2001 Oldsmobile Alero cylinder 1 misfire



I have a 2001 Oldsmobile Alero. It started idling and driving rough yesterday. It has trouble with the rpm and acceleration when driving so I ran a scan and it came up as a cylinder 1 misfire. I changed all the plugs, wires and ignition coils but it is still running rough and coming up as a cylinder 1 misfire. I am at a loss as to what could cause this issue. Any help would be appreciated.


Could be fuel injectors. Switching #1 with another one and see if the problem moves to the switched cylinder.


Was the plug from #1 clean and light tan in color? Or black and sooty? Or black and oily?

@kurtwm2010 s suggestion is a good one if the #1 plug looked light tan. If its oily, you may have a valve seal or rings going bad in that cylinder. Do a dry and wet compression check to determine which.


The condition of the removed plug may have interesting clues as Mustangman suggested. I would probably do a compression test first, followed by the injector swap if compression results looked OK.