<<<<
Date:    Wed, 29 Nov 2006 16:09:11 -0800
From:    TC <trclark@SHAW.CA>
Subject: 85gl 1.9 running rch with the cold snap plugs  black ??

I posted this yesterday & i never showed up ..

any ways we have just got a cold snap here started van idled in the drive
way turned it off after 5 mins last night tried to start it 5 min later just
turned over so i thought maybe flooded I smell a wiff of gas anyways mess
around for 20mins then after a few more mins of cranking fires up down to
the home dump to pickup some h/w in for the store for 10 mins back out same
deal bu this time cant get it to fire just cranks & small wiff of gas so
stuff a spare plug in the #1 wire we got spark, so I pull #1plug W7DTC 3
prongits black & fouled same with all 3 others & then I C carbon build up on
the tail pipe (it was a highway run to home dump so it must be running rich
even at highway speed) so i stuff back in my old W7CO'sfires right up ...
anf fires up today

so I have a rich running issue air-filter, dist, os2, temp2, cap, rotor,
wires all new within 12mths so what am i left with over pressure regulator,
afm adjustments ??
new part crapping out in cold ??

it seems to correspond with the cold snap so what tends to fail at freezing
temps that cause rich running also on the run last night down the highway it
feel ok when running

looking for best guess here ?
>>>>>
TC,
I would look for intake(AFM connections)/exhaust manifold leaks.  It may be
that at cold temperatures, something is shrinking then expanding making a
small leak bigger, thus confusing the FI system to put more gas in to
compensate.  OK, maybe a stretch, but a confused computer can cause stuff to
work wrong.  Also check your O2 sensor and around there for leaks.  Perhaps
something you did replace is faulty -- use the Bently manual to check
resistance in the temp2 sensor and check open loop O2 sensor voltage to see
if it moves around 0.5 V.  Check your coil and coil connections.  Maybe the
plugs were all bad? (nah, not likely).  Better to methodically check
everything than shotgun it.
Rich