Hello, so we were told that our 1992 GMC Sonoma 4.3L V6 Vortec needed a new water pump and timing chain replacement. So we tore everything down and sure enough the old timing chain was extremely loose, so we bought a new chain as well as a new camshaft sprocket and crankshaft sprocket.
I'm assuming we did everything correctly until it came time to remove the old timing gears and chain, we did not find tdc we simply removed the old components and replaced with the new ones.
After realizing our mistake we looked in a Haynes manual and it told us that as long as the balance shaft gears behind the camshaft sprocket were aligned and the timing marks on the two new timing gears were aligned that we would be at tdc of the #4 piston. We think that this is where we messed up and this is why.
After finally getting the new timing components on and getting the harmonic balancer hammered on far back enough and getting everything else reattached and set up like it was before we took it all apart we went to start the truck. It turned over but it made a horrible noise, a few small pieces of rust or something burst out of the engine area and it began running extremely rough for about 3 seconds before dying.
To make things worse it sounds like timing, but then we saw smoke coming from an area we couldn't see, but it seemed like the front of the engine, not a lot of smoke but something was definitely burnt from the smell.
So my question is for those of you with more experience does this sound like we did the timing wrong? If so is there any way to diagnose and fix the timing? Thank you in advance to those of you who are willing to help.