Will a motor from a 1994 Honda accord stick shift fit into a 1991 Honda civic automatic?

Answer 1

The short answer is "Yes". However, the swap in question is not an easy one for many backyard mechanics. In order to make the swap happen you will need aftermarket motor mounts, modified axles, a modified wiring harness, a pedal swap, a new center console (to make the shifter look right,) and an upgrade from OBD0 to OBD1.

Depending on the trim level of your 1991 Civic, you can swap motors from the same generation Civic (1988-1991) for not only a power increase, but a cheaper and easier swap. So if you have an LX, you could source a D16A6 engine from a Civic SI for a considerable power improvement, and all you will need is the motor and preferably the Engine Control Unit (ECU).

The automatic-to-manual swap will require a set of pedals from a 1988-1991 Civic, a manual transmission for the motor you have or want to use with shift linkage, all clutch components with lines and cylinder(s), and an ECU designed for both your motor and transmission.