Ok its a 2001 Blazer 4.3L that cranks but don't start. Will start with I am a mechanic and been doing it for 20+ years and this one has me puzzled!! When it cranks it cranks hard and kicks back and stops. At times was worried it would break the starter or break the starter ears off the block. It shows all the classic signs that it is out of time. But have checked the distributor like 5 or 6 times and its dead on. It has spark, crank signal, fuel pressure, new coil, new ignition module, new cap, rotor and wires, even pulled the timing cover to check the timing chain. Took the distributor hold down bolt out and rotated the distributor as cranking and got it to start and run. held the distributor in place and had the person shut it off. When we tired to start it, it did the same old thing, cranked hard, kicked back and would not start. Kinda leaning toward a bad ECM. I have had the battery cable off of it a couple times because I had to put 2 starters in it, cracked one and burned one up so it cleared the codes and cant get it to start at all now because it kicks back to much.

 

well there are two marks on the balancer to time by are you sure your time with the correct one....just asking to be sure to rule things out