NEED HELP No start issue

[TerryG]

I have a 2006 Envoy Denali 4wd. It has had intermittent issues with dying and not restarting, or not starting after sitting for an hour or so (when I go on my lunch break). So far it has always restarted after sitting for an hour or so.

I pulled the following codes while it was down:

P0443
P0445
P0496
P0689
P1682
P2176

What I've been able to come up with is pointing towards the throttle body or the evap purge system. Has anyone had any experience with this before and could offer any insight or suggestions?

Thanks
Terry

 

[mrrsm]

One of our Members @C-ya had discovered THIS issue and remedied what was going wrong in THIS Thread:

P1682, P0689, P2176 codes and no start when warm

Well, the fuse block bug bit me this week. Drive to work Monday, Tuesday, and Wednesday mornings, temps in the 20s, drive home for lunch, temps in the 40s. Truck won't start to drive back to work. Cranks over strong, spins fast, no combustion. Fired right up when I got home from work, temps...

gmtnation.com

 

[Mooseman]

Forget the evap codes for now. They would not cause driveability issues.

Follow that thread that @mrrsm posted. Then after that's fixed, it may also take care of the evap codes. If not, then troubleshoot that separately.

 

[mrrsm]

Also... Time Permitting... Check Out @Realism 's Epic "Grounds" Thread and Take A Peek At Post #5 for another Weird Electrical Issue:

Electrical Ground locations

While troubleshooting a bad ground I came across some scans of the service manual regarding electrical ground locations for our platform posted on another site. This includes both short and long wheel base, as well as both 4.2L and 5.3L. Credit goes to Wex...

gmtnation.com

 

[Mooseman]

And of course the ever popular ignition switch.