No crank-kick back- backfire

[chevy-powahz]

Hard crank-no start-backfire-grinding of starter-motor binding up-

Replaced the crankshaft position sensor-

But at this point the same symptoms happen unless the #8 plug wire is off the plug. In which case it will just crank right up. Any ideas?

[slows10]

Is this a v6 or v8 vortec? What year? What application? Modifications? Post tune. You left out alot of info. Is the starter good? Battery? Edit, sorry I see it is a V8.

[chevy-powahz]

Is this a v6 or v8 vortec? What year? What application? Modifications? Post tune. You left out alot of info. Is the starter good? Battery? Edit, sorry I see it is a V8.

Sorry-

99 vortec 5.7- no mods-and yes new starter- precission mounted.

[joecar]

Check for clogged cats and for crank/cam timing.

[docjones804]

My truck did the same thing. after beating myself up i found that a simple high quality cap and rotor cured it. It actually started binding during cranking, surging, missing like crazy...... about 20 miles after I replace the cap and rotor. after i went and purchased the Delco set it was fine. the cap will fail and allow for cross firing between cylinders through the inside of the distributor cap. I always carry a spare now for this very reason and never buy the off brands any more. same goes for my boat that did the identical thing as well.
Good luck.

[docjones804]

check the dist cap. we had three in a row do exactly the same thing that your describing right out of the box. they can crossfire internally.