kancil jerks n rpm goes up n down.... HELP

[underpower]

1st, i had search everywhere on9 n its really kinda hard 2 find a definite answer to my problem...i wish sifus here can guide me through tis..~~

I drive a kancil 660M.... rpm goes crazy by jumping up n down.... from 500- 1.5k...then to 2k...randomly, perhaps theres a pattern..... after i switch on my air con....it will jump from 1k to 500...simultaneously...like wanna mati mati like tat da engine....car jerks like crazy...

i leave it for a while...i thought da engine is still cold.....after da engine is hot...i took it for a drive.

the rpm...jumps all over da place...which means....when i accelerate, it will follow the jumping rpm....making my acceleration, pickup...heavily jerky! like accelerating then suddenly brake then accelerate alot...then brake......like a bumper car tat kept on getting hit.....

pls help!!! i sent my car 2 service yesterday...i asked them 2 tune my timing....mayb they did a bad job? i need sum advice here......thanks~!!

 

[DanzEterna]

bro, it happened to me before, just that i cant monitor my rpm as my 660 doesnt have 1.
u might check
1. ensure all cable plugs are connected properly
2. change your spark plugs
3. change cable plug.
4. check distributor.