AstinaGT Forums - View Single Post - 2003 323 Sp20 rough idle and carbon spitting exhaust

zazman777 · 24-04-2015, 04:23 PM

My 2003 Mazda 323 SP20 is having some issues at the moment. It idles rough once the engine has warmed up. It starts up and runs smooth then after 10 minutes of idling it gradually gets worse shaking a bit. Every now and then it does a big drop in rpm for a second then goes back up. The exhasut smells very fumey and is spitting out black carbon stuff. This has started after i have been to the mechanics. I changed the air intake from an aftermarket one to the stock one about a week ago. then went to the mechanics to fix a misfire in the engine. They changed spark plugs and leads and ignition coils. This fixed the misfire but now it has a rough idle. The black carbon would sometimes happen after being driven a bit harder than usual but now does it just from idling. Is it running too rich and need some tune up or something.
Any help would be appreciated.
Thanks.

24-04-2015, 04:23 PM	#1
zazman777 Junior Member Join Date: Apr 2015 Location: Australia Car: 2003 Mazda 323 SP20 Posts: 3	2003 323 Sp20 rough idle and carbon spitting exhaust My 2003 Mazda 323 SP20 is having some issues at the moment. It idles rough once the engine has warmed up. It starts up and runs smooth then after 10 minutes of idling it gradually gets worse shaking a bit. Every now and then it does a big drop in rpm for a second then goes back up. The exhasut smells very fumey and is spitting out black carbon stuff. This has started after i have been to the mechanics. I changed the air intake from an aftermarket one to the stock one about a week ago. then went to the mechanics to fix a misfire in the engine. They changed spark plugs and leads and ignition coils. This fixed the misfire but now it has a rough idle. The black carbon would sometimes happen after being driven a bit harder than usual but now does it just from idling. Is it running too rich and need some tune up or something. Any help would be appreciated. Thanks.