1991 Oldsmobile 98 engine runs rough

1991 OLDSMOBILE 98
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1965CORVETTE
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Engine Performance problem
1991 Oldsmobile 98 6 cyl Two Wheel Drive Automatic

My 1991 olds 3800 (112000 mi) misfired last summer. I drove 15 mi home at which time it smoothered out twice for a short time. It runs quite rough. I recently replace plugs and wires - it improved slightly. I then replaced PCV valve, again it improved. It will now idle and I do not have to have my foot on the brake and gas to keep it going. Idle becomes rougher when I put a load on by putting in gear. It will idle and run but still is rough running.It is likened to the sound of a deck of card as you shuffle them. The idle has gone from a rough performance to a sputtering one.

Thank you !

Chuck
Mar 4, 2010 at 9:46 PM
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RASMATAZ
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Engine running rough or misfiring can be cause by the following:
1.Defective spark plug.
2.Inadequate spark/coil,defective spark plug wire.
3.Lack of compression
4.False air leakage.
5.Faulty fuel injectors.
6.Insufficient fuel pressure.
7.Contaminated fuel.
8.EGR valve that is leaking.
9.Oxygen sensors.
Mar 5, 2010 at 12:23 AM