1988 Delta 88 3800

I have a 88 delta 88 3800. Most of the time when i start it, it wants to roar, around 2000 rpm. If I let it run long enough it will over heat and blow aintifrieeze out of the resivore. The cooling fan wont kick in and it continues to roar like it is still warming up. Ocasionally it will start and warm up and idle like it is suppost to. I have hot wired the colling fan and it works on low and hi. any one have any ideas? :banghead:

Cold engine will be around 1000-1200 rpms, but within a minute is should drop less than that, until it finally reaches normal 600-700 rpms....

If it is as high as 2000 and stays there, there are several things that can cause this....a vac leak.....a bad IAC......throttle plate is stuck open due to gunk in the throttle body,etc., .....

Scanned for codes?