Mechanics

MISFIRING

1997 Oldsmobile Aurora

Engine Performance problem
1997 Oldsmobile Aurora V8 All Wheel Drive Automatic 104000 miles

my engine light came on and the computer says I have a misfire on cyclinder 8 and I changed the spark plugs and wires and coil pack and it still has trouble starting and lights still on
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Danm24
February 22, 2010.




Instead of replacing components, test each component until you identify the source of your trouble.

The ignition system isn't the only thing that could cause a misfire. You could also have a lean misfire, or even a fouled plug.

One of your injectors could be bad, and not spraying enough fuel to ignite. Also, one of your injectors could be leaking and sending too much fuel into that cylinder, fouling that plug and preventing it from firing. Finally, you could have excessive oil leaking past the valve guides and fouling that plug.

Ernest Clark
Feb 23, 2010.
Well it was the fuel injector no codes come up anymore lights off cars running better but the car is still having trouble starting could it be the fuel pump

Tiny
Danm24
Feb 24, 2010.
Yes, you could have a bad fuel pump. The best way to check this is with a fuel pressure gauge. Compare your readings to spec.

Your fuel pressure regulator could also be faulty. If you're having starting troubles only after the car has sit for awhile, then that could be the FPR. If you're always having trouble starting, then the check valve inside the fuel pump could be bad.
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Ernest Clark
Feb 24, 2010.

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