Firing Order

[imtb]

* Check advance at IDLE (under 900 RPM) with vacuum advance disconnected.

* Vacuum advance does nothing for full throttle (or even heavy throttle). It only affects part throttle.

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I have only about 4-5 degrees advance at idle, I am going to hookup the vacum advance and see what it does, I am also looking at the recurve kit for the distibutor.

[imtb]

I forgot to ask how do you take the part out under the rotor? It looks like it has a roll pin holding it in place.

 

First do I take out the vacum advacne, then rotor, then the stator, then the two outer screws?

[datzenmike]

Ok Datzen Mike, I think i am on to something. I've reading the hotrodders forum on Vacum advance, you may have referred to me in earlier post. Anyway, I do not have the vacum advance hooked up to the distibutor, Can I put it on the cannon intake maifold? It has spot that plugged only on one runner. Would it be better off Both runners to a T then to the vacum advance unit. How should I set up the vacum advance, Here are my current setting below.

 

My setting right now is 4-5 degrees initial advance, really rich idle. Total mechincal advance 28-30 degrees. It jumps right into the total advace as soon as the rpms climb from about 2000 rpms.

 

The car starts better with more advance but runs crappy with to much intial and total advace. I am still reading about the atrical on the vacum advance and timing but havent quite put it all together.

 

Any suggestions.

 

Do not connect the vacuum advance directly to manifold vacuum.

 

Vacuum advance should be connected to a port just above the throttle plate on a carburetor. At idle there is no vacuum because the throttle plate is closed and the engine runs at the initial static advance the distributor is set at. For an L20B this would be 12 degrees BTDC.

 

If you connect to the manifold you will have FULL vacuum advance at idle which would be 10-15 degrees? PLUS the initial static advance of 12 degrees for a total of 22-27 degrees. It probably won't run at this setting and so you would have to back the initial static timing off. When you do this the total mechanical advance is effectively lowered as well when revved up.

 

Better to leave the vacuum advance disconnected if there is no vacuum port for it.

 

Full mechanical advance is usually in the 2,000 to 3,000 RPM range.

[banzai510(hainz)]

imtb

If I was you I would swap another distributor in there instead of ripping apart your dizzy,esp if you never taken one aprt before.

Borrow one ,get another ,whatever.

 

To get the rotor out you look at the top there is a pastic cap on there. Get e sheetmetal screw or something and lift the dust cover. Youll see a phillips screw head then the rotor will come off of coarse after tou remove the plate also.

 

I have seen people hook up the vaccum advanced to the intake manifold which is a NO-NO. As Mike said its better to leave a vacuum adv disconnect at the dizzy than to hook one up at the lower intake manifold. Hook it up at the carb port or dont run it.

 

I have some Mikunis. One set has a carb vacuum adv port the other set doesnt.

Edited January 6, 2009 by banzai510(hainz)

[datzenmike]

Here's the little rubber cover, the Philips screw is under it.

 

http://i138.photobucket.com/albums/q251/datzenmike/720%20stuff/720distributor015Large.jpg[/img]"]

[imtb]

Hmm,

 

I have only 4 intial advance at idle, if I set it to 10 or 12 it makes my total advance like 40 to much. I thought if I hooked up the vacum advance this would give the 10-12 advance at idle which is what i thought it needed to get lean idle. Then when I get on it and the vacum advance drops out and I get total advacne around 30. Or I can get the same result with recurving the distibutor with new weight and springs.

 

Here is the atricle I been reading on vacum advance

 

http://www.hotrodders.com/forum/distibutor-tuning-theory-part-1-a-59033.html

[imtb]

Ok last got to fiddle with for short time. I picked up a vacuum gauage and plugged it in when I was warming it up, it cold here 30 degress. Vacuum gauage was going crazy but looks to be pulling around 17-22 hooked up to the 4th runner on the cannon intake.

 

Next I plugged in to the vacuum can and idle kicked up and sounded like a sewing machine and smoothed in out. Took it out for a quick test ride and seemed to run smoother and no pinging at WOT. Except my daughter was with me and she freaked out when I tried to get on it. Yelled at me to slow down and I was only going like 35mph.

 

I think I am going to pick up some air filter socks and put the air horns back on. I have air filters bolted on to plates without the air horns.

[ggzilla]

The vacuum diaphragm on the distributor may be bad. Last time I checked at the wreckers, 9 out of 10 were bad.

 

Connecting vacuum advance at idle should do nothing. If correctly configured and diaphragm not leaking. At 1100 rpm you should have about 6 to 14 degrees additional advance from the vacuum (depending on specific distributor year, etc)

[hang_510]

I think I am going to pick up some air filter socks and put the air horns back on. I have air filters bolted on to plates without the air horns.

put the horns on. wont solve your issues at idle though.