Soot on bumper

[mazdamxstyle]

I didn't know where to post this and I miss all you guys/girls (Car was rolled a while back) I now currently own a del sol and am having engine problems with it but don't know enough about serious engine problems

The problem I'm having is that after about 2 weeks I get a pretty good buil-up of black soot coming out of my exhaust and sticking to my back bumper. I know this is probably a fuel problem, I'm thinking possibly injectors. I've tried fuel injector cleaner but it didn't do anything as far as I know. If it is injectors are they generally easy to get off and clean off a 4-banger? I also have white plugs, I think it's running lean/rich, one or the other but righ tnow I'd like my car to quit spitting black out the back. Thanks so much and sorry for posting here but everyone here is so much more helpful, and I am an old family member!

[LongJohn]

You should have bought another MX-3! (just kidding).

There are all kinds of things that can contribute to bad fuel/air mixture, and at different RPMs too. With the black soot and white plugs I would guess you are sometimes running too rich and sometimes too lean.

Are all the plugs the same? If so, I would doubt that you have a bad injector. It is not likely that all four went bad or got plugged in exactly the same way. Check out this recent post:
http://www.mx-3.com/ubb/ultimatebb.php?ubb=get_topic;f=3;t=003945

He had basically a bad fuel/air mix at certain engine loads. You should check your fuel pressure and see if something is out of tolerance. Even though yours is a Honda, I would bet the ECU is made by Denso, and that most of these controls work the same.

Good luck!