Hard start sometimes after getting gas

[Dee311]

My 2004 forester is our spare vehicle and I never fill it up completely. Just get a few gallons anytime I get gas. Sometimes it doesn’t want to start after getting the gas. Need a few tries to start or it will start but run really poorly for 5-10 seconds then idle normal. Any ideas on the issue? Saw some info online about a purge valve solenoid or something. Is that under the hood or in the back near the filler?

 

[Ultrarunner22]

I am having the same problem with my 2004 Forester XT.
The OBD also throws a P0457 (evap) code.
Had the car in shop for 10 days. Replaced Purge valve (diaphragm only,), & fuel cap. Did not replace Purge Valve Solenoid, which is located next to the Purge Valve diaphragm. The two are connected with hoses, and very difficult to reach the solenoid.
Problem still exists, but was able to pass inspection after driving 50 miles to get OBD 'ready', but with Evap showing incomplete - they will pass if only 1 diagnostic is inc.

Mechanic thinks possibly purge valve solenoid, but I have already tested it by applying 12V to the terminals, and hearing a clicking. Don't know whether that really indicates that the solenoid is good.
Canister vent valve is also a suspect, but somehow, I don't think that would cause the rough idle and stalling after refueling.
Canister itself might have a leak, but mechanic performed 'smoke-test' and could not detect any leaks.

In addition to refueling, I have rough idle/stall sometimes when vehicle is hot - especially if I shut engine off for a few minutes, then restart. That happened to me while on line at inspection station last week, so just kept the engine running.

I am planning to 'poke around' myself over the next few days, and will post any findings.

Good luck
Ultrarunner

 

[Dee311]

So do you think it is the purge valve solenoid? Is that the part under the hood? Looking up a photo of it online I can locate that part under the hood. Looks like it’s difficult to get to to change but not impossible.

 

[Ultrarunner22]

I tested the purge valve solenoid myself, by removing the entire solenoid, taking it to my workbench, then applying 12V to the pins. The valve clicked when power was applied. This test can only confirm that the solenoid is not stuck, but may not indicate that it is good.

I also checked the canister vent solenoid the same way (except that I didn't remove the solenoid; I just brought out a 12V, 1A wall-wart to supply the power), and heard the clicking from it as well.

Warning: If you choose to do these tests yourself, do not use the car's battery as a power source, unless the + lead is fused (I would recommend a fuse of 1A), to prevent possible injury and/or damage if the leads from the battery are accidentally shorted. The pins on the purge valve solenoid are difficult to reach, so I actually removed the solenoid, and brought it inside to test on my workbench. It was a bear to re-install, so I don't recommend removing it.

The CEL is not lit, and I haven't checked for the P0457 pending code within the past week, but plan to re-check periodically. If the code doesn't repeat, it should be erased from the pending memory without ever being stored (and turning on the CEL).

Unfortunately, I don't drive the car much, so I have to wait longer than expected to see any results/changes.

Hope this is of some help
Ultrarunner