Winter gas vs summer gas

[Ludis Langens]

Has anyone here experienced problems with "winter" gas?  Especially the
oxygenated, reformulated, winter gas sold in California in (I think)
November, December, and January?

The previous two winters, the winter gas caused two of my vehicles to
occasionally ping under mild throttle conditions.  Each year, by the
time the weather warmed up enough (February) to consider diagnosing the
pinging, the problem went away.  One vehicle is PFI and the other has a
computer-carb.  A neighbor reported similar problems with a TBI engine.

This winter, I didn't have the pinging.  Instead, the carb vehicle liked
to stall when the engine was cool.  The engine acted/sounded like it
went totally pig rich, the rpms dropped, it started rich misfiring, and
eventually stalled.  I replaced a few "iffy" parts, but couldn't fully
solve the problem.  I've been driving around for several weeks with a
DVM hooked to the O2 sensor.  The DVM showed that the cool engine wasn't
nearly as rich as it sometimes got when fully warmed up.

A few days ago, I filled up with gas for the first time since January. 
(30 gallon gas tank...)  Problem solved.  Hrmph!

-- 
Ludis Langens                               ludis (at) cruzers (dot) com
Mac, Fiero, & engine controller goodies:  http://www.cruzers.com/~ludis/


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