Black Smoke

broke wagon · Post by **broke wagon** » 28 Oct 2011, 05:23

I have a 1990 240 wagon. The engine has been running fine for the past month. Two weeks ago I installed a hi-flow sport exhaust system from ipd. I am not too empressed with the exhaust.... well any way when I idle at a stop the engine idle sounds low and gives me the feeling that it's going to stall. So far it hasn't....
Yesterday I had the car parked against my garage door and noticed as I pulled the car away that it had blew black spots all over the door from the exhaust.
Also when I had drove from an idle stop I noticed through my rear view there was a plume of black smoke as I accelerated.
WTF!!!! AHHH!!!!

Could this be a rich fuel mixture???? Should I check the plugs to see if there fouled or not???? Bad injector???

Post by **jimmy57** » 28 Oct 2011, 08:38

There is likely nothing wrong.
DO you have a tachometer on the car to know what the engine speed is when idling?
I think all the things you are noticing are normal for new exhaust and performance exhaust.
I have put perfromance exhaust on lots of vehicles and there is an increase in vibration. A louder exhaust gives a tone change and you can hear individual cylinder notes that were previously run together by a more complete muffler with more baffles and sound chambers.
New exhaust of any type produces more exhausted soot since the new pipe is oily and the things that may have been absorbed on old system are spit out on cold start plus the byproducts of the oil being burned out of the piping.
As far as the black smoke, I think one part residue in new exhaust and one part you are paying WAY more attention since this sounds different and you are all fussed up with what you think is something wrong.
The new exhaust may not diffuse the exhaust like the original equipment style so the black smoke of a richer mixture (especially since the weather is cooling down and morning starts are done with progressively richer mixture with progressively colder temps) may be concentrated more where it is more visible to you in car.
IF your MPG drops drastically and the car has low power or other symptoms then I'd worry. Otherwise relax and drive it and see if in fact some of the tings you are so aware of may fade and not seem like issues in a few days.
If the exhaust is strained on the mounts you may need to loosen clamps and shake it a bit and then secure all the clamps again. The exhaust being stressed on the mounts will make more vibration and on an idling 4 cylinder engine that can be a very coarse rumble that is produced.

broke wagon · Post by **broke wagon** » 28 Oct 2011, 09:45

Thanks for the comments....
I just got back from cleaning and regapping the plugs. I also cleaned up the rotor and distrib....
No it doesn't want to start... it shakes around like there's an animal in the engine and jumps around then dies...
but now I've taking something to relax.... and I am re-looking the situation over .....
I might have to go with some new plugs and that..... I might of screwed them up while cleaning ...

I changed out the plugs with new ones... the engine starts up but still runs rough and stalls...