If it will go into gear when the engine is off but not when the engine is running, the clutch is not disengaging. It could be the clutch, possibly warped or put in wrong, or it could be the hydraulic clutch mechanism.
The 1986 Honda Prelude does not have a clutch cable. The 1986 Prelude has a hydraulic clutch instead of the clutch cable.
Does a 1998 Honda prelude have a clutch cable
Yes it does
No, slipping is not affected by low hydraulic fluid level. The hydraulics of your clutch only DISENGAGE your clutch, they do not engage it. If it's slipping, it's either worn out, the pressure plate springs have weakened or you have oil on the clutch disk.
You can't aprrently on a hyrdraulic clutch, which these have that adjust automatically.
You have 2 switches A and B above clutch petal under dash
To adjust the clutch on a 2001 Honda Prelude, first, locate the clutch pedal adjustment nut under the dashboard. Turn the nut clockwise to raise the pedal height or counterclockwise to lower it, ensuring that there's a small amount of free play at the top of the pedal travel (about 1-2 inches). After adjusting, check the clutch engagement point by pressing the pedal; it should engage smoothly without excessive play or dragging. Finally, test drive the vehicle to ensure proper clutch operation.
The Manufacturer
85 Lude, old school cable clutch... No hydraulics (fluid)
No drop it from under the car.
You could have air in the lines
On a 1989 Honda Prelude, the clutch hose is typically located between the clutch master cylinder and the clutch slave cylinder. The master cylinder is mounted on the firewall in the engine bay, while the slave cylinder is located on the transmission. The hose runs along the chassis, connecting these two components to facilitate hydraulic fluid transfer for clutch operation. Always refer to a service manual for precise locations and diagrams.