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You need to hook your hose to the "wrong good place" to operate your vacuum advance. If your hose is hooked to the port shown, it very likely could be part of your problem.
If you ever get around to checking your timing with a timing light, make sure the hose is disconnected and the port blocked. Also be aware that many people seem to mix timing covers with balancers so you need to make sure your TDC mark is really TDC on the piston.
I read that one as well and also made me thinking that must be a special kind of port it can be good and wrong at the same time
You have connected to ported vacuum as MikeM indicated. That is above the throttle plates and you are losing all of the advantages of full manifold vacuum at idle such as smoother idling and cooler temps. Here is a Quick Fuel carb (sorta of a Holley clone) on my '67 Chevelle SS-396 and you can see where I drew the vacuum from (red arrow). You can "T" a vacuum fitting off this port to read full manifold vacuum...
That labeled drawing with the "good" and "bad" text labels you shared is bad itself...
Last edited by Frankie the Fink; Apr 30, 2017 at 08:37 PM.
(there was a photo above this post that showed to hook up same like my carb now.)
Sorry, but my experiences over the last 40 years don't agree. You should try it both ways to see what you engine likes. In the 60's, full manifold vacuum to the advance unit was the norm. In the 70's, with the onset of emission standards, the source for the vacuum advance unit was moved to a source above the throttle plates, so a vacuum signal was only present when the throttle blades were opened, thereby reducing emission readings at idle. Most of my 70's and 80's pre-computer vehicles liked full manifold vacuum better. Some carbs wouldn't idle at a low enough RPM using manifold vacuum, so I had to reluctantly use the "ported" vacuum tap above the throttle blades. I never had hard starting or a starter problem, since the increased idle vacuum wasn't an issue at cranking RPM's. Of course, most of my motors back then were set to run on the 89 octane leaded fuel of the day. The crap stuff sold as regular today may not be as tolerant, so again I advise you to try both ways and see what your motor likes best.
(there was a photo above this post that showed to hook up same like my carb now.)
Sorry, but my experiences over the last 40 years don't agree. You should try it both ways to see what you engine likes. In the 60's, full manifold vacuum to the advance unit was the norm. In the 70's, with the onset of emission standards, the source for the vacuum advance unit was moved to a source above the throttle plates, so a vacuum signal was only present when the throttle blades were opened, thereby reducing emission readings at idle. Most of my 70's and 80's pre-computer vehicles liked full manifold vacuum better. Some carbs wouldn't idle at a low enough RPM using manifold vacuum, so I had to reluctantly use the "ported" vacuum tap above the throttle blades. I never had hard starting or a starter problem, since the increased idle vacuum wasn't an issue at cranking RPM's. Of course, most of my motors back then were set to run on the 89 octane leaded fuel of the day. The crap stuff sold as regular today may not be as tolerant, so again I advise you to try both ways and see what your motor likes best.
The venerable John Hinckley (JohnZ) has written many, copious articles about the advantages of full vs ported manifold vacuum... His advice trumps almost anyone else's I can think of....
Two of those articles are in this thread, but John's post may be all you need to "come towards the light"...
You have connected to ported vacuum as MikeM indicated. That is above the throttle plates and you are losing all of the advantages of full manifold vacuum at idle such as smoother idling and cooler temps. Here is a Quick Fuel carb (sorta of a Holley clone) on my '67 Chevelle SS-396 and you can see where I drew the vacuum from (red arrow). You can "T" a vacuum fitting off this port to read full manifold vacuum...
That labeled drawing with the "good" and "bad" text labels you shared is bad itself...
okay tomorrow the hose is going there and I will "T" it and give a new vacuum reading
You will need to 're-tweak' the idle speed when you do - for sure...possibly the mixture...
Read JohnZ's two articles in post #5 of the thread I cited above and quit listening to those "Hot Rod Harry" guys on other forums. I love when somebody justifies doing something wrong by citing their 40 years experience...
Last edited by Frankie the Fink; Apr 30, 2017 at 08:54 PM.
And I used the port with the metal plug in the manifold to measure vac
As I questioned on back on post 21 - you do have it hooked up to ported vacuum and if you are getting 9 inches vacuum at idle you have a carb adjustment or function issue as it should be close to or 0 vacuum.
Are you familiar with the transfer slots in the primary throat of the carb that are down by the throttle butterflies? At idle setting - choke off - where does the throttle plate set on those transfer slots? There should be somewhere around 1/3 of the slot visibly exposed. A picture down the throat showing them would help.
Actually - going back to your original question
"Some of you have read my previous thread about the fact my car idles to low and hesitates at gentle acceleration, so I bought a vacuum gauge and hooked it up to the intake manifold today. At rpm 800 I got a reading of 9 hg"
Regardless of why you have 9" vacuum at idle on a ported outlet, changing it over to the lower base plate - full vacuum port - will probably solve the issue of slow idle and hesitation by bringing in additional timing by the vacuum advance. You need to either tee off of the hose on the lower port or put a nipple in on the manifold port block off bolt. That should bring your vacuum advance in and increase your idle speed. It may increase idle speed enough that it's too high and you have to back off the curb idle setting to lower idle speed - which in turn could solve the 9 inches ported vacuum reading at idle.
Last edited by DansYellow66; May 1, 2017 at 08:13 AM.
