It is supposed to throw a code, but if the solenoid is just weak or worn or susceptible to cold it might not.

 

Will all these allow car it run fine after warm up, but not when cold?

 

yes

 

I give evap a test Friday, thanks,I'll let you know

 

Donbrew, Just got to check evap purge solenoid, it checks good. I pulled off tried to blow through, it wouldn't. I reconnected and put vacuum to end of valve going back to engine and valve held vacuum. Like I said once it's even a little warmed up car runs fine. Today it was 48 degrees out, started up , ran about 1 minute at 1200 rpm, then hesitated and within 15 seconds died, If I kept running at 2000 rpm for 2 minutes it idled fine. I checked for vacuum leaks by all hoses & sprayed carb cleaner by intake with no change in idle. I'm thinking vacuum leak,but I haven't located it yet.

 

Clean the throttle body with throttle body cleaner and your MAF sensor with MAF sensor safe spray.
Resist the urge to use carb cleaner!!

 

I still suspect the EVAP valve cold could influence it. They are less than $25 in stock at most auto parts stores Duralast p/n PV443.

I can't think of anything else that would be affected by the temp.

After the hesitation, did the CEL come on? Check for pending codes immediately after an episode might not cause a CEL. Is the defroster on, could be the A/C clutch/compressor? Alternato bearings making noise.

Not many places for vac leaks. Brake booster, EVAP, loose bolts on manifold/TB, cracked manifold. One member managed to break one of the vac vents on the manifold. Not like a 70's V8 with vac hoses everywhere.

 

Vapour return line could have pin holes.

 

Not a return line it is vapor from the tank. The HHR fuel system is pressure regulated so it does not use a fuel return line.

But could be pinholes in the fuel line.




BTW: for the folks that think there is a design flaw that makes the lines inherently susceptible to corrosion.

 

I have a fuel pressure gauge, I'll check. What should pressure be, I saw the test port on fuel rail, i'm guessing between 50-60 psi. Ignition on, engine off and hold pressure for about a minute within 5psi. Does that sound right??