Listmembers,

I wrotee about the Temp I sensor below in two previous post.  After
re-reading my original post I would like to clarify that the Temp I
sensor only indicates an "extra rich mixture by say 20% on extremely
cold mornings, say when the temperature is <32 F or 0 C.  The TEMP II
sensor Cold start enrichment is for general conditions.  I had
originally wrote to this effect and mistakenly deleted it  during an
edit.  Sorry for any confusion.

To add to the discussion regarding Temp I function on the Digifant
system during my original post:

The information I received from Darrel Boehler was that that extra fuel
enrichment is added by the ECU when the TEMP I sensor indicates near
freezing air. The ECU's map may then wait until either an indication
from TEMP II, i.e. engine beginning to warm, or just wait until close
loop before the TEMP I enrichment value is canceled out.

  Either way, Darrel "guestimated" the value to be 20% extra to the
regular cold start mixture map. It seems Darrel stated that this is the
only purpose for the TEMP I sensor.

My original post excerpted below is:

"The first clue that the fuel pressure regulator is setting too high a
pressure is cold mornings when temp I, an air temp sensor, determines if
the computer richness the mixture to start the engine.  A pressure
regulator that is beginning to get too high will cause the engine to
sound like it's running on three cylinders, or chug, and then as it
warms up and the Temp I compensation is removed, the chugging smoothes
out.  I've had this, and was related  too high a fuel pressure."

Sincerely,

Mark Keller
91 Carat
Cowichan Bay, BC