Does sound you have a sealed system issue. Take compressor amp readings. Around 1.0 is good, if you are getting .6-.4, there is a good possibility. Also, unplug and plug it back in after about 10 seconds, If the compressor starts that quick your either low on freon or have a bad compressor. Remember one reason for the delay at startup is for the pressures to equalize, one of the two reasons above can explain why the compressor would start up so quick.