I have a 89 Blazer with 4.3 TBI My timing chain broke yesterday morning. From what I have read, this will not damage the motor as it is non interference. However, here's my dilemma, I need some help/advice in making sure the timing will be proper when I put it back together. I already have the stuff to do it, and I know how to time it, when it's running, and no broken chain, but with the chain having broken, I need some step by step advice/instructions on how to make sure the cam sprocket and crank sprocket will be aligned properly when the new chain is put back on. I know about the timing marks on the sprocket, but how do I make sure the number 4 cylinder is at TDC? Also, how will I know the cam is positioned properly, before I start? Someone said as long as you line up the two marks, it should be good, but couldn't I be risking being 180 out if I do that? I need to get this done first thing in the morning. Any immediate advice would be extremely helpful. THANKS! Also, would someone please tell me which timing mark on the balancer is what? I have searched the internet all day to no avail. If I am looking at it from the front, with both marks at top, the left would be...? And the right? Thanks again

 

Cant be much different than a 94

 

OK. If I am correct, I should be able to set TDC on number 4 by removing the #4 plug and using a wire or dowell, and turning the crank until the piston moves the wire/dowell up. That would do it for the #4 TDC. As for the cam, If I turn the cam until the number 4 intake valve is opened, then I should be in the ballpark of where I need to be to get back on track for putting the new chain on, right? If I am wrong, please correct me. Still confused about the to marks on my balancer in regards to which is what.

 

My problem is this, the timing chain broke while the engine was running, so I am starting from scratch here. When replacing a worn chain, the timing marks are where they need to be. See what I'm getting at? The cam and crank are no longer in sync. That's what I am working on. Also trying to determine what the two marks on the balancer represent.

 

ALSO, I bought a double roller timing chain and sprocket set. This is a built motor, so I got something durable. The crank sprocket has 3 key slots. I understand how to use those. One slot is for 4 degrees advance timing. With a factory sprocket, my timing was advanced 10 degrees. If I use the 4 degree option, does this mean I will have to adjust the distributor and retard it a few degrees to make up the difference?

 

Sorry I`m late and not a lot of help

 

Well, thanks for the input regardless. Seems like the help/response on this site has dwindled over the last couple of years...

 

Sometimes people just know the answer so they dont respond. Also different people come and go, some good, some not so much

 

Got it all on, but something still isn't right... It cranks, runs, no backfires. Just running a little funny is all... Doesn't sound like it's missing or anything. Before, when I set my mark 5 degrees advanced from factory spec, it ran like a scalded dog. Now, it's almost like sluggish, but like I said starts up nicely, with a bump, like always, but something is amiss. Also, I think I may have a cracked flywheel, (harsh tapping sound loudest from torque converter dust cover, but reverbs up through engine bay almost sounds like a bad lifter, until you get down to listen underneath) but no real way to check without dropping the damn tranny. Have to have a closer look at it this coming up week.

 

Well, when I set my time at factory spec, 0 degrees, it lopes like a drag car. (Has a mild comp cam in it). When I try to advance past zero, it tries to cut out on me. When I retard the timing, it runs better... Before, when I advanced from 0-10 degrees, it would run better and stronger. If I retarded the timing, it would slow drop idle and some power... Also, I'm selling fuel from exhaust. So what's going on? Did I do something wrong?