Question about 1990 Mercedes-Benz 190

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190e engine idling sometimes engine turn off

Please help! 190e engine idling sometimes engine turn off A couple of years has driven without air controller not connected (IAC) was set on the screws manualy I recently changed the airflow potentiometer. And now the cold start 1-2minute 1100 rpm and drop to 750rpm sometimes goes off when the engine idling. My question is why ?? instructions LMM POTI (air flow potentiometar) Engine idling ________________________________________________ PIN ________________________________________________ 1,2 : 0.75 V +- 0.20 V ________________________________________________ 1,3 : 4.85 V +- 0.25 V ________________________________________________ Engine off _________________________________________________ disconnected connector PIN: 1,3 4Kohma +- 400 ohma

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SOURCE: Radiator coolant

first question is after you changed your hose and refilled while the car was running with the radiator cap locked but loose with the heater on high and set on hot run the car till the thermostat opens shut the car down once it does anti freeze level will drop and air will rise and (extreme caution taken with drain pan below ) start the car use two people run it shut it down let air escape threw cap start again run a couple of minutes shutdown again let cool down take cap off restart car with cap off watch radiator level will somone lightly increases gas peddle refill level to top reinstall cap completely tight then let idle down some vehicles have a small bleeder mounted in the thermostat houseing or in line with the radiator circulation system

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cold start valve malfunctioning
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SOURCE: Delay reaction of cold start and idle

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SOURCE: mercedes benz 190e 1900year /air flow meter connections

Guys i just bought my first car and its a Mercedes 190E 1.8L 1991. Now i noticed an digital meter just above my steering wheel with 2 knobs on each end. I dont know what is it for can u tell me plzz. Thanks :>

Posted on Jul 13, 2009

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SOURCE: while in park 1988 mercedez benz 190e idles rough and sometimes

This is an interesting part, and I spent quite some time to fix the problem. I list it here those steps in the order could fix the problem ranging from least expensive to most expensive steps. It just happened to me the last one really eliminated the problem. 1- Make sure it gets turned up first. 2- Adjust cables to increase idle. There are two cables. You remove the air filter to see them clearly. a- one for the gas, the other for transmission. b- clean the area well so you can see a micro switch. This switch called cut off switch. c- whatever adjustment you make, the level of the switch has to press on the switch to maintain the idle. If you see it off, you can bend the metal part to keep it in place 3- Take off the Fuel distributor to clean the throttle below it. 4- Replace all the injectors. These are not Electronic Fuel Injectors so you don't have to deal with Injector module. 5- Replace the fuel distributors. Good luck.

Posted on Sep 26, 2009

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How do I adjust idle on 2009 Toyota Corolla 1.8 liter


There are no provisions for adjusting the idle . The computer through the use of the IAC valve - idle air control controls the idle . There is a base idle set at the factory an should not be changed or messed with . What idle problem are you having ? low or high Could be IAC valve or air passages plugged . High idle the throttle plate could be gummed up an sticking ! If you were to change the base idle you cause check engine light problems .
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What is an IAC Valve


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  • Idle air control actuator - Wikipedia, the free encyclopedia https://en.wikipedia.org/wiki/Idle_air_control_actuator An idle air control actuator or idle air control valve (IAC actuator/valve) ... Idle air control actuator; MAP sensor; Mass flow sensor; Oxygen sensor; Starter motor;
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    May 12, 2016 | 1992 Toyota Paseo

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    How to fix fault code P1507


    Possible causes
    - Faulty Idle Air Control (IAC) valve
    - Idle Air Control (IAC) valve harness is open or shorted
    - Idle Air Control (IAC) valve circuit poor electrical connection
    What does this mean? Tech notes
    The P1507 code means that the engine idle is out of factory specification. Sometimes the Idle Air Control (IAC) may have carbon built up. Disconnect the car battery, remove the valve, clean, re-install valve, and drive the vehicle for about 5 minutes with the headlights and A/C ON to get the idle relearned.
    If the problem persist, the IAC valve may need to be replaced.

    Read more: http://www.engine-codes.com/p1507_ford.html#ixzz3sFPyZe00

    Nov 22, 2015 | 2000 Ford Ranger SuperCab

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    190e engine idling sometimes engine turn off


    Hello My Fixya Friend, Such things happen in winter seasons. Still if you have any doubts just visit the link I provide to you. They will guide you properly that what has happen to your car, and they will give you the solution for the same. Best Manuals

    Mar 17, 2017 | 1990 Mercedes-Benz 190

    1 Answer

    Just started idling rough, sometimes stalling


    Shot in the dark here without knowing the vehicle but it could be an Idle Air Control valve starting to fail. An IAC (idle air control) motor is designed to adjust the engine idle RPM speed by opening and closing an air bypass passage inside the throttle body. The cars computer or PCM (powertrain control module) receives information from various sensors and will output signals to adjust the idle air control motor in or out to adjust engine idle speed by controlling engine idle air. An idle air control motor can fail one of two ways, either the motor short circuits and stops working or the motor will develop high resistance and cause the idle air control motor to react slowly, either failure can cause the engine to stall at idle. When a trouble code scan is performed it sometimes won't always detect a failed or weak idle air control motor. To check the idle air control motor remove the unit, with the wires connected turn the key to the "on" position without starting the engine, the idle air control should move in or out. If the idle air control motor does nothing it has probably failed, replace it with a new unit and recheck system. Note: while the idle air control motor is removed clean (use aerosol carburetor cleaner) the passages the idle air control uses to control idle air speed, also inspect the idle air control for a build-up on the seating (pointed) end and clean as necessary.

