palyado: need expert help

[cablespy]

Car: Corolla gli ae101

Symptoms:
1. palyado (intermittent)
2. mahina hatak
3. nangiginig pag may aircon
4. hirap paakyat sa incline

Service done:
1. Changed sparkplugs
2. Changed Fuel filter
3. Change oil/ oil filter
4. timing
5. cleaned throttle body, intake manifold and injectors

Problem still exists. kanina paakyat ng parking ng eastwood tinulak nalang kasi di na kaya paakyat. I've brought this to several mechanics already including casa and it's still not fixed. What is the most possble cause?

Update (april 1, 2007):

1. swapped with known good computer box- NOGO
2. swapped with known good servo - NOGO
3. swapped with known good distributor -NOGO

Problem still exists