96 blazer timing off

have 96 blazer was going down road started to miss lost power then shut down. went to restart and motor is kicking back and will not start. replaced all fuel components, timing chain, distrubutor, and crank sensor. still no change. timing is advancing 45 deg. on startup causing #1 cylinder to fire on up stroke. NEED HELP NO TRUCK FOR 3 WEEKS.

was the truck running after you replaced these parts?

no nothing ever changed.

ok so back to the basics:
1. recheck thiming chain marks(make sure that #1 cylinder in on T.D.C. of the compression stroke.

2. Then make sure the distributer is pointing at #1 tower of cap.

If u feel that all the above is and has been done,keep posting with more detailed info.

timing chain and and distributor have been checked and are good. something else is causing timing to advance on startup.

You do not check it with a timing light,hook up a scan tool and go into the data stream looking for cam sensor retard,the spec is 0 degrees.The distribitor on a vortec 350,305,4.3 and 454 is set with a scan tool.

cam sensor retard is good. think we have an electical problem somewhere.