I have a Mercedes 1998 v230 ambient that won't idle when cold but fine when it's hot, any ideas

lots really,
scan it yet.
no year car told
no country told
answers will be hard, wrong or generic, all not good really.
what does WON"T IDLE mean
idles too fast hot or cold
idles too slow hot or cold.
stalls hot or cold.
does engine make full power hot and cold both?
??????? tell the good and bad or answers will be wrong or wild guessing./

Throttle plate may need cleaned and check your plugs.

There is a motor on the blend door that may have went bad and needs repaced this can be accessed by dropping the glove box. It is behind it.

Hi Burt, I would suggest the fitting of a replacement air flow sensor and maybe also the fuel pump. Have a diagnostic evaluation carried out first, but keep in mind that the pump output isn't recorded and sometimes the airflow does not show up as defective when it is. regards John

you have shutter actuators that are mounted externally on you heater core enclosure inbetween your dash and firewall most likely in center. if not in center then behind glove box.

Theremostat most likely stuck

Try replacing your fuel filter

indications are that they are
hard starting when cold indicates a problem ambient temp sensor or BARO sensor
These sensors report to the ECM so that the correct air/fuel mixture is set for cold starting and running---sort of like the old fashioned choke pull
have the fault codes read to determine where the faulty sensor is

Most likely low freon tripping the relay so as not to hurt the compressor. Ambient temp has alot to do with it. Low side should be pegged on the gage when reading with motor off. While running with full a/c at ilde should be arout 50 psi, at 2000 rpms should be at least35 psi. When outside temp drops it will turn the Klima relay off or when pressure drops while running it can shut off. If the pressures are correct the pressure switch on the drier could be bad.

Are you sure it won´t come on? It could be that you need to recharge the refrigerant gas in your car. If there is no gas it will only blow ambient air. I hope it helps