97 Bonneville New Fuel Pump = High Idle

Hello, I have 1997 Bonneville that needed a new fuel pump installed. I installed it along with a new fuel filter and an oil change. After starting it up the engine idled at about 1500rpm. I kinda rapped the pedel a touch and it stayed at 2000rpm. After a test drive the idle returned to normal rpm. The next morning on a cold start it happend again with the idle being 1500rpm and it wouldn't idle down for about 10miles. It did this for a couple days and I replaced the fuel pressure regulator, which helped, but it also got warmer out. Now we have another cold snap and the engine is back to idleing at 1500-1800 rpms until I drive about 15 miles and then it idles down and runs normal. In the afternoons it idles high but idles down quicker. I am also having problems with getting heat in the car. It acts like the diverter door isn't moving into position. Am I looking a vacuum leak somewhere or is there any other thoughts? -Thanks Ken