2004 Buick Century

Engine Cooling problem
2004 Buick Century 6 cyl Front Wheel Drive Automatic 39000 miles

Why won't my Buick start up again after it's been run a while?
It is 2004 Buick Century V6 that starts up fine first thing when it is cool in the morning but after running
and then being parked a while won't start. The starter turns the motor, the fuel pump runs, but it won't start. If I let it sit a little while with the hood up it will start, so I'm certain it's heat related. I've replaced the battery, Vapor canister purge solenoid, vapor canister vent solenoid as well.

I am a student and I have my class start next week. I can't afford money to go to repair shop, but I will certainly donate 2Carparos to help me out. Please help me.
Sonny Singh
June 26, 2010.

First of all thank you so much for your donation. Can you go to a auto part's like auto zone and get your car scanned for code's?If you have any let me know what the number's are. Also when it doesn't start does the security light stay on or flash?

Jun 27, 2010.
I checked code with OBD-II this morning at Advance Auto's after your message and got four codes
1. P0446: Evaporative Emission System Vent Control Circuit.
2. P0453: Evaporative Emission System Pressure Sensor/Switch High
3. P0496: Evaporative Emission System High Purge Flow
4. P0651: Sensor Reference Voltage B Circuit/open

These are the same code that I recorded about week ago and I replaced these two things:Vapor Canister Vent Solenoid (rear by the gas tank) and
Vapor Canister Purge Solenoid already ( attached Pictures) but I got same issues. I drove my car Yesterday to close by Post office and It wont start now. Engine turns over but wont start. The security lights flashes all the time. Please help me.
I will be really grateful for you kindness.

Thanks in Advance


Sonny Singh
Jun 27, 2010.
What model buick century do you have?Also do you have a 3.1 or 3.8 engine. If your security light is alway's on or flashing then you need to get your body control module code's read and auto zone can't do that they can only read your engine and transmission code's. It's a more expensive and advanced scanner then they have.

Jun 27, 2010.