Help adjust distributor (1 Viewer)

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Joined
Nov 5, 2003
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Hey,
Can someone out there help me adjust my distributor? As it's getting colder up here in Maine my rig is running rough, (the cold may or may not be related, I don't know??). I have an F-engine with a vaccum advance distributor. I don't know if the advance should nearly tightened all the way in, or a couple turns out or what. I ws trying to adjust that and adjust the mixer screw on carb at same time. Is all this a waste of time unless I use a timing light?? Is there anything I can do to the distributor that would dramatically help?

Thanks,
Travis
 
you really need a timing light. YOur points prolly need adjustment(or replacement) as well.

You can try to set timing by ear, adjust(advance) till it pings under load, then back off till it stops pinging. I would set the dial in the middle, and adjust the dizzy itself.

John H
 
You also may want to clean/replace your spark plugs. You may want to check the wires as well.

I would guess it is NOT the temperature that is your problem, except it may be a little slower to warm up your engine in the morning.

I just learned that you can adjust your dizzy using a vacuum guage, and it worked well for me. Also, it is the BEST way to adjust your idle mixture, but, remember, idle mixture only affects your running at idle.
 
Dave, the vuccum method. Do you just set timming untill you get highest vacuum reading?

Thanks
John


[quote author=IDave link=board=1;threadid=7709;start=msg64640#msg64640 date=1069169363]
You also may want to clean/replace your spark plugs. You may want to check the wires as well.

I would guess it is NOT the temperature that is your problem, except it may be a little slower to warm up your engine in the morning.

I just learned that you can adjust your dizzy using a vacuum guage, and it worked well for me. Also, it is the BEST way to adjust your idle mixture, but, remember, idle mixture only affects your running at idle.
[/quote]
 
That's exactly what I did, John. Unplugged the vacuum advance, first, of course.
It was suggested to me because I live at about 5000 feet elevation, and the dealers in Denver apparently tuned these to about 3 degrees of advance because of it. That is about where I ended up with this method. I don't really know how to measure degrees of advance, but just judging by how much I turned the distributor. My points gap is at the low end of the recommended range, so that may affect just where I ended up. Don't know. Anyway, runs much better than it did with the timing light.
 
Can you describe the steps in using the vacuum guage? I've never used one before and would like to try it.
 
Well, you just hook up the guage to a vacuum hose coming off the intake (I disconnected the brake booster hose and hooked up there). Start the engine. Disconnect the vacuum advance hose from the dizzy. The engine vacuum SHOULD be 15-20 and the needle steady if everything is normal. Loosen the dizzy and twist back and forth small amounts to maximum vacuum.

Here is a good link from the tech page with all the good basics of vacuum:

http://www.ih8mud.com/tech/vacuum.html
 
[quote author=IDave link=board=1;threadid=7709;start=msg64687#msg64687 date=1069179068]
That's exactly what I did, John. Unplugged the vacuum advance, first, of course.
It was suggested to me because I live at about 5000 feet elevation, and the dealers in Denver apparently tuned these to about 3 degrees of advance because of it. That is about where I ended up with this method. I don't really know how to measure degrees of advance, but just judging by how much I turned the distributor. My points gap is at the low end of the recommended range, so that may affect just where I ended up. Don't know. Anyway, runs much better than it did with the timing light.
[/quote]


Dave, thanks, I'm gonna try it and see how it compares to where it's "suppose" to be. I just used a vaccume guage for the 1st time a month ago, I was told by someone I bought a rebuilt carb from that the carb was fine but my valve seals were leaking(cuasing it to run rich......yeah right) hooked up the vaccume gauge and it read a steady 29lbs. Tossed the crappy re-build, had a local shop rebuild mine and it runs perfect.......nothing wrong with my motor!!!!

I'm at sea-level(like within feet of the Puget Sound) so I suspect the factory specs for timing are correct......but I'm always curious ;)

John H
 
How did you adjust idle mix without one, John? (I know, it is often done by ear). I thought that article on "Vacuum 101" by Jack Conrad is really neat. Lotta stuff you can look at.
 
