Charles Sorkin wrote:
>
> Dear List:
>
> I think I've discovered why my RPMs decline after about 30-60 seconds at
> idle. I noticed that my exhaust fumes go from being invisible to slighly
> dark, and the running get rougher. I'm assuming that this is the phenomenon
> called "loading up," but I can't find any references in the manuals about
> why its happening.
>
> How do I prevent this from occuring?
What is your idle set to?
If the air flow isn't fast enough, the fuel vapour will fall out
of the mixture and collect on the walls of the manifold. Then sometimes
it'll get sucked through in globs and sheets and will cause rough
idle and black smoke.
If it's bothersome, you can decrease it greatly by raising the
idle a bit.
I think my 70 MGB was supposed to be set to 600 rpm, and it
would even idle smoothly at 500rpm. But after a minute or so
of either it would start to chug unless I "blipped" the idle
to clear it out. Annoying at stop lights, because all the
civics thought I wanted to race.
I raised the idle to about 850rpm and problem solved.
--
Trevor Boicey, P. Eng.
Ottawa, Canada, tboicey@brit.ca
ICQ #17432933 http://www.brit.ca/~tboicey/
The stoplight in front of my house is currently: AMBER
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