Hi all, I've had a fun time playing mechanic for a couple of months. I have a 1995 LT1 with ~80k miles. I've drained the coolant, broke a knock sensor (replaced both now), and removed the water pump trying my best to divert it away from the Opti. Before refilling with coolant, I wanted to check to make sure that the car still ran so that I could confirm that the Opti was unharmed. I did this with the pump and serpentine belt off, as I read that this is okay just for a quick check. However, it doesn't start... I tried three times; twice it just cranked for a few seconds, and the third time I took a video (see below). I don't even know if it actually started, but if it did, it died quickly with a concerning noise. I've checked to make sure that no hoses or wires were caught in the crank pulley. Also, all electrical harnesses were connected except for the coolant temp sensor. I'm hesitant to try and start the car again in fear of damaging something, so I'm wondering if anyone has any advice on what might be wrong and what to do next.

Video I took:

You Tube

Here are some things to consider:
- Voltage with key in run position reads ~10.5
- The car has not run in about 3 weeks, but the battery has been disconnected (could it still be drained?)
- There were no issues with the knock sensors prior- I just broke one loosening it (with no coolant, are the knock sensors unable to function properly? Could this lead to damage?)
- When running, there was a very subtle variation in idle speed
- When running, there was an occasional H64 code (right O2 sensor lean, probably unrelated)
- There are no DTCs currently stored
- There is sludge everywhere

Thanks in advance

 

Never mind, I'm awesome at playing mechanic- I put the serpentine belt on and it started up quickly! I guess the battery was too low to run the car without the alternator.