Timing Advance Issues
- Thread starter Heston 79
- Start date
I measured the vacuum off the brake booster line. Warmed up it measures 20" of hg... Needle twitches a slight bit, but doesn't even wander 1/2" total.
Revved the throttle, and it drops to 0. Goes to 25 settles at 20... Seems to me that there isn't anything wrong, according to that vacuum trouble shooting video off youtube. Is the brake booster the wrong place to measure? I expected it would show me that my timing was too far advanced and the vacuum would be around 10... Am I wrong here? Shouldn't I have got some indication?
Not real sure what to do here... I thought about backing the timing off to 10 deg and adjusting the idle but I don't want to get it out of wack if its in a good place...
Revved the throttle, and it drops to 0. Goes to 25 settles at 20... Seems to me that there isn't anything wrong, according to that vacuum trouble shooting video off youtube. Is the brake booster the wrong place to measure? I expected it would show me that my timing was too far advanced and the vacuum would be around 10... Am I wrong here? Shouldn't I have got some indication?
Not real sure what to do here... I thought about backing the timing off to 10 deg and adjusting the idle but I don't want to get it out of wack if its in a good place...
Robert Kenney
Super Moderator
Back her off to 10 and re adjust the idle speed and mixture to book speed. You're going to see a drop in vacuum @ 10 but that's fine.
Scoutboy74
Moderator
Seems like pretty good vac numbers. I guess if you don't do any towing and don't get any detonation at wot bombing up a steep grade, I guess you can live with it. Its not really where I'd be comfortable if it were mine, but too each his own.
There won't be any downside to dialing it back to 10 deg? I guess worst case if it doesn't work I just put it back. I just want to make sure the timing is close to where it needs to be before I install a new carb...
I will put it back at 10 deg and up the idle and see how it does.
I will put it back at 10 deg and up the idle and see how it does.
I adjusted it back to 10 deg. Adjusted the idle to around 650. It still stumbles off idle, but is running fine. Took it for a ride. It ran as good or better than before. I checked it again when I got back. Bumped the idle up a little and the timing settled at about 9 deg.
It was far less dramatic than I expected. I feel like it is in a good place now to swap carbs.
Thank you very much for all the help. If anyone has any other thoughts or advice I welcome it. Definitely learned some things.
Again, thank you!
It was far less dramatic than I expected. I feel like it is in a good place now to swap carbs.
Thank you very much for all the help. If anyone has any other thoughts or advice I welcome it. Definitely learned some things.
Again, thank you!