1986 should be carburatored and it is not required. That would only apply to a fuel injected engine.
0 TDC / Top dead center.
6 to 8 degrees BTDC---- Before Top Dead Center.
Timing chain
To adjust the timing on a 1991 Chevy pickup with a 350 engine, locate the brown wire with a white stripe, which is the timing connector. This wire is typically found near the distributor on the engine harness. Once you find it, unplug it to set the timing correctly. After making your adjustments, remember to reconnect the wire to ensure the engine functions properly.
i needi have an 87 4 +cylender 2.5 Chevy s10 pickup and need the timing diagram in order to get it running. can you help?
Chain.
does not have a timing belt it has a chain
Look at this: http://autorepair.about.com/library/firing_orders/bl-fo-5830.htm
There is no timing adjustment, The computer controlls the timing.
There is no timing ajustment, Its controled by ECM- Computer.
You don't. The timing is adjusted thru the ECM.
what is initial timing on 1966 chevy 250