hi, I have noticed that if I start my car shorty after its been turned off, I get a quick and shakey start. but if it sits for a long time, lets say overnight, and then I go to start it, its very smooth and starts up nicely. What can be causing this??

 

Numerous items came to mind.

Spark plugs
Idle control unit
CTS (coolant temp sensor)
Fuel filter, maybe
Fuel pump, maybe

If it were mine I start with "cheap" stuff.
Spark plugs
Fuel filter
Air filter

My 3.2 did weird stuff "sometimes" after a cold start, and the temp gauge part way to "N", and I decided that a CTS (coolant temp sensor) was going flaky, I did the above 3 items first, no change, then a new CTS installed, and "sometimes" has not returned in 4 weeks, so I may have got that one right haha.