If he was 'chasing' a good idle and got the throttle plates cracked open a bit then the vacuum starts kicking in. Personally, I'd write the 9" off and concentrate on setting up the correct full manifold vacuum tweaks...
As I questioned on back on post 21 - you do have it hooked up to ported vacuum and if you are getting 9 inches vacuum at idle you have a carb adjustment or function issue as it should be close to or 0 vacuum.
Are you familiar with the transfer slots in the primary throat of the carb that are down by the throttle butterflies? At idle setting - choke off - where does the throttle plate set on those transfer slots? There should be somewhere around 1/3 of the slot visibly exposed. A picture down the throat showing them would help.
Actually - going back to your original question
"Some of you have read my previous thread about the fact my car idles to low and hesitates at gentle acceleration, so I bought a vacuum gauge and hooked it up to the intake manifold today. At rpm 800 I got a reading of 9 hg"
Regardless of why you have 9" vacuum at idle on a ported outlet, changing it over to the lower base plate - full vacuum port - will probably solve the issue of slow idle and hesitation by bringing in additional timing by the vacuum advance. You need to either tee off of the hose on the lower port or put a nipple in on the manifold port block off bolt. That should bring your vacuum advance in and increase your idle speed. It may increase idle speed enough that it's too high and you have to back off the curb idle setting to lower idle speed - which in turn could solve the 9 inches ported vacuum reading at idle.
In post #23, OP states:
"And I used the port with the metal plug in the manifold to measure vac"
As 65tripleblack stated I did use full manifold vacuum so not ported, ans as frankie mentioned I am going to focus on getting vacuum advance to manifold connected and tuning it, after that see how it runs and what vacuum I have.
For now I am desperately waiting for a little dry weather.
I need the engine to run and I cannot run it in the garage because that would choke me within 10 minutes.
Ugh its May and this is the weather in the netherlands
Last edited by Twan Sloot; May 1, 2017 at 11:50 AM.
As 65tripleblack stated I did use full manifold vacuum so not ported, ans as frankie mentioned I am going to focus on getting vacuum advance to manifold connected and tuning it, after that see how it runs and what vacuum I have.
For now I am desperately waiting for a little dry weather.
I need the engine to run and I cannot run it in the garage because that would choke me within 10 minutes.
Ugh its May and this is the weather in the netherlands
That's 53.6 Fahrenheit. Sounds about right, but for NJ about 10 degree below "normal". It has been much too warm here all winter and spring. Global warming for sure. Global warming issue would be solved if they removed the ethanol from gasoline, and put fart bags on all the cows worldwide.
Get some flexible rubber tubing or dryer vent tubing. Run them from the exhaust out the bottom of the garage door. Use rags to seal around the tubing and the pipes, and run them at least a few feet further than the end of the door. For extra precaution you can either stuff foam, rags, towels or dead animals under the door to close the gap, although I never do that. Your results may be different. Don't try this at home. I was lucky to find two 10 foot lengths of the industrial tubing and use it.
Be sure that your vacuum gauge is accurate.
Remove one valve cover, start the engine and idle it. With the heel of your hand press down on the pushrod end of one (any) rocker arm. If that lifter starts "clacking" when you release the pressure, them you definitely have hydraulics.
Last edited by 65tripleblack; May 1, 2017 at 12:42 PM.
That's 53.6 Fahrenheit. Sounds about right, but for NJ about 10 degree below "normal". It has been much too warm here all winter and spring. Global warming for sure. Global warming issue would be solved if they removed the ethanol from gasoline, and put fart bags on all the cows worldwide.
Get some flexible rubber tubing or dryer vent tubing. Run them from the exhaust out the bottom of the garage door. Use rags to seal around the tubing and the pipes, and run them at least a few feet further than the end of the door. For extra precaution you can either stuff foam, rags, towels or dead animals under the door to close the gap, although I never do that. Your results may be different. Don't try this at home. I was lucky to find two 10 foot lengths of the industrial tubing and use it.
Be sure that your vacuum gauge is accurate.
Remove one valve cover, start the engine and idle it. With the heel of your hand press down on the pushrod end of one (any) rocker arm. If that lifter starts "clacking" when you release the pressure, them you definitely have hydraulics.
Haha, I was thinking of putting a partytent in front of the garage to solve the rain problem, but your idea is even crazier but will do the trick probably.
Dienstag
Mittwoch
Donnerstag
....
That's german btw but you probably realized that, german does sound a lot like dutch but they are different.
My dad's c1 has solid lifters which is a very distinctive sound (I like it) but this c2 doesn't have them, and besides that I don't like to remove a valve cover it doesn't leak a drop of oil now and I don't have a new gasket
Last edited by Twan Sloot; May 1, 2017 at 12:55 PM.
I'm wondering if he has the proper vacuum advance can since his was plumbed to the metered port. I guess once he gets his idle vacuum reading worked out he can check that. With the documents FTF provided he should be set to do that.
I'm wondering if he has the proper vacuum advance can since his was plumbed to the metered port. I guess once he gets his idle vacuum reading worked out he can check that. With the documents FTF provided he should be set to do that.
UGG, that's some nasty weather!
I have been askin him to check that since his first post
.
. Your results may be different. Don't try this at home. I was lucky to find two 10 foot lengths of the industrial tubing and use it.
but will do the trick probably
