Hello here is description of my problem hope someone can give me some guidance. I have a stock 1999 blazer 4.3L. Was driving down the road and it just died. No spitting sputter or anything just died. Had it towed hope and started troubleshooting. So far no luck. Here is what I have done after searching many forums here. I have done fuel pressure test and leak back. Fuel pressure 59 psi and stayed above 55 for hours. I have checked spark at coil and spark plug. Have good spark at both places. I replaced the dist cap and rotor anyway, still same symptom of turns over but wont start. Checked spark again after replacing cap and rotor and it seems good. Put some starter fluid down throttle body and tried it but didn't even fire. I tried a new ECM that i know was good from another blazer. Same result turns over but no start. When it turns over is sounds normal so i don't think timing chain broke. It has no codes and i don't know what to try next. Any suggestions?