DFI, Batch Fire, and other myths

[Shannen Durphey]

Here's some more interesting stuff.  During this time, the only
accurate test for measuring the effectiveness of fuel additives for
preventing carbon build up on valves was developed by BMW. A test
engine was run for an period of time, then the amount of accumulation
was measured.  Don't know if anything's changed since then.
Shannen

goflo at pacbell.net wrote:
> 
> Late 80s - Early 90s BMW had a cold-engine stumble caused by intake
> valve carbon build-up. Usually went away after warm-up. There are
> walnut shell on-the-car cleaners which address this problem.
> 
> Jack
> 
> Bruce Plecan wrote:
> 
> > Is this fact?, or theory?.
> > Bruce
> >
> > >Carbon buildup on the back if an intake valve absorbs fuel.  During a
> > >transition from part to full throttle, the carbon absorbs some of the added
> > >fuel causing a momentary lean condition, just like a wet flow manifold.