So i have been having a problem with my 98 4.3L feeling like it was going to stall at stop lights. So i changed the IAC valve (didnt do anything else) when i started it up it would idle at 1200 RPMS (usually was 500) then drop to 650 after about 4 seconds then when put into gear it would jump back up to around 1200 then drop then again when driving all of a sudden it would take off would have to hit the brakes to bring it to normal. So i changed it back to the old one and it is idleing and driving normal, but still feels like it is going to stall. Did i forget to do something with the new one? Thanks