I have a tacoma that has been setting up for a year or so while I've been working on the steering, body work, etc. I ran it long enough for the engine to get up to temp and it ran great. I changed the oil, replaced the neg battery cable and installed a new AC evaperator coil. When I tried to start it a week later it would just spin. After finding I have no compression on at least 2 cylinders, one on each bank, I checked the timing belt which was dead on. Next I pulled a valve cover and discovered I have multiple but not all stuck intake valves. Any ideas as to the cause? More importantly any way to free the stuck valves without removing the heads?