Rough idle

[cozmo_im]

Hello to you all!

I have 1990. Corolla with 2E (1300, 12V) carburetor enginge, 140.000km and recently my idle become unstable and roguh. But, sometimes it's working great, when you throttle UP, idle will fall rapidly and whole engines shakes, like it works on 3 cylinders... then you again throttle up and idle becomes VERY VERY fast (like automatic choke), then again normal... Also, on cold start, sometimes my automatic choke will not come on... an idle is very rough first 1-2 minutes... sometimes I cannot start the engine from first attempt (but in second attempt it starts great). Also, sometimes, when idle is normal... engines is shaking a little bit, like the fuel or spark is not stable... sometimes it works perfect. BUT, engine is running GREAT in acceleration or when you drive - perfect sound (very quiet), no misfire, no hesitation... very good acceleration without ANY jerks... smooth across whole range of accelerations and gear shiftings... problem is only on idle...
I am suspecting on my carburetor and choke/idle settings? Could it be also spark cables or distributor cap? I've changed some 3000 km ago fuel filter, spark plugs... but not the cables and distributor cap (Air filter is clean). Last year I've changed ignition module (ignition coil and distributor are great)...
I don't have RPM gauge so I cannot tell what's the difference in RPM's...
Could it be fuel? I've heard that PCV valve can mess up on idle...

Thanks in advance...
Ivan

[cozmo_im]

Replying to myself

It was some dirt in the fuel

I've filled up the tank, and the rough idle problem is gone....

[TheForgottenAE94]

Thanks for that self reply...Imma gunna try that too!