its got 170k but still running good but it shakes after 4000 rpm i don't know why,,, i replaced new engine mount, new transmission mount and new diff mount. but still vibrate hard when it goes over 4000rpm and more it shakes and vibrates hard when it keep rpm up,,, ghhhh i know i have to restore whole car but i want to fix that first. help me guys

 

Aha!! I had his same problem with my vert. Smooth until around 4,000 then it got increasingly worse over the rev range. Replaced the transmission mount (expensive $$) and tried wiggling the engine and transmission around to see if that helped... it didnt. But! Last week i took my fan off to test it (stock engine driven fan) and bam. Smooth as butter. Since I was already interested in an e-fan so I could remove the big shroud, I went to a local junkyard, found an old e-fan off a 95 villager, and shaped it up last weekend. Not that hard. I did find that the fan interferes with the stock intake pieces so I'm weighing my options there.
Hope this is your problem and not something more serious.
P.S. post technical questions in the new member technical if this doesn't help..
https://www.rx7club.com/2nd-generati...e-fan-1015973/