Hey there, everyone. Glad to be on the forum. Brand new to the site - literally, just signed up.
Let me get right down to it. I just bought an '87 Wrangler YJ about a month ago. After a week, the motor let loose. She had a real bad knock. So out with the old, in with the "new".
I turned around and bought another motor, freshened it up and dropped it in.
I've changed over the intake/exhaust manifolds, various sensors, fuel pump, accessory system (went from a two belt setup to a serpentine system), clutch, flywheel (bought a new one for an '87) onto the "new" motor from the blown one.
The other day, I started it and it seemed to run pretty darn well for about 10-15 minutes and then it just died and won't restart now. I'm getting spark and fuel and it sounds like it wants to start, but won't.
Now, I've done a little homework on the block casting numbers and found that the "original" motor was from '81-'89. The "new" motor I put in is from '75-'79.
What, if any, differences are there between these two, seemingly, identical motors? Specifically, are the crankshafts and/or flywheels different in terms of being internally versus externally balanced? Any help that anyone could lend in terms of the minuscule differences between these two AMC 258's would be GREATLY appreciated. The more information, the better.
THANKS A MILLION, IN ADVANCE, EVERYONE.