Its wierd as hell and it has only done it a couple times, but i went to start the car and it started right up but it was vibrating and shaking like crazy for a few seconds then went away. I'm sure its not the motor mounts because if it was it would do it all the time( i think?).I have no idea what could cause this. Anybody have any ideas please help? it's a 90 integra rs.

 

Anybody have a Clue??

 

If the car isn't moving..and there is bad vibration it is the motor mounts. There isnt really anything else it could be. My car tends to vibrate a little more when I first crank it up and let it warm up. My motor mounts are pretty far gone and I can see the wheel vibrate but as and I get going they tend to equal the load out and the vibration goes away.