1997 Oldsmobile Aurora misfiring

DANM24

MEMBER
1997 OLDSMOBILE AURORA
V8
AWD
AUTOMATIC
104,000 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

Monday, February 22nd, 2010 AT 8:57 PM

3 Replies

ERNEST CLARK

MECHANIC
1,730 POSTS

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.

Images (Click to make bigger)

Was this

answer

helpful?

Yes

No

Tuesday, February 23rd, 2010 AT 4:57 PM

DANM24

MEMBER
3 POSTS

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

Was this

answer

helpful?

Yes

No

Wednesday, February 24th, 2010 AT 8:11 AM

ERNEST CLARK

MECHANIC
1,730 POSTS

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.

Was this

answer

helpful?

Yes

No

Wednesday, February 24th, 2010 AT 3:45 PM