How to set timing to t.d.c. on 1992 302 motor

Window on distributor cap is to set dwell, not timing. You can set dwell by removing the distributor cap and gapping the points to specification, then verifying with a dwell meter. If dwell is off, remove the distributor cap and adjust as needed.
To set timing, use a timing light and highlight the appropriate mark on the harmonic damper (i.e., 8 degrees BTDC). With the vacuum line disconnected from the distributor, and the engine idling at the specified speed, view the timing with the timing light and adjust as necessary by rotating the distributor. Once set, tighten the distributor hold down bolt.

well the timing on blazers are very hard to set. first there is 2 marks on the harmonic blancer. you need to mark the second mark with white paint. pull number 1 spark plug and turn the motor by hand and feel air coming out of the spark plug hole. there is 2 top dead center (1 is for the exhaust the is 180 out of timing and 2 is the intake at top dead center that is the one you want. if you take off the rotor from the distributor you will see a number 6 that has to be line up with number 1 on the distributor cap. why did he take the distributor out

pull the distributor
turn the crank to tdc compression stroke ( remove n1 plug and put you finger over the hole to get compression stroke ) line the rotor button up with no 1 plug lead
move the rotor button back about 1/2 inch and insert the distributor
as you push it in the button will move around to line up
keep adjusting the button back until it lines up
tighten the distributor down

Set the engine to the number one compression,and bring the timing mark to zero on the harmonic balancer.(or just bring the timing on the harmonic to zero). mark to match the plug wires to cap,remove the cap.(if you can remove the cap without removing plug wire) mark the rotor position to the engine using a scribe, mark the rotor to the distributor, mark the distributor to the engine using a scribe,Take the lock down bolt out and pull out distributor. when you reinstall line up all your marking and check timing.

You need to pull the distributor back out, put motor to TDC
now you say its always a tooth off...the timing chain may be alittle worn..so when you are trying to put the distribor back in ...put a socket or something... to move the crankshaft.....move it back and forth untill the distributor falls in....AT the number one plug on cap....
Hope this helps you out ??

CHECK AN HAVE TIMING BELT CHECKED,MITE HAVE JUMPED

Hi: 1st thing to do is pull #1 Spark Plug AND before you Crank The Engine PULL COIL WIRE so your car does'nt Start During Your ommpression Test.Once you have commpression coming out #1 Spark Hole.Then follow the #1 Spark Plug Wire up to the Distributor Cap-Now Mark that #1 Wire with a Marker ,Sting any Way you'll know where it is on your Distributor.Now PULL Distributor Cap and see where the Rotor Is,It should be Pointing toward that #1 Spark Plug Wire. Could be a Little Past.. If all This Lines up and Tested Out right,Then ALL you Need to Do is Clean and Mark Your Timing to What you Car is in Time, Could be TDC (TOP DEAD CENTER) or 4-8 Degrees BTDC (Before Top Dead Center.And then put coil wire in and attach your timing light to #1 Wire And Loosen the Distributor Hold Down Bracket Under Distributor.Where You Still have a Little Resistance to Move it Clock or Counter Clock Wise. Start the vehice and Slowly Move the Whole Disributor Until You Get The Timing Light At the Timing Mark you Made. Thats It. Hope this Helps You Out. From The WYOCWBOY

You should be able to put it EXACTLY where it was when you pulled it out, if not you will need to line up the oil pump shaft and then drop it in. OR You will need to get #1 cyl TDC and then set the distributor rotor to number 1 cyl on the cap. If it does not go down all the way, the oil pump drive isnt lined up and you may need to line it up with a large screwdriver OR just put the dist in where it should go and then hold pressure down on it while someone spins the engine over until it drops into place. You cannot set the timing. The distributor will need to be set using a scanner and checking "CAM ******" it should be set to "0".

get number one piston up on top dead centre, remove the distributor cap and check the rotor to see if it is pointing to the number one post on the distributor cap, if not you may have to turn the distributor to line it up or remove it and reset it in the block.
That should get it to start then you will have to put a timing light on it to set it to specs.
I am assuming it is a petrol motor as these instructions are for petrol engines

If it no longer starts, the easiest way to check for timing chain failure is eyeballing the distributor rotor. You'll need a helper.

Procedure:

• Pull the air filter assembly
• Loosen the distributor cap mounting screws. (They won't come completely out) Some distributors have 'half-twist' fasteners that look like screws. With these you push down and give it a half turn.
• Pull up on the cap and set it aside.
• In side you'll see a round plastic thing with a piece of metal going from the center to the outside. This is the rotor.
• Have your helper turn the engine over while you watch the rotor. WARNING: Keep clear of the engine while doing this. It won't start, but it can still cause damage.
• Is the rotor turning? If not, your timing chain is broken.

Hope this helps,

Mike