too much vacuum advance?
Thread Starter
|
Senior User
Joined: Aug 2002
Posts: 108
Likes: 0
too much vacuum advance?
On a stock ford distributor, is the vacuum advance adjustable?
Here what is going on...
If I time it with the vacuum advance connected, & vacuum applied, it will idle great, but starts extremely hard. pops too early...
If I time it with the vacuum advance disconnected, it will idle great, but the second the carb puts vacuum to the advance, it advances to a point where is starts running like complete crap...
I can not find a happy medium...
ideas, anyone...............
Here what is going on...
If I time it with the vacuum advance connected, & vacuum applied, it will idle great, but starts extremely hard. pops too early...
If I time it with the vacuum advance disconnected, it will idle great, but the second the carb puts vacuum to the advance, it advances to a point where is starts running like complete crap...
I can not find a happy medium...
ideas, anyone...............
Posting Guru
Joined: Aug 2000
Posts: 1,984
Likes: 2
Madmater, the Ford VA's are indeed adjustable; I think they take a 1/8 or 3/16" allen wrench (inserted in the vacuum fitting).
By your description, you might have the vacuum hose connected to the wrong carb port. There should be no vacuum on the hose at idle, and increasing vacuum only when the throttle is opened. The stock 2150 carb port is located under the automatic choke housing. If you're running an aftermarket carb, you can check the ports for vacuum with your finger. Look for the one with no (or very low) vacuum at idle.
By your description, you might have the vacuum hose connected to the wrong carb port. There should be no vacuum on the hose at idle, and increasing vacuum only when the throttle is opened. The stock 2150 carb port is located under the automatic choke housing. If you're running an aftermarket carb, you can check the ports for vacuum with your finger. Look for the one with no (or very low) vacuum at idle.
Thread Starter
|
Senior User
Joined: Aug 2002
Posts: 108
Likes: 0
thanks, thelonerangerxlt. I will try to adjust it tomorrow. I am running a Holley 750 carb on an edelbrock torker 2 intake. I used the same distributor when I had a 2bbl on it, and didn't have this problem. The only thing I can think of, is that there is more vacuum on the holley VA port, than on the stock, or something down that road.
which way do I turn it? will clockwise increase or decrease the amount of advance?
which way do I turn it? will clockwise increase or decrease the amount of advance?
Posting Guru
Joined: Aug 2000
Posts: 1,984
Likes: 2
Madmader, the screw changes the sensitivity of the vacuum advance. Turning it clockwise will increase the sensitivity and let the advance come in sooner, and vice-versa. If you think you have too much vacuum advance coming in when starting, it must be either be too sensitive or the carb is giving too much vacuum on the port at idle. Turning it CCW will decrease the VA sensitivity and might help.....
Here's a good read about adjusting the vacuum advance.
http://home.earthlink.net/~bubbaf250/perf/perf02c.html
Here's a good read about adjusting the vacuum advance.
http://home.earthlink.net/~bubbaf250/perf/perf02c.html
Thread
Thread Starter
Forum
Replies
Last Post
ez1134
1973 - 1979 F-100 & Larger F-Series Trucks
2
May 23, 2017 06:44 AM
Jack DK
Y-Block V8 (239, 272, 292, 312, 317, 341, 368)
21
Jul 3, 2016 06:59 PM
Ford59galaxie
1973 - 1979 F-100 & Larger F-Series Trucks
21
Feb 12, 2016 05:29 PM
hooperdoski
1973 - 1979 F-100 & Larger F-Series Trucks
30
Oct 19, 2012 04:07 PM
1986F150six
1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks
10
Feb 10, 2012 08:27 PM
