Erratic timing?

[RSpengler]

I unplugged the tan wire under the passenger dash, and set my timing yesterday. After I set the timing, I plugged the tan wire back in, and just for the hell of it blasted the damper with my timing light... The timing jumps around wildly, from above 12* to 0*, just while idling (idling rough of course, cause I still dont know what the deal is)... Is this normal?
Thanks,
-Rob

 

[SeattleSy#1255]

Re: Erratic timing?

first, there are two timing marks.

second, make sure the dissy bolt is tight and correctly plaed...that thing can be a major PITA if you can't see back there and you are only going by 'feel'.

 

[QUICK STORM]

Re: Erratic timing?

i wouldn't trust the timing marks, due to the balancers being notorious for slipping. you may have to make your own timing mark

 

[RSpengler]

Re: Erratic timing?

I verified TDC by watching the valves, and looking in the #1 cyl... Im using the timing mark furthest to the passenger side when looking at both marks on top of the damper from the top of the engine, standing in front of the truck.
-Rob

 

[RSpengler]

Re: Erratic timing?

Can your distributer go bad? Not the ICM, but the distributer itself? What exactly is in the distributer that could go bad?
-Rob