- Jul 13, 2017
@93silverlx50I do have a timing light. It's set to 9*. It was at 13* and the car behaved the same.
My Harmonic Balancer wobbles pretty good. I'm wondering if I could spun it, could that have caused the car to go into a limp mode type state and die? If I spun it, maybe it's not truly at 9*?
I don't know anything about HB or how they work...
The Harmonic Balancer is made in two pieces, joined together by a thin "sleeve" of rubber. The rubber is "bonded" under heat and pressure, similar to the way the rubber lip element of an oil seal is bonded to the outer metal channel which supports the rubber part.
Occasionally, the bond breaks on a balancer, allowing the outer ring which has the timing marks on it to rotate a bit with relation to the inner hub. Thus the indicated timing is "off" by whatever amount of "slip" has occurred between the two parts. It might be only a degree or two, or a lot, disrupting engine performance greatly. The two parts rarely are known to come completely apart; I've never seen that happen.
Only way to positively check the timing mark location is to use a dial indicator mounted in such a way that it contacts the piston in Cylinder #1, up real close to Top Center, then rotate the crank back and forth about Top Center until the indicator remains stationary for the very smallest amount of rotation. Any other "eyeball" method, like a screwdriver stuck down against the piston top can be off 20 degrees, easily.
In a 5.0 having rod length = 5.09", at 10 degrees BTDC, the piston is down from Top Center only 0.0077", that's 4 human hairs thicknesses. At 1 degree BTDC, it is down only 0.00077", 700 millionths of an inch! Obviously, neither movement of the piston can be seen by the screwdriver method, eyeballing it. imp