1. What exactly causes a 13b to start up on one rotor ocasionally?
2. How hard are the 84 se 5spd trannys to rebuild?

Id appreciate any responses, I figure that its starting on one rotor maybe due to low compression or a fuel related problem, *hopes its fuel related* lol

 

Low compression would be my guess, although there's generally higher compression in a cold engine.

 

why would there be higher compression in a cold engine? I would think it would be higher in a warm engine when the seals are expanded.

 

See this thread for my 84SE 'One-Rotor-Operation' write up;

https://www.rx7club.com/showthread.p...hreadid=262634

It may also be due to one of your injectors 'leaking-down' and causing a flood condition on one of the rotors. This can only be cured through fuel injector replacement (orange-top, 680cc, Low-Impedence).

I wouldn't worry about the engine compression just yet, since it could be any number of other items. Also, engine compression goes down with a hot engine because all of the internal spring seals are compressed down and don't have the same tension as when cold. Hot-start assist is build into the ECU on the SE's to account for less fuel during startup to ensure that it doesn't flood. In extremely cold weather, compression can be so bad that the Cold Start Assist mechanism squirts 90/10 antifreeze/water into the intake to help the seals gain enough compression to fire.

Most guys remove their Cold Start System, since it's so rarely used. HTH,