Car wont start after pumping gas..
 

I currently own a 2006 Chevy Cobalt. For the past few months it had a problem that every time I get gas when I go to start the car up I have to pump the gas pedal and crank it at the same time to get it to start running. Once its running I have to either get driving pronto or sit and it park and accelerate it a little for a bit to keep the car running. If I let go of the gas pedal the car will clunk and shut off. If I drive off after a few blocks it’ll work fine and I won’t have the problem again until I put more gas in it.

I went to AutoZone and they told me I had a pressure thing (can’t remember fully) but to replace the gas cap. Which the car tells every so often to check my gas cap. Well 4-5 gas caps later problem still there.

Any ideas on what it could be or how to fix it, last resort is to take it to the mechanic and pay a nice bill for a fix. <O:p</O:p

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It may be related to the purge solenoid. This is just a suggestion, not a diagnosis. Consider having the vehicle inspected for an official diagnosis and repair option(s).

Please keep us posted.

Louis
GM Customer Service

post the codes that have set.

busy weekend just got back to the forum. ill take it to autozone to get the codes again. but this morning the check gas cap beep on the display again. joy... will post the codes later tonight.

ok sorry for late reply i went and got the codes for the check engine light that lady said 3 of them came up twice so the ones with (2) came up twice. if that makes sense.
p0128, p0496(2), p0442(2), p0455(2)
these are the codes in which the lady told me. hope this helps in helping me fix the problems.

the codes are for:
p0128 coolant temp below regulating range

p0442 small evap leak

p0455 large evap leak

p0496 evap purge flow during non purge request

for all the evap codes: an evap smoke/leak tester will be required to diagnose the fault. Which means dealer or independant shop.

fix the evap first as there is a reprogram available for the p0128 condition that may apply if no drivability complaints occur in conjuction with the code setting. So fix the evap first, if the car runs normal just a ecm reprogam is needed.

I have the exact same car, same year & everything and I am experiencing the same exact problem. My car wont crank after I put gas in my car unless I hold down the gas & it also tells me to check the gas cap all the time. How did you end up fixing your car?

the purge solenoid is stuck open...when you fill the tank...the fumes from the tank go into the engine through the open purge solenoid and flood the engine.

I have this exact same problem with my 07 Avalanche LT...can anyone give me instructions for (DIY) because if the purge solenoid is not too complicated to change out, I want save some money.

mine too
 

I also have 2006 cobalt, and am now having this problem. The exact same issues. So today we decided to try leaving the car on while pumping, and as soon as he took the gas cap off it killed my car. :@