99 Seville #3 cyl misfire

Tiny
KEVINLAVANWAY
  • MEMBER
  • 1999 CADILLAC SEVILLE
  • V8
  • FWD
  • AUTOMATIC
  • 145,000 MILES
I have a 99 cadillac seville sts with northstar 4.6L v8 giving me a #3 cyl misfire code. Engine idles rough and is doggy under acceleration. Any ideas?
Do you
have the same problem?
Yes
No
Monday, May 16th, 2011 AT 3:03 AM

6 Replies

Tiny
CADIEMAN
  • MECHANIC
  • 3,544 POSTS
Youll need to check the plug wire and plug. U really should scope the engine. Gl
Was this
answer
helpful?
Yes
No
Monday, May 16th, 2011 AT 4:26 AM
Tiny
KEVINLAVANWAY
  • MEMBER
  • 5 POSTS
I replaced all of the sparkplugs. All looked similar. I'll ck wires tomorrow. Are the coils or injectors notorious for going bad in these cars?
Was this
answer
helpful?
Yes
No
-1
Monday, May 16th, 2011 AT 4:59 AM
Tiny
CADIEMAN
  • MECHANIC
  • 3,544 POSTS
THEY CAN GO OUT FINISH THE TUNE UP LIKE I SAIDS U CANT FIND A BAD WIRE. YOULL NEED TO REPLACE THEM. THEY GET DAMAGED WHEN REPLACING THE PLUGS SOMETIMES. GL
Was this
answer
helpful?
Yes
No
Monday, May 16th, 2011 AT 6:17 AM
Tiny
KEVINLAVANWAY
  • MEMBER
  • 5 POSTS
Thanks for the help. I checked the injector pulse wires. They were ok. When I pulled the wires off the top of the coils to ck them, # 7 was covered with rust. Cleaned it up and regapped all plugs and now its good. Thanks again.
Was this
answer
helpful?
Yes
No
Wednesday, May 18th, 2011 AT 1:22 PM
Tiny
ALFRED022
  • MEMBER
  • 1 POST
I've have this same problem I hucked up my scanner to it and found the cylinder 3 has a miss fire, I've done a compression test which was 146 psi, I checked the injectors which are good, change the spark plugs, moved around the coil pack around to see if they were bad and there not. Also check the fuel line with a gauge and was at 45. And changed the value cover gasket. I'm stuck
Was this
answer
helpful?
Yes
No
-1
Tuesday, December 20th, 2011 AT 6:46 PM
Tiny
CADIEMAN
  • MECHANIC
  • 3,544 POSTS
Good deal kevin ty for using 2caspros
Was this
answer
helpful?
Yes
No
Tuesday, December 20th, 2011 AT 7:38 PM

Please login or register to post a reply.

Sponsored links