I have a problem starting my car only after filling it with gas. All other times it starts normally. The GM dealer mechanics seem to be stumped with the issue. When I put gas in my car and then try to start it, i have to do the following routine. I try to start it and it stalls the first time. I then need to pump the gas while trying to start it a 2nd time. It usually starts the 2nd time, but I need to keep revving the engine for a minute or else it stalls again. One the rpm’s stabilize around 10, then it’s ok to drive. After this initial routine, all the other times i start the car are normal until the next time I put gas in it.
A second possibly related issue happens sometimes after driving on the highway. When I pull off the highway and stop at a stop light, the car sometimes seems to hiccup and then stall. It usually starts up right away and that’s the end of it. Any ideas?