QuestionQUESTION: I have a 1989 e150 with a 302. It runs good cold, but the check engine light flashes. Once it warms up it starts running rough (check engine light goes out), in park it runs smooth but once in gear its gets rough. Changed Plugs, wires, cap, rotor, air and fuel filters.
ANSWER: need to take it and have it scanned check engine light will be very important and i can't do that online
---------- FOLLOW-UP ----------
QUESTION: got a few codes... 12... 13.... 41....42
Answer12 and 13 are idle control codes meaning ecm can't control idle at low or high limits
41 and 42 are o2 codes one lean and one is rich very unusual to get both.
first check for vacuum leaks by spraying water or carb cleaner around engine intake/upper plenum/vacuum hoses see if engine smooths out
keep in mind if you have a misfire from a bad wire or coil carb cleaner may blow up a flame where as water won't but carb cleaner shows up vacuum leaks quicker.
check wires for o2 sensor make sure they aren't burnt on exhaust manifold or pipe
especially look for vacuum leaks
