please help, i think my timing chain needs to be replaced

my wifes 96 blazer shut of, she was driving and it died, made a clunking noise but she was able to get it off the road. i have done alot to my truck (92) chevy, but it is alot easier to work on. she had plenty of oil, and the engine will still roll over but will not fire. i put a small amount of gas in the throtle body but it still wouldnt run, only back fired. i believe its the timing chain. how can i be sure, also is it as hard to change as it looks like it will be. i have changed mine before but like i said my engine is easier to work on than this one. i would be greatful for any help.

i just did that 1 week ago to the day. it's somewhat of a pain.

i took out the radiator, fan, water pump, alternator and bracket to get to the chain.

the timing chain cover is made of plastic, so you have to buy a new one. i bought the chain, gears and cover for 150 bucks at o'reillys.

also, you have to drop the oil pan 1/4-1/2 of an inch to take the cover on and off. (if it's 4x4, they say you have to lift the engine if it's 2wd) that's the tricky part. i loosened all the oil pan nuts and very gently pried the front of the oil pan down with a sharpened flat head screwdriver. be careful not to get into the gasket of the oil pan, or it's going to suck. i squirted some rtv where i pried it just to be safe.

you are also going to need a harmonic balancer as well as gear puller, otherwise you probably mess up the vibration damper and all that.

the timing chain is a real pain, but i'm as amateur as they come and was able to do it. just have an entire day to kill and a lot of patience.

it is a 2wd, and it looks like i have to drop the oil filter assembly to get to one of the oil pan bolts. also how do i readjust the timing after the chain is put on.

If you Put the top gear's timing mark (indented circle) to six o' clock and the bottom gears timing mark at 12 o' clock, then you can't miss. the cam shaft is keyed, so you can only put the bottom gear in one direction.

You can not adjust the timing on a 96 blazer. it's either on or off. the distributor is keyed and it will only go on 2 ways. the right way or 180 degrees off. the chain can only go on 2 ways. right and wrong. put the chain on correctly and don't touch the distributor and you'll be fine.

you should have no reason for touching the distributor in this job. also, i had the number 4 spark plug at TDC when I started working on the belt. You're going to have to pull #4 spark plug and feel for it and then check your mark on your vibration damper. the damper has 2 marks. 1 for tdc #1 and another for tdc #4. When you get all this done, i would highly recommend painting one of the marks so that you know which is which, should you need to adjust your timing ever again. I painted the groove silver and it has saved me a lot of problems (my distributor was off as well).

thanks, i am about to get the rebuild book and start working on it now.

is there any chance that this is a sensor problem, probably not with my luck.

thanks again.

i'm not sure. I was 99% sure that mine was the timing chain. i'm not a mechanic, so i wouldn't know.