Vortec 350 doesn't start. Spark advance shows 0deg.

[NorthernTahoe]

1999 Tahoe 350 vortec.

Has been sitting a week or two. Doesn't start. Gas smell is coming from exhaust, so it's an ignition problem. When it's turning, scanning software shows constant 0 degrees of spark advance.

Last time the truck was started after some sitting, it had occasional stumbling on light acceleration, but it went away pretty fast, after which it started and run normally.

I think it might have had occasional kind of hard starts every now and then.

What's your first guess?
Thanks for any help!

 

[someotherguy]

I hate guessing. Test instead. Check for spark instead of assuming. If spark is weak or erratic there may be a problem with the cap (damaged internally, wet, etc.); if it's non-existent then suspect the ignition module.

Richard

 

[Supercharged111]

Don't sweat the advance, they're pretty retarded when they crank. It helps them crank faster.

 

[NorthernTahoe]

Cap and rotor contacts were in very bad condition. Started instantly after cap& rotor change.

Rearmost cap attaching screw didn't tighten to the distributor, so I replaced it with a small bolt + 2 nuts.