99 #3 CYL MISFIRE

1999 Cadillac Seville

Tiny

kevinlavanway

May, 16, 2011 AT 3:03 AM

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?

FOUND 2888 RELATED QUESTIONS

Engine Miss

52 ANSWERS
12 IMAGES

6 Answers

Tiny

cadieman

May, 16, 2011 AT 4:26 AM

Youll need to check the plug wire and plug. U really should scope the engine. Gl

Tiny

kevinlavanway

May, 16, 2011 AT 4:59 AM

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?

Tiny

cadieman

May, 16, 2011 AT 6:17 AM

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

Tiny

kevinlavanway

May, 18, 2011 AT 1:22 PM

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.

Tiny

alfred022

December, 20, 2011 AT 6:46 PM

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

Tiny

cadieman

December, 20, 2011 AT 7:38 PM

Good deal kevin ty for using 2caspros

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