I have a 1999 Blazer with 118,000 miles on it. It was running fine no overheating but I noticed engine coolant leaking after short trips around town. Found where it was coming from and determined i needed to replace the lower intake gasket I put the distributer back exactly where i marked it, the engine was not moved. I put everything else back to how it was and filled it with coolant. When I tried starting it all it would do is just crank over. Then I poored a little bit of gas in the throttle body while holding it open. Waited a for a minute then tried to turn over and it finally came to life with hesitation. After doing this a couple times it starts on its own like normal, but misses at idle and when i accelerate it. And the service engine soon light came on with P0300 code.
Could I have gotten the fuel injectors dirty(spider)??

 

There could be several things,Are the plug wires in the proper order? check spark plugs (fouled)? all sensors hooked back up (cam sensor)? proper torque of intake gasket? i have also seen when the spider has been disturbed that it can leak,do you smell gas?