car starts but will not idle on 1990 Dodge Spirit

Rookie cbe0621eac06868b3efe0d8d1d3611e23c60d3114864ea2ec19a68cfbd3eebab
my 1990 dodge spirit will start fine time after time but will not run or idle, it stalls after starting. I have chaged the fuel filter , fuel pump and fuel pump filter[sock]
(2) Answers
(3) Comments
You have to have a check engine lite on. Turn the key on & off 3 times, leaving it on after the third time and count the flashing check eng lite on. The first code will be 12, the last code will be 55. If you need more help contact me at
it flashes 12 and 55 only. since this began i have changed the fuel pump and sock, fuel filter, timing belt, idle air control motor, and idle position sensor and it still does the same thing. it starts up fine but will not idle. i can keep it running but i have to feather the hell out of the throttle
It sounds like the idle air control or the Thottle Position sensor....It can be either one or both. Price for parts aprox. $100.00 plus labor 1/2 hour.Total price for both parts and labor total aprox $135.00 contact;
thanks, Im still trying to figure it out. Is there a way for me to test the idle air control and the throttle position sensor before I dish out the cash for new parts? Thanks again for your help because I am having a tough time with this problem.
changed all that and the timing belt and it still does it