OK was driving down the road other day and it just died no studder or nothing just straight shut off ... would crank and crank and back fire out the intake and exhaust .... got it towed home and looked over everything i new getting right fuel pressure, spark , and nothing ... had it towed to my garage and mech looked at it for 5 hrs replaced plugs cap rotor checked compression and timing and sensors said all fuel inj were good everything checked out said he had no clue what it is and for me to come and get it ... so im at a lost now anyone else had this he said may be distributor or engine comp? i have no clue any ideas would be great appreciated .. thanks

 

I would try a new crankshaft position sensor. They can give a bad signal and actually deliver spark up to 50 deg advance during cranking causing the backfiring and no start condition.

 

big negative ... replacedcrank pos sensor and the cam sensor and still same thing happens .. any other ideas of what it could be ?

 

Back to basics... you need compression, fuel to the cylinders and spark (at the right time).
So what could be missing?

sorry for answering with a question, I'm still thinking......

Have you tried disconnecting the battery for a couple of minutes, just in case it has something to do with the theft deterent system?

 

has gas spark compression ... new plugs wires cap rotor... its just out of "sync" alot of backfire out intake and exhaustseems like its out of time but it not i dont think thegarage checked that

 

Sounds like the timing is off. I know you said that your mechanic checked the timing, but something doesn't sound right... Recently there was another member that somehow had the base timing in the PCM change.

 

hum is it easy enough to check timing on a blazer maybe i need to check it also