I recently bought a '90 honda accord. It 'had' a bad vibration at
idle, so replaced the dogbone in the front (torn rubber element) to no
avail. Then changed out the rear motor/xmission mount (what a bear)
as it was the most probable cause and found it was indeed damaged. Of
course to do this I removed the intake manifold, so had to refill the
coolant, replaced the gasket etc. Now the engine revs up to 3500 and
back down to around 800 and then goes through the cylce again. I've
triple checked vacuum runs to make sure I didn't swap something,
checked for cracked vac hoses. Can anyone suggest
something...please...I've about run out of patience.