***EDIT BELOW***
OK. Made it home Wednesday night... by way of tow truck. First chance I've had to post after falling so far behind in work.
Pulled the distributor. Saw no signs of trouble.
We have family that could come get us, so I decided to try and get 'er as close to home as I could and maybe luck out.
Started off with 6 hours estimated driving time (with food, full water tank and empty holding tanks.) All good.
Got a few hours down the road and noticed some light knocking on a hill. Since I had timed by hand, I guessed it must be a little advanced.
Pulled over and retarded.
Did this several times. Knocking worsened. I would, of course pull over almost immediately upon hearing knocking.
So I guessed I must have gone the wrong way and it was actually knocking because it was over retarded.
So I went the other way and the knocking went away.
Merrily Cruising through Eugene and she sputtered HARD.. and backfired. I shut her down and coasted to the shoulder.
So I retarded the distributor further and she fired up.
Did this a few times and she ran worse and worse until finally... with distributor rotated and vacuum advance pegged into the carb...
***EDIT***
and after knocking heavily...
she was done.
We were an hour away. Girls got a ride home and I with the tow truck driver.
So...
Since my research seems to indicate that it's very possible GM was still using plastic top gears in 1986... it seems to point most clearly to a cam timing jump.
Further research indicates that the only way to truly tell... is to pull everything off the front and check the marks on the gears.
Otherwise... if it's far enough off... I might be able to tell by the valves.
A compression test should be telling... so long as the valves are OK.
Either way... if this rig has the plastic gear, I plan to do a timing chain job.
Your thoughts?
.
