Re: alfa-digest V7 #21

[FERDINANDO DI MATEO <fredalfa@xxxxxxxxxxxxxx>]

Joe Said problem with cold and warm starting 75.   You know Joe, I hate
to hear people say they replaced a lot of parts, guessing that one of
them might be at fault.  This is wrong, one should find the problem by
testing each component to see if they meet the specifications.

I'm not familiar with tht TS engine but if it has the Bosch system in it
then I think your problem is in the coolant temperature sensor.  It is
telling the ECU that the engine is warmer than it actually is and
therefore, not getting enough fuel to start.  (resistance too low)

A trick I use is to get a trim pot of 0 to 10K ohms.  Find a male Bosch
connector to plug into the coolant temperature connector(takes the place
of the sensor) wire the trim pot to the male connector so when you plug
it in, it serves as the sensor.

If you are ready to test the circuit, read the resistance of the sensor
in the car and set the trim pot for that same resistance.  Now when you
try starting, and it does not almost instantly, dial in about another
100 ohms and try that.  Once started turn the pot until the engine runs
smooth and steady.   When you're satisfied with the result, remove the
pot and measure the resistance you find.  Get a fixed 1/4 watt resistor
and insert it in series.  I'll bet both hot and cold starting will be
fast.  OR, get another sensor with slightly higher resistance.

One thing I failed to mention is that you should pull out the
temperature sensor and make sure the unit is clean of any crud buildup.
Good Luck, Fred Di Matteo  AROC Tech advisor USA

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