I need help

Hello everyone, I have a Nissan Mistral 2.7 aut. Year 1994, it began to present problems when the changes passed, it was revolutionized in motorcycles and did not enter the change in the following speed, to achieve it it must make a game with the accelerator, sometimes it worked not others, but it had to force it with a button, this is sporadic, when stopping the engine and turning on again, part without the problem, but then it is presented.
The other one is unintentive to notice that he loses strength to face any slope along the way, but by walking on the road, no force problem.
Can they guide me? I appreciate in advance

You have checked the clutch cable seems to have a route and does not end up getting out of the data you give.

I think you have a bad crushing mace and when it is heated it does not work as it should and the embroüe disk to change what uphill is slipping.

And if the vehicle is automatic more or less the same but cost you more expensive repair.
At least in Spain some sticks stick to change ram discs in uuuuf automatic boxes that pain hehehe .