Volvo: Volvo 850 hard to start., volvo 850 glt, volvo 850

Question
QUESTION: My 1996 Volvo 850 GLT wagon does not want to start at all in the morning, but when I plug in the block heater for half an hour it starts fist shot and restarts fine all day. I changed the plugs, distributor, rotor, and air filter. The car runs smoother, but the starting problem is unchanged.
ANSWER: Adam,
Change the oil to synthetic 5W30 and put in the Volvo spark plugs for the car, and a new fuel filter. Try that. See if there any codes that may be stored in the system that would identify a possible starting problem.

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QUESTION: Ray I use only synthetic oil and I have 5W30 in the car right now. The spark plugs I changed few weeks ago are original Volvo from the dealer. The check engine light does not come on. Would the codes be stored without the check engine light? I have new Bosh fuel filter and I will install it this weekend. Could it be the coolant sensor? Regardless of the outside temperature, even above freezing the car will start only when I connect the block heater for about 45 minutes, but then it runs fine and restarts throughout the day without any problems.  

Answer
Adam,
There might be a code store it would not hurt to check. If the coolant sensor was out of range it would set a code 123.
That could then send the control unit wrong information of
the engine temp and cause hard starting. Is it possible that the compression is so low it is having diffucllity starting.