[quote author=IDave link=board=1;threadid=7709;start=msg64894#msg64894 date=1069208921]
How did you adjust idle mix without one, John? (I know, it is often done by ear). I thought that article on "Vacuum 101" by Jack Conrad is really neat. Lotta stuff you can look at.
[/quote]

I had the guy who rebuilt the carb adjust it on a 4 gas(is that right?) meter, thats all he does is carbs and emmsion stuff.......so I left it up to him.

I'll have to read that artical again, it's been a while.

John
 
ok, I bought a vacuum guage last night. this saturday I want to try it out. Are these the correct steps?

Run engine and get it up to normal operating temp.
Shut engine off
disconnect vacuum hose from vacuum advance on distributor (do I need to plug the end?)
Connect vacuum guage someplace on air intake (where can I do this on an F-engine 1969?) Can I test the vacuum off the PCV line?
Start engine and check vacuum guage
Unhook spring latches on distributor cover and slowly turn right or left to increase vacuum? (is that what I do?)
What about the vacuum advance on distributor? When do I turn that and adjust it, especially if it is unhooked? (I don't quite understand)
After rotating distributor cover do I turn my carb mixture screw too also increase vacuum pressure?

Thanks guys if you can check through my procedure list and correct where needed and explain some of this.

-Travis
 
You got it, except that that's an octane selector you are thinking of opposite the vacuum advance. Leave that alone during your vacuum test. You adjust that later if you have pinging during accelleration.
 
you need to loosen the distributor hold down NOT the clamps for the cap(all this does it take the cap off, no adjustment), not sure on your year if the hold down in on the block or under the dizzy(I think under)

I would put the octane adjuster dial in the middle

John H
 
Yah, what John said. The octane selector should be at zero when you are doing this part of tuning. But really, if you can remember where it is, you can just leave it alone. It is only for minor adjustments (such as if you have to change octanes on your gas). I misunderstood (didn't read carefully :-[) which clamp you were referring to, and, as John said, it would be the one under the dizzy. If it is original, it will probably look kindof like a key. You rotate the whole distributor as it sits in its hole in the engine.

Generally the carb mixture screw starts out 1 1/4 turns from closed (screw down clockwise all the way, then back out counterclockwise--carefully, you can break these ::)).
 
Travis, I think there is some confusion here as to what parts of the car you are looking at. The octane selector, and the vacuum advance are two seperate things and have two seperate functions.. The vacuum advance (where the vac line is attached) in the distributor is operated by a little diaphram in the piece directly across from the octane selector (it is advanced by vacuum from the carb). The octane selector when turned, very slightly advances or retards your timing depending on what type of gas you are using.. do not mess wit this while you are adjusting your timing. You are correct in the first couple of steps. Run the car to operating temp, shut it off, connect your vacuum gauge to something non-vital like a power brake line or something. Now, when you disconnect your distributor, make sure you cap the distributor port/line to the manifold otherwise you will get a vacuum leak. Next, loosen the clamp at the base of the distributor (right where it goes into the block) like Idave said above. You should be good to fire the car up now. There car should be running at the proper idle speed. Looking at your vac gauge, slowly turn the whole distributor (with the cap and wires and side hooks connected.. if you remove these like mentioned above, your car wont even start). Turning the whole distributor counterclockwise advances the timing. Turning is clockwise retards it.. watch your vacuum gauge when you are doing this. The highest vacuum reading while turning it back and forth should be the ideal timing setting. When you are finished, reconnect al your vacuum lines and make sure you re-tighten the distributor clamp. The end of the distributor shaft distributor drives your oil pump. If the dist. is not tightend down, it can come out on your test drive, drop oil pressure and cook the motor. Hope this helps. Post more questions if you have them.

Mike
 
That's a really good description.

Would just like to say that using this method (plus cleaning the additive crud off my spark plugs) I was able to bring my vacuum from 13 (dizzy set at factory specs) up to 17. That's a huge difference, and I can sure tell it driving up the road!!!
 

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