88 integra coolant temp sensor???

[tennykimble]

i have an 88 acura interga, -- inline 4 cyl >< dual overhead cam-- that has VERY hard starting ( very long crank time ) i have been over (and over) (and over) this thing trying to find my problem but no dice!

cam timing is good. ( all the marks line up)
ing timimng is good,
(i checked it after i got it to start and idle on a 45 degree day)
good spark,
good compression 180 +- 30 ( each cyl )
fuel pressure is good ( around 40 psi @ cranking)

i have put ( new ) in car
plugs, wires, coil, fuel filter, ign control module.

it seems like the colder it gets the harder it is to start ( & keep running )
the only thing i can think of is the timing advance / retard unit is not working??? the book says that is compouter controlled ?? but i am thinking maybe its the coolant temp sensor send a bad ( or non exsistant ) signal.
so my next question is WHERE IS THE COOLANT TEMP SENSOR on this thing??? i cant find it!? any info is appreciated THANKS!!