    Jul 20, 2011 | Mazda B2300 Cars & Trucks

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    Will not idle, will run if you push on the gas and hold it. No engine light indicator


    you need to clean your idle air control valve ( or replace it) Spray carb cleaner does a nice job of cleaning it.

    This tutorial is from autozone.com


    OPERATION



    The Idle Air Control (IAC) is a bi-directional motor driven by two coils. The purpose of the IAC valve is to control engine idle speed, while preventing stalls due to changes in the engine load. The IAC valve, mounted in the throttle body, controls bypass air around the throttle plate. The PCM controls engine idle speed by adjusting the position of the IAC motor pintle. The PCM pulses current to the IAC coils in small steps (counts) to extend the pintle into a passage in the throttle body to decrease air flow. The PCM reverses the current pulses to retract the pintle, increasing air flow. This method allows highly accurate control of idle speed and quick response to changes in engine load. If RPM is too low, the PCM will retract the IAC pintle, resulting in more air being bypassed around the throttle plate to increase RPM. If the RPM is too high, the PCM will extend the IAC pintle, allowing less air to be bypassed around the throttle plate, decreasing RPM.



    0900c15280217cd2.jpg enlarge_icon.gifenlarge_tooltip.gif

    Fig. Typical Idle Air Control (IAC) valve components
    During idle, the proper position of the of the IAC pintle is calculated by the PCM based on the battery voltage, coolant temperature, engine load and engine RPM. If the RPM drops below a specified value, and the throttle plate is closed (TP sensor voltage is between 0.20-0.74), the PCM senses a near stall condition. The PCM will then calculate a new IAC pintle position to prevent stalls.
    If the IAC valve is disconnected and reconnected with the engine running, the idle RPM will be wrong. In this case, the IAC has to be reset. The IAC resets when the ignition switch is cycled ON and then OFF . When servicing the IAC, it should be disconnected or connected with the ignition switch OFF in order to keep from having to reset the IAC valve.
    The position of the IAC pintle affects engine start up and the idle characteristics of the vehicle. If the IAC pintle is fully open, too much air will be allowed into the manifold. This results in high idle speed, along with possible hard starting and a lean air/fuel ratio. A Diagnostic Trouble Code (DTC) may set. If the IAC pintle is stuck closed, too little air will be allowed in the manifold. This results in a low idle speed, along with hard starting and a rich air/fuel ratio. Again, a Diagnostic Trouble Code (DTC) may set. If the IAC pintle is stuck part way open, the idle may be high or low and will not respond to changes in engine load.


    TESTING



    As with most all engine control sensors used in your vehicle, a thorough and proper test can only be performed by a qualified technician using a scan tool to read the data stream from the PCM. There are a few items a non-professional should check before taking the vehicle to a qualified technician for diagnosis and repair.



    Check for a poor connection at the PCM or IAC motor. Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals and poor terminal-to-wire connection. Inspect for a damaged wiring harness, especially if heavy work has recently been performed (intake manifold removal, engine removal, etc.) where the throttle body has been disturbed. Inspect for a restricted air intake system. Check for a possible collapsed air intake duct, restricted air filter element or foreign objects blocking the air intake system. Inspect the throttle body. Check for objects blocking the IAC passage or throttle bore. Excessive deposits, especially on high-mileage engines, can build up in the IAC passage and on the IAC pintle. Excessive deposits can also build up on the throttle plate, so check for a sticking throttle plate. Check for vacuum leaks such as disconnected hoses, leaks at the EGR valve and EGR pipe to the intake manifold, leaks at the throttle body, faulty or incorrectly installed PCV valve, leaks at the intake manifold brake booster hose connection, etc.



    REMOVAL & INSTALLATION



    1. Disconnect the negative battery cable.
    2. Detach the electrical connector from the IAC valve.
    3. Remove the 2 attaching screws and remove the IAC valve from the engine. Remove the O-ring from the housing.

    To install:



    0900c15280217cd3.jpg enlarge_icon.gifenlarge_tooltip.gif

    Fig. The Idle Air Control (IAC) valve is mounted on the throttle body-3.8L (VIN K) engine shown, others similar


    NOTE Before installing a new IAC valve, measure the distance that the valve is extended. The measurement should be made from the motor housing to the end of the valve cone (pintle). The distance should be no greater than 1 1 / 8 inch (28mm). If the pintle is extended too far, adjustment is required, otherwise damage may occur when the IAC valve is installed. Adjust the IAC valve by compressing the pintle to achieve the correct length.


    1. Use a new O-ring, install the IAC valve and tighten the retaining screws to 18 inch lbs. (2 Nm).
    2. Attach the electrical connector.
    3. Connect the negative battery cable.
    4. The PCM will reset the IAC valve the next time the ignition switch is turned ON and then OFF .
    5. Start the engine and allow to warm to operating temperature to check idle quality.

    Oct 13, 2010 | 2000 Pontiac Grand Prix

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    1990 4Runner, 3.0 L engine, won't hold idle, wants to stall, no power. Replaced Mass air flow valve sensor, replaced fuel pump, distributor cap and rotor, plugs. It has good fuel flow but only runs well...


    Have you looked at your idle air control valve What is it? This is an electrically driven valve that allows additional control over the throttle at idle Where is it located? The IAC is located on or adjacent to the throttle body and consists of a small device held on by two bolts with an electrical connector.
    How does it work? When the throttle is closed the throttle plate closes off any air from the intake manifold. In order to stop the engine from stalling due to lack of air the IAC opens a small valve allowing air to pass from the air ducting to the intake manifold. Often the IAC components consist of an air inlet port in the inside wall of the throttle body, immediately in front of the throttle plate, with a similar exit port behind the throttle plate. Connecting the two ports is a motor driven valve. When the valve is opened air effectively by-passes the closed throttle plate to maintain the engine at idle. The IAC also augments the throttle when additional power demands are put on the engine such as steering.


    Symptoms of faulty IAC

    • Poor starting: If the IAC fails to open or the inlet/exit ports are clogged shut with carbon the engine may start and then promptly stall. The engine can be kept running by pressing the accelerator. However any additional demand on the engine such as power steering or putting the car into drive (automatic) will cause the engine to stumble badly and often stall.
    • Engine cut out: Even with the engine warmed when the vehicle is stationary such as at a red light the putting of the transmission into of 'drive' to pull away before the accelerator is pressed can cause the engine to stall. (Note this differs from the TPS fault which causes engine stall due to the accelerator being pressed too quickly)

    How to check? Physically remove the IAC but keep the electrical connection to it. Temporarily block off the now open ports on the throttle, turn the engine on and examine the IAC valve action in response to additional loads (power steering inputs etc). The valve should open and close according to demand.

    How to fix? If the motor of the IAC has failed then replace the IAC. If the valve is gummed closed by baked oil and carbon then clean it thoroughly with carburetor choke cleaner spray and a cloth. Similarly if the entry and exit ports on the throttle body to the IAC look blocked again clean them out thoroughly.

    Jun 03, 2010 | 1990 Toyota 4Runner

    1 Answer

    Wont start when warm without pumpin gas, and engine revving to high


    A high rev problem is due to either carbon build up in the iac passage's not letting the iac close to normal idle or the iac is just bad and stuck in that position.

    iac= idle air control solenoid

    Inside the throttle body intake is a butterfly and just above that is a small opening that the iac uses to move air past the butterfly and this sometimes gets plugged with carbon build up so spray some carb cleaner down through the passage,and sometimes you have to remove the 4 bolts and take the throttle body off to clean them out.

    Saturns are known for carbon problems,and they are hard on egr systems,I recommend using sea foam a couple times a year to help fight the carbon build up,just follow the direction and use it in the fuel and vaccum lines as directed but do it on a warm engine and let sit for a couple hours so the sea foam has time to loosen the carbon

    May 31, 2010 | 2005 Saturn SC1

    1 Answer

    Idle is too low, car dies, engine runs fine


    An IAC (idle air control) motor is designed to adjust the engine idle RPM speed by opening and closing an air bypass passage inside the throttle body. The car computer or ECM (electronic control module) receives information from various sensors and will output signals to adjust the IAC motor in or out to adjust engine idle speed by controlling engine idle air.
    An IAC motor is highly susceptible to carbon and coking build up; if an IAC goes too long without cleaning it can cause stalling and poor idle quality. Some cars are designed with a large vacuum transfer hose that connects the intake manifold to the IAC (idle air control) motor. If a broken or dilapidated these vacuum lines can cause the engine to lose vacuum which will allow the engine to run rough and die. 
    Inspect all engine and accessory vacuum lines to look for missing, torn or dilapidated lines and replace as needed. To check the IAC motor remove the unit, with the wires connected turn the key to the "on" position without starting the engine, the IAC should move in or out. 
    If the IAC motor does nothing it has probably failed, replace it with a new unit and recheck system. Note: while the IAC motor is removed clean (use aerosol carburetor cleaner) the passