High idle at first start
 

This is regarding mb 88 300e high rpm at cold start and rpm goes up to 1500 and come down to stall car. I did check my ovp fuel relay new cis sensor new spark plugs new ignition wires new rotor and disterbuter cap, and car still having high idle . If i disconnect icv . rpm stay around 4to 500 rpm . i was reading some post saying that icv is connected to tps . i would be really thankful for any expert advice on this issue . and also getting code 4 which is link to mass air flow sensor. On these cars their is no mass air flow sensor , if there is any can someone please tell where to look for :(

I am confused, if you disconnect the ICV (idle control valve) does the rpm change?

Gilly

icv
 

I would suspect a sticking ICV as the drop in RPM"S indicate a form of working condition. The best clean is remove the two pipes give the ICV a thorough cleaning with carb cleaner ,next should be a cleaning of the air intake bore ,if you keep the throttle in full open position you will be able to clean right to the end of the butterfly area. check for operation of the idle switch connector,clean.Hopefully this will get you started on the right track.
mak
pk.

Thank for reading my post. Y es i did clean the icv with crb cleaner . my old icv was good but i just got another one frm ebay to see if this is the problem . new is clean i tested it work good. i can hear the clicking noise when i turn on the ignition to on position. but my idle goes up to around 1500 rpm then down to 5 to 600 then car stall. If i keep the foot down on the gas, car will stay on i can feel that car wants to stall , once it reached to little normal temperature then problem starting to be little less , then by it self rpm will come down to around 6 to 700 rpm . i was reading other people post saying this can cause by bad eha, ovp , and also i should be getting around 7to 8 volts at icv when car is running , i test my it is getting around 12 volts is this can cause problem to much volts and how i can fix this to proper volts . thank a million for all who help in this matter.

M. Sheikh.

To me, it sounds very much like a possible throttle switch failure. It lies underneath your fuel distributor/air flow assembly. Consists of a butterfly valve, throttle body, with an electric switch integrated as well.

Commonly reffered to as a TPS (Throttle Position Switch) on other cars. I know that on a 300E engine in good tune, unplugging the throttle switch will cause the idle to go up from 500 to 900rpms. If the switch fails in the WOT position, it will tell your ECU to fuel for WOT (Full Acceleration Enrichment), even at IDLE!

Good luck,

there is a mass airflow sensor actually, its the 3 pin connector on the air duct that attaches to the air filter housing.

does the automatic tranny perform brake ****s intermittenly or not at all? why are words censored on here? wasnt a swear?

You may have a problem with your rubber seals with your injectors

Thank u john and oracle for you are input on these issue i will check for TPS, and can anybody please highlight how to test TPS that will be hepl full to me. talking about mass air flow sensor, one side of the fuel distributor is EHA and other side is MAS please explain how to test this dvice . I am also getting check engine light on reading code 4 which is link to MAS, i did erased code but it come back after couple of minutes.