1999 chevrolet suburban wont start, now not firing

1999 CHEVROLET SUBURBAN
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JERONIMO
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Electrical problem
1999 Chevy Suburban V8 Four Wheel Drive Automatic

HI,
had my suburban a couple of years and has never missed a beat but
I let my suburban sit for a week whilst in hospital, on my return it hesitated then started, and did the same all day hesitated then started as if firing then not . The next day it fired but wouldnt start, then started firing intermittently....eventually it wouldnt fire at all just spin over. I towed it to my friends shop about 10 miles and when i arrived it started firing again, but still wouldnt start. The next morning it wouldnt fire again...on checking we couldnt get any spark so.. changed the cap and rotor,cam sensor,crank sensor,coil all with no effect... still no spark...I am at a loss.... anyone got any ideas?
Nov 6, 2009 at 11:19 AM
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JDL
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Welcome, did you check primary circuits at the coil. Pink wire is voltage, goes hot when you turn on the key, engine cranking there should be a pulse on the two white wires. The white wire with black tracer comes from the coil driver module.
Oct 4, 2019 at 3:44 PM
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JERONIMO
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i forgot to say, it was the whole ignition module - coil and amplifier that was changed ...will have to check again tomorrow, i know there was power to the coil with the ignition on, but didnt check it pulsing.
Oct 4, 2019 at 3:44 PM
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JERONIMO
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disconnected battery and reconnected and now the diagnostic scanner connected straight up. Keeps coming up with a 0336 fault code indicating the cranks sensor... but i know that the crank sensor isnt faulty as it has been changed onto another truck and works fine.... so still confused...
Oct 4, 2019 at 3:44 PM
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JDL
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Crank sensor may be ok, what about the wiring circuit? Ref voltage-- ground, and signal.

Did you check for a pulse, at coil primary circuits, engine cranking? You can probably use an led testlite between the 2 terminals, crank engine see if lite pulses, brightens and dims, something.
Oct 4, 2019 at 3:44 PM
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