1992 Buick Roadmaster Repair Question
92 suddenly idling rough with black smoke
How clong since a tune-up? Sounds like it is flooding? Check for applicable trouble codes. You can check those yourself. Use a jumper wire at the A & B terminals of data link connector, along lower edge of dash. Turn the key just till the dash lites come on, no further, no crank, Then the mil starts flashing, you count the flashes to get the codes. Your looking for two digit codes. The first code will probably be a code 12, one flash, a slight pause then 2 quick flashes. Will probably flash 3 times before moving to next code. Code 12 just means your in diagnostic mode, nothing to worry about. If there are any other codes, let us know.
The picture below is just to show location of A & B terminals.
14,457 answers provided
Probable causes of an engine running rich are as follows:
1.Excessive fuel pressure can be cause by restricted fuel return line
2.Defective Oxygen Sensors.
3.Leaking injectors and fuel pressure regulator.
4.Coolant temperature sensor out of calibration.
5.Restricted air intake system.
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