Hello all. I have 1991 trooper that I just purchased and am in the process of fixing. It has the 4 cyl 2.6 engine in it. Upon starting, it starts fine, then sputters out and dies.It will also stall at lights.It will only stay running after it is warmed up some, but if i turn off hte key and try to restart it will start then sputter out and die. I have changed the spark plugs, checked the firing order, new air filter, and tried to pull codes, but all i get is code 12. When it is at full speed I get no hesitation, it runs fine, but at idle, it runs very rough. Where is a good place to start? Thank you, Jeremy Hayden