1999 Isuzu Rodeo Question What is this engine rattling Noise

Engine Mechanical problem
1999 Isuzu Rodeo Question 6 cyl Four Wheel Drive Automatic 103K miles

Here is what led up to this.
First I needed to change the water pump.
Replaced the water pump and seal

Next I replaced the timing belt and I heard a spring sound go off, so I lost the timing.
Then lined up the markings and heard Backfiring through the intake.I had to do this step about 5-9 times.
I now believe the timing is on now and the backfire stopped, but now I hear rattling sound coming from the passenger lower part of the block. It sounds like a few bolts bouncing around either in the combustion chamber or somewhere in their.I also hear along with the rattling sound, sometimes a knock/slapping sound almost like metal to metal at times.
I realign the markings again and then started the engine up and don't hear any backfire's or slapping metal to metal sound, but the rattling sound is still there. Also when I go to rev the engine the engine bogs and stalls and dies. Now these are my symptons and is there any one out there that can help me. And also along with others who are experiencing the same or similar symptons.
I will also be updating periodically on my progess. Thanks.