Question about 1994 Buick Century
Engine is running rough and on the verge of stalling.
I replaced the spark plugs but the trouble is still the same.
Can you help me?
You might have your computer checked to make sure the circuit that controls egr valve is working. On my vehicle, I had several egr valves changed and failed the emissions test until I had the computer changed and the PROMS updated with the latest PROM.
The EGR valve is easy to change because it is on top of the engine. It has electrical coils that control the valve and one of the valves may be damaged where it can not compensate at idle. If the EGR is working, when the engine first starts the engine should increase in idle speed and then switch to a lower idle speed. This is part of the EGR system check and it adjusts as the engine increases in temperature.
There are several other reasons if one of the Emission sensors is faulty that may cause the rough idle. The oxygen sensor, tempearture sensor, MAP sensor,...etc. You may have a trusted mechanic attempt to read any codes on the engine.
Posted on Sep 15, 2008
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