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: Pull the engine codes. You can find the instruction in a haynes repair manual. Let me know what codes you find.
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QUESTION: got a few codes... 12... 13... 41... 42.
Answer12- idle control fault
13- dc motor did not move
41- oxygen sensor circuit indicates system always lean
42- oxygen sensor circuit indicates system always rich
To start with, the first two codes represent a defective idle air control valve. The other two represent may or may not be caused by faulty O2 sensors. However, the O2 sensors are cheap enough so I would recommend replacing both sensors as well as the idle air control valve. After you have installed the new parts, remove the ground wire to the battery for a minimum of 15 secs. After the codes are cleared, see if you're symptoms are gone. That should get you fixed up. Also, be sure and change the crankcase breather. It mounts in the intake below the PCV. It is commonly overlooked and needs to be replaced every 60k miles.
