Unstable Idle RPM while hot Suzuki Mehran 2011

[mzahid]

I am facing the issue of unstable rpm (engine vibrates) of suzuki Mehran accompanied by car turning off while braking on speed breakers.
The issue is faced only while car reaches normal running temperature and above during hot weather.

I have got complete tuning and idle rpm adjustment multiple times through the screw on back of carburetor as car is running on petrol.

Car model is 2011 and mileage 30K.

[capsat]

please share if car is running on direct fans & plain tap water in the radiator without thermostat in system. -

if SO - get a new 82 C ( 88 C ) thermostat valve [ common on PKDM Suzuki Vehicles ], flush the cooling system, put T/S valve in system, rewire fans to work on automatic & if required retard a bit ignition timing using timing light
@mzahid

Thank you @margallar for thermostat specs, suzuki Ravi & Bolan have 88 C valve

[margallar]

correction, 82 degree thermostat. it sounds like the dashpot is not working though.

[afnan.bashir]

Also car has Fast Idle valve which helps it to maintain air during the car is cold. Once it has reached its optimum level that chokes closes and air flow is restricted to be controlled by idle control valve. Now that you have messed with throttle body screw get it adjusted from 3s. All above is said considering your car is EFI one

[mzahid]

Car is running with a thermostat valve and automatic fan. radiator do have some coolant mixed with water.

please share if car is running on direct fans & plain tap water in the radiator without thermostat in system. -

if SO - get a new 82 C ( 88 C ) thermostat valve [ common on PKDM Suzuki Vehicles ], flush the cooling system, put T/S valve in system, rewire fans to work on automatic & if required retard a bit ignition timing using timing light
@mzahid

Thank you @margallar for thermostat specs, suzuki Ravi & Bolan have 88 C valve

[mzahid]

Its mehran with carburetor non-efi

Also car has Fast Idle valve which helps it to maintain air during the car is cold. Once it has reached its optimum level that chokes closes and air flow is restricted to be controlled by idle control valve. Now that you have messed with throttle body screw get it adjusted from 3s. All above is said considering your car is EFI one

[imrananr]

Its mehran with carburetor non-efi

It seems like a problem with the carburettor. Get the idle speed circuit checked and adjusted.