I Adjusted my valves today to .006, and when I put every thing back together it sounded fine, then once it was warmed up the car wouldnt idle, so I tried to adjust the idle, and now it will idle, but when I let off the gas the revs drop to 200rpm then go to 1200 and rest at 900, could it be an overtightend valve?

 

make sure all your hoses ae on tight and don't have holes in them