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View Full Version : ignition timing, carbed.



itzdave
07-14-2010, 10:32 AM
yes ive done a bunch of searching, but im still not getting solid answers...
some people say DONT disconnect the vacuum lines, some people say DO disconnect them. some say set the timing to 24 degrees, some say 15. others mention a 'RED' mark but i dont have any colored marks on my flywheel.
i pulled my dizzy a few weeks ago to change the o-ring and now im thinkin its off a lil bit. im hearing the 'metallic rattley-clacking' noise at lower rpms when under a load, and my tach bounces a lil at higher rpms, seems like i lost a little bit of power as well...

1987 dx, WAS an automatic, now a 5spd (dunno if that matters but im seeing differences)

input?

2oodoor
07-14-2010, 04:57 PM
well what is it set at now?
get a refence point and advance or retard it two degrees at a time till you get rid of that preigntion, ping which is what you are hearing.

I run mine with vacuum unhooked but I advance the base timing a bit to compensate. I may hook it back up though. If your vac advance diaphragm is not up to par it can cause wierd idle and stalling issues.

itzdave
07-14-2010, 05:02 PM
i think, if i remember correctly, it was at like 18 with the vac lines unhooked. and the vac diaphram is bueno.
no idle or stalling issues, just power loss and mpgs went down.
thanks

itzdave
07-15-2010, 03:53 PM
bump?

Dr_Snooz
07-15-2010, 06:24 PM
You set the timing with the the vac lines BOTH hooked and unhooked! With the lines unhooked (and plugged), timing should be 4 deg. BTDC. With them connected, for a non-California carb car with MT, timing will be set at 24 deg. BTDC, which also happens to be a red mark on the flywheel. If you have a California carb car with MT, set it to 20 deg. All others go to 15 deg.

If you got a flywheel like I did when you did your MT swap, then there are no timing marks on it. Good luck with that...

Not having seen an MT flywheel with marks on it, I'm conjecturing that there is a line with a "T" next to it that denotes TDC. Somewhere nearby will be another mark with a "24" next to it, assuming you got the right flywheel. If you didn't, then there could be a "15" next to it, or even a "20". :dunno:

I agree with Roodoo, though. It does sound like you are pinging, so definitely back off the advance, or buy higher octane gas. Two engines ago (*sigh*), I was pinging like crazy, but never heard it inside the car. That was a real mess.

Hope that helps.

itzdave
07-15-2010, 06:49 PM
yea man thanks! so im guessing im about 12 degress too far advaced, yea that would explain a few things... sweet, now i just gotta re-do this tomorrow and see if it helps any, thanks again...