QuestionI have an 87 New Yorker with a 2.5l engine. I've had problems similar to this before but the problem I am having now is that it is running rich and I am getting the following error codes: 13, 22, 27, 52. Could this be the ECU? What else might be causing this problem?
AnswerHi Tom,
I have the same engine is an '89 LeBaron Coupe, but it has a single module engine controller rather than a split which you may or may not have depending upon when it was built in the 87 model year. The 52 should be taken at face value as correct, and I wouldn't conclude there is anything wrong with the ECU. The 13 means the MAP (manifold absolute pressure) sensor is misbehaving. That could cause the engine to be run on open loop mode to keep it going and therefore cause a too rich mixture. I would check the wiring and the vacuum line to that sensor which I believe you will find on the right strut tower. You could have a cracked or disconnected hose or compromised insulation on the wires. You could check the voltage on the violet/white wire to see if it is changing when you cycle the throttle back and forth with the engine at idle. If not then if the wires and vacuum hose check out I would suspect the MAP is bad.
The 22 says the coolant temp sensor has a problem. That is located on the thermostat box on the block between and under spark plugs 3 and 4. With the engine idling, see if when you unplug its connector (gently lift tab) the radiator fan comes on, it should. Then measure the resistance between its two pins which should run around 10-14,000 ohms when the engine is cold, and drop down smoothly to 700-1000 ohms when the engine is at operating temperature. If it doesn't then that means you will again have too rich a mixture because the controller will believe the engine is still cold. You would want to get a new sensor in that case.
The 27 code says there is something wrong with the single injector control. It is located in the throat of the throttle body and again check that its wires are not compromised due to heat damage of the insulation. It may be that the injector is failing but that is about a $150 item so you don't want to just go out and buy it. So check out those three items. Then disconnect the battery for a few minutes to clear the fault codes, except that will set a code 12 which you can ignore, and then drive it and see if the behavior changes, the codes disappear, and you mileage improves.
Roland
PS I would appreciate your rating my answer, thanks.
