Off-Road Forums & Discussion Groups - View Single Post - AMC 360 timing issues
View Single Post
post #7 of (permalink) Old 03-24-2004, 12:10 AM
RRich
Way Outta Control
 
Join Date: Sep 1999
Location: usa
Posts: 10,815
Thanks: 0
Thanked 1 Time in 1 Post
 
Re: AMC 360 timing issues

AHA!
Bet it's simple.

The output of the pick-up coil is actually a double spike - one up, one down as the reluctor passes.
I'll bet it's out of phase. It's triggering on the wrong slope.

Somehow the wires from the pick-up coil are reversed, maybe in the harness itself. A repair was made to the harness, or the wires slipped out of the connector, then went back in wrong? Could even be the module inside is wired wrong.

Try reversing them - orange and purple wires. Easy way would be to take them out of the connector and reverse them.


Phasing -- Normally the rotor won't point directly at the tower. Notice the tower and rotor tip are wide, not made into a point.
At low speed, like idle, the rotor will be slightly offset from the tower (but not as far as yours.) The edge of the tower still closely lines up with the edge of the rotor - barely.
As you rev it and the advance operates, the rotor will become centered with the tower. At high Revs, when it's fully advanced, it will be on the other side of the tower, the opposite edges line up.

The only time you need to worry about, or adjust the "rotor phasing" is when you are running super high R's with lots of advance.
Putting it in the center at idle makes it wrong at high R's.

For example a dragster motor may run at 10,000 RPM with 55 degrees advance. Stock the rotor would be pointing too far away - the spark would have to jump too far - if they used an advance mechanism. So you adjust the phasing. But at low end, idle, the rotor's waaay off - but it doesn't run there anyway, so who cares.
To get away from that problem those motors rarely have any advance mechanism - they are just set to the 55 or whatever works best - usually determined on an engine dyno. 55 degrees will kill the rings quickly, but life expectancy is only a few passes, if you win, who cares!
Starting is a problem - usually on those you crank it up as fast as you can - then turn on the ignition.

But on our engines we shouldn't run more than a total advance of 35 degrees, so stock phasing is fine.

RRich is offline  
 
 
For the best viewing experience please update your browser to Google Chrome