Hello I am the original poster.
Re 2004 2.2 liter Sunfire starting and then stalling a couple seconds later after installing a new alternator.
Today, about 2 weeks after the new alternator was installed and the problem started, I tried the following, based on info I found on the internet and the car started and is running fine since. I did them all and then the car started, so I don't know which step helped, but I hope these simple steps might help others.
1- I sprayed quick drying electrical contact cleaner into the ignition key hole. I read that the 2004 Sunfire has PASSLOCK 1(no resistor pellet visable in the key) and that when the correct key is used and turned a circuit lines up and the resistance in the ignition cylinder is read and sent to the computer to allow starting, but if the contacts are corroded, the resistance is not read correctly.
2- I used a newer key (probably not worn as much)
3- This key was not on a key chain, because apparently the ignition switch resistance reader may be reading the other keys as well
4- I borrowed a computer OBD 2 trouble code reader, and plugged it in under the steering wheel, but no codes were stored. I read somewhere that clearing stored codes may fix the Passlock anti theft system, and there might even be a code(s) stored indicating what the problem with the Passlock is.
5- I lightly tapped the bottom of the gas tank. This may get the fuel pump working again for a while, if it is broken. The car has 290,000km and still has the original fuel pump. I also read that sometimes you can't hear a working fuel pump.
Thanks to all who made suggestions.
Sunday, January 6th, 2013 AT 2:34 AM