Question about 1990 Buick Century

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1990 oldsmobile CC SL running very rough, smoking, backfiring

I have a 1990 oldsmobile cutlass ciera SL 3.3L 150K on it running very very rough, smoking, backfiring.

when i start the car i have to push the gas pedal to the floor and then it will finally start. once running it is shaking and running like it is about to blown up, coughing and sputtering, if you increase the rpms it seems to smooth out. it is blowing all different color smokes, starts with gray, then blue, then black.... it seems to be running very very rich, aslo there is a coat of black carbon on the spark plugs when taking out... i clean them and replace and they come out dirty again.... the car drives fine if you can get it going... i scanned it many times and got no codes. the more i let the car run or keep starting the car the worse its getting. i have changed the air control, plugs, wires, air cleaner, cleaned the trottle body, check for power to all the injectors. i check the map sensor by unpluging it while the car was running and it ran worse, once plugged back in it went back to whats i said above.
any help or ideas would be great!!!!!!!!

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Well Mike" a few things to check could be Breather on fuel tank /fuel return to tank pipe/ as pump can pump high pressure and excess has to return to tank and it sounds like yours is overfueling./take air cleaner off and all pipes and check for any thing partly blocking air flow/also check any black hoses coming from the engine breathers/going to air in take/make sure all cylinders got good compression

Posted on Oct 02, 2009


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SOURCE: 1995 oldsmobile cutlass ciera

yes the part its usually at the air intake it has 2 screws its real easy to replace take the screws oput and reconnect the wiring/ Please rate my response thank you very much

Posted on Jan 29, 2009

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SOURCE: 92 cutlass ciera not starting

Sounds like it could be the fuel pump or injectors.

Posted on Dec 23, 2008

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