Hard starting and P0446 Code

I've had issues with starting my truck ever since I bought it a year ago. It always fires up, just in a struggling manner. It happens more often when I go out running errands or driving around our property, starting it on and off frequently. After sitting for a while it most often starts normally. Battery was replaced less than two years ago. I've had a P0446 code for a while now that I've mostly ignored because overall the truck seems to run well. I also have a few P301 codes but I believe they are related to the hard starts and not actually occurring during driving. The truck seems to drive fine, I do a lot of long highway driving. MPGs are good 16 - 20 depending upon circumstances. It seems I should address the solenoids and charcoal cannister for the P0446 code, but I'm curious if this has any impact on how my truck starts and how it runs. Could my starting symptoms be related to the P0446 code?

I have done the following to try to address the starting issue...

• new vacuum lines in engine
• fuel filter
• spark plugs
• air filter
• cleaned throttle body and replaced gasket
• cleaned mass air flow sensor
• replaced PCV valve and tubing
• replaced fuel cap

 

The EVAP VSS (Purge Selnoid) can throw P0446 and also flood the intake with gas vapor making it hard to start.
Try disconnecting the EVAP hose that goes from the Purge Selnoid to the throttle body while doing short runs of ON and OFF.
WARNING Gasoline vapor is HIGHLY FLAMMABLE
Clamp off open end of hose before starting engine.

 

What should I look for when attempting this? What would this tell me?

 

If the starting problem goes away it’s probably the valve

 

Had the same hard starting problems after refuelling, turned out to be something in the charcoal canisters…Replaced and solved the issue.

 

So disconnect the line from the throttle body at the purge solenoid, clamp it shut and then leave the purge solenoid open to the air?

 

you can clamp it and leave it connected or disconnect and plug both ends

 

Thank you. This is the correct line right?

 

yes

 

Is there any issue with driving with this line clamped? I figure i will try this in a few different situations to confirm it is resolving the issue. Just tried it a few times and it seemed to start more normally/consistently

 

i wouldnt think it would hurt to drive it a day or so..it may start throwing other codes though

 

You can just clamp the hose to prevent EVAP flooding the throttle body.
No need to disconnect the hose.