P0172 Buick -

Question

my 2009 buick with 3.9l starts very hard and when it does start there is a big puff of
smoke this only happens after sitting for 6 to 8 hours there is also a po172 code
please advise a solution thanks

Answer 1

HI there,

This code is for a rich fuel mixture on bank 1. With your symptoms I would suspect you may have a leaking fuel injector. After sitting for a while it's leaking fuel into the cylinder and causing it to flood. This can cause the hard starting. I would check the fuel pressure and see if it drops off when the car sits overnight and then go from there.