If you've been having the car sit without getting the revs up for a consistent period for more than a few revs then you've been draining the battery with the starts and idle cycles. In other words, not recharging the battery. It's likely run down so far that it won't even activate the solenoid a little bit (the clicking noise). Start with a thorough battery charge, make sure the belts aren't slipping on the alternator. Then go from there. Avoid the temptation to start wasting money on guessing and parts replacing.