Rough Idle
Thread Starter
Cruisin'
Joined: Apr 2005
Posts: 9
Likes: 0
Rough Idle
My car seems to have an idleing problem eveny once its warmed up, but its fine when its on high idle and cold. Today I started my car and in first gear it felt like the brakes were on when i was driving which was very odd. The car did not seem like it was running properly at all sputtering and spewing black smoke. I was building up boost but not going anywhere and when I let my foot off the gas i would coast normally so I know the brakes were not grabbing. I pulled off the road and when through a drive thru. This is when my car started spew massive amounts of black smoke and idle very rough. It would idle around 400-500rpm and it sounded like its wasn't running properly on all six cylinders. As soon as i would try to rev it up a bit to normal idleing range 800-900 tones of blakc smoke would come, and i mean alot. The strange thing is the other day it was acting this way but once I got it warmed up the black smoke stopped and it ran very well on boost all the way through 3rd gear and into 4th. But still when it went back to idle it wouldn't be at 800 or 900 it would sit at around 400 but there would be not black smoke.
Rennlist Lifetime Member
Joined: Jun 2001
Posts: 4,577
Likes: 9
From: Kansas City
Sounds like the cars CO is a bit off and or the warm up regulator is having issues. Black smoke is a too rich condition and will cause the car to idle strange and bellow black smoke. You need to get the mixture checked and see where it is.
You also don't mention what year the car is. If it is a 86 or newer it may be a bad 02 which causes the system to default to 45 % duty in which case may be too much mixture wise. Normally though this is shut off when the TPS sees the throttle is no longer at closed. Still something to check.
You also don't mention what year the car is. If it is a 86 or newer it may be a bad 02 which causes the system to default to 45 % duty in which case may be too much mixture wise. Normally though this is shut off when the TPS sees the throttle is no longer at closed. Still something to check.
