I sprayed some carb cleaner on the intake and around the engine , with no change in idle. Still showing a little over 15hg on vacuumgauge at idle.

Thanks for any replies
Dave

_________________
81 Dodge D150
It looked easier in the book .

Vacuum leaks can occur wherever there's a gasket junction (manifold to head, manifold to carb, in between carb castings), wherever there's a vacuum hose or connector (cracked/split), or wherever there's a vacuum-operated actuator (torn/holed diaphragm). A faulty EGR valve can admit exhaust when it's not supposed to. Less commonly, a cracked intake manifold can admit air or exhaust.

Remember, many carbs made after 1967 are designed such that the idle cannot be made substantially over-rich by unscrewing the mixture needle.

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

Thanks Dan , I guess a good way to check the hoses would be to block it off from the vacuum source ,one at a time, and see if you get an increase in vacuum.

Dave

_________________
81 Dodge D150
It looked easier in the book .

When I plugged up the bottom nipple on the passenger side that goes to the pcv valve , the vacuum went up to 18/19.I have that hose teed off to the charcoal cannisters also.When I plug up the hose that goes to the cannisters the vacuum does not raise any, and the same goes for plugging up the pcv side.The only way the vacuum goes up is to plug off that nipple.I hope this might bring on some suggestions.


Thanks
Dave

_________________
81 Dodge D150
It looked easier in the book .

I found a vaccuum leak on my slant, between the carb adapter plate and the intake.

_________________
"Ja, Ich fahre ein altes auto."
'78 Volare 225
'67 Charger 318

00spy,
I think you found your problem.........the PCV should go straight into the base of the carb at the back. It should not be "T'd" into anything.......

There is a fitting on the front from the base that goes to the canister. Take a look at the pictures of my carb on the red link below. Dan's links to the carb docs under the stickies will show you the same thing...........

Change it back to the stock configuration and your carb will work much better!

_________________
Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

…unless one is trying to run a charcoal canister with a carb not equipped with a purge port. But in that case, the canister has to be plumbed in correctly with a purge valve per this post

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

click here
sorry Dan,could'nt resist it.

regards,Rod

thanks for everyones replies, I think I am going to replace my pcv valve and see if that helps. When I take off the hose that goes to the charcoal cannister , and plug it up with my hand , it take a few seconds for the thingy inside the valve(sorry for being so technical) to be sucked up by the vacuum, and some times not at all.

Dave

_________________
81 Dodge D150
It looked easier in the book .

One more question. If I have an extra vacuum port on my intake manifold,would it better to run that to the cannister instead of teeing it off of the pcv hose?

_________________
81 Dodge D150
It looked easier in the book .

No, do not run your charcol canister directly to manifold vacuum. That will worsen things.

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

Ok. I replaced the pcv valve, and now when I block off the hose for the cannister it goes to 18hg. Now I know the vacuum leak is coming from one of the charcoal cannisters .Is there a good place to purchase new cannisters, and I guess as long as it has the same ports any would be ok.


Dave

_________________
81 Dodge D150
It looked easier in the book .

Yup, sounds like you're due for a new canister. They can't be had by application for our old Mopars, so you'll have to page thru the Standard-Hygrade fuel system parts illustrated buyer's guide (ask to see it at your stockist's). You're after a canister that has at least the same number and type of ports your present can has. Try a Standard-Hygrade #CP1014, in conjunction with the inline purge valve described at the post linked above.

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

Thanks Dan

_________________
81 Dodge D150
It looked easier in the book .

Canisters are expensive on the open market, but it looks like you can get a new CP-1014 from SOS Surplus for around $10 ; call them up and ask.

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.