1992 Accord EX shifting very hard and vibrates at idle
This is my first post here, hoping you guys can help me out. I've been researching so long my retinas feel like they're on fire! I realize that the symptoms I'm about to explain are pretty common on these generation Accords, but I know somethings not right.
Its a 92 EX Accord, Automatic, and has 205K on the odometer.
It shifts very hard from first to second, so hard you can feel a slight vibration when it shifts, its a very snappy and firm shift. It also shifts firmly but not as hard from 2-3 and 3-4th.
As well it vibrates pretty badly in drive at around 800rpm, just a small increase in rpm up to 850-900 makes the vibrations go away.
I know about the rear motor mounts and I have not yet checked it, but I've brake-torqued the engine and I don't see the motor moving too much. I do need to check to see if the vacuum operated mount is working correctly though.
I'm planning on checking the mount to see if its operating correctly and possibly flushing the tranny with some Honda ATF. Is there anything I'm missing? I've heard the ECU's are notorious for making the tranny act up as well as the solenoids?
Also I got a check engine code #30 for A/T FI Signal, whatever that means. Code hasn't popped up again but it was there at one point.
Thanks for any pointers or help, super appreciate it!