07 wont start with full tank of gas?

[sesnyder10]

Brand new here, so be kind if this is an old issue (I did search the archives first). I bought an 07 legacy non-turbo with 32K miles on it 2 months ago. Its my 1st subaru but 3rd problem so far (first problem was water leaking onto the passenger floormat from a plugged blower motor vent, then a cracked battery left me stranded). Now when I fill the gas tank up the car won't start without cranking for 10 seconds and pressing the gas pedal about 1/2 way.

First time this happened I put dry gas in it. After the second time it threw a code for a loose cap. So I put a new cap on it, filled it up, and it still won't start with a full tank. Any hot tips on what to look for....otherwise its going to the dealer.

I did read that on other cars topping off will cause this, but I don't top off. If its an evap purge or vent solenoid I can troubleshoot those if someone tells me location and what voltage or current to look for. Thanks

[TSi+WRX]

First, welcome.

Second - just a quick experiment: do you crank immediately after inserting the key?

If so, that might be the problem. On the BL/BP, the DBW throttle requires a little time to calibrate and the fuel-pump to prime - there's actually a whole bunch of stuff that happens from the time you turn the car "on" through the key gates to the time that you start cranking, but those two are the big ones - before the car will crank successfully.

Although on most vehicles, this just means that you crank for a bit longer (i.e. instead of the car turning over right-away, instead, you end-up cranking for 3 to 5 seconds), on some, it can mean a refusal to start, until you've turned the key back to the "off" position and tried again.

So, give this a try:

Stick the key in, and turn it to the "ON" position. Let the gauges finish their sweep, and *then* complete the key-turn stroke into the "Start" position. See if that doesn't help.

[blackfang]

Are you pressing the gas pedal and it won't start or will it not start unless you press the gas pedal?

Also definitely need to know on the above too.

[sesnyder10]

Hey thanks for the replies. Regarding the key, I don't pause to wait for the gauges to sweep but i will test the theory. The reason I don't think thats it is because the only time I have a problem is immediately after I fill the tank and put the cap back on. Last time it did this I filled the tank and then drove 4 miles to work. I shut off the car and it fired right back up with no problem. But I do need gas again so i'll try this tomorrow morning and post back the results.

On pressing the gas pedal, the first time the car wouldn't start I didn't touch the pedal. It took about 3 different 10 second cranks before it sputtered to life. So the next time I filled up and it started cranking forever I put my foot on the pedal a little.

Also, I didn't explain it clearly in my first post....but this hard start only happens right after I fill up the tank. Every other start between fillups is normal.

[sesnyder10]

An update. I filled up this morning, got back in and started the car without waiting for the gauge sweep. It started normally. Later on I removed the gas cap and tried a restart and it was normal (just removing the cap with a full tank would cause the hard starting before). The temp was about 40F when I was doing this, so i'll try again later this week when its in the 20's and see if its only a cold weather problem.

[ajmcduffie]

did you get it fixed? I have a 04 forester and had the identical problem. I know the solution. If already working then no worries. If you still need help let me know.

PS I just joined the site as a newbee as I recently purchased an 05 LGT - love it! Once you have one subaru AWD you kinda get spoiled )

[ajmcduffie]

the solution was to disconnect my purge control solenoid valve as it was bad and was flooding the engine with vapors and gas (gas from injectors along with too much gas vapor) following a fill-up. I had to crank the Forester several times before it would start. Once I disconnected the purge the car started after every fill-up thereafter. Hope this helps.

[sesnyder10]

Sorry for my lateness with the repost. I eventually figured this one out and found the same solution you did (the dealer was no help). However with the valve unplugged I got a Check engine light.

I just got a cam position sensor CE light this week. I'm afraid this is the straw that breaks me and makes me sell this car. I can no longer count on one hand the number of issues and dealership visits i've had and I haven't even owned the car for a full year yet. I'm seriously thinking its time to cut my losses and shop for a different make of car...

[Dookie]

If you plug it back in, reset the computer, drive it around for awhile, does the light come back on?