I have a 97 suburban, with the Vertec engine, that I drove to my shop, parked for 5 days in the rain, and now it won't start. It has spark on all 8 cylinders. Fuel pressure is at 63 psi and pouring fuel down the throttle body had no effect. The only trouble code is a bad oxygen sensor, which I don't believe would cause a no start. The security light does not illuminate and three ten minute cycles (in case the light is bad) had no effect. Any ideas on what else to check? Thank-you in advance for any suggestions.

 

How many miles? Could be a plugged cat.

 

While checking plugs and re-checking spark, I realized the spark on 2 cylinders was intermittent. New cap and rotor did the trick.

 

Thanks for the update.