Thread: Desmog
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Old 12-16-2010, 08:57 AM
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subzali subzali is offline
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Join Date: Aug 2005
Location: Denver CO
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After some more MUDsearch I found this thread:

Originally Posted by FJ40Jim
Recurving the dissy is nice, but not a requirement.

You should test the vacuum advance before installing the dissy. Use a mityvac (or a engine manifold vacuum source on a running engine) and apply vacuum to the advancer fittings. The inner one should provide noticeable movement of the breaker plate. The outer one will also move the plate, but only 3* of rotation, so you have to watch for it. If the inner fitting doesn't hold vacuum, or won't move, it is permissible to use the outer fitting as vac advance. It may actually work better this way on a desmogged engine.
So after I take all the rest of the emissions stuff off I'll try hooking up the dizzy on the outer vacuum connection and see if it runs better. It'll be a neat experiment...

A couple more threads:

Originally Posted by 65swb45
Opinions vary on how to hook them up when the emissions equipment is removed.

I run with the school of thought that says run all the advance you can get without predetonation.
Originally Posted by FJ40Jim
If you have a 12/78-earlier electronic distributor, it is vac advance and vac retard. The outer vac fitting is advance, connect it to ported vac on carb. Inner fitting is retard, connect to nothing.
Originally Posted by cruiseroutfit
As Jim pointed out, 78' would be vacuum advance and retard, 79' and later would be advance advance, the inner one is ~8 degrees and the outer is 4*, though I have never tested those numbers...
Also, you can visually tell if a dizzy is vacuum advance or retard because of this: if the vacuum can is facing more toward the radiator it's advance, if it's facing the firewall it's retard. Also, if vacuum is applied to an advance dizzy the contact plate will rotate CCW, while vacuum applied to a retard dizzy will rotate the plate CW. There's a lot of good info on MUD with a little searching...
Matt Miller
TLCA# 13684
1977 FJ40 2F "Brahma" + Lockright, tach, Warn 8274, FJ60 Power Steering, no more Sanden OBA (factory emissions), so Puma OBA
1996 FZJ80 1FZ-FE factory lockers + Safari intercooled turbo, Warn M12000, OEM CDL switch, cup holder, and hand throttle, Metric TLC leather, heated seats, JDM switches, Puma OBA
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Last edited by subzali; 12-16-2010 at 11:47 AM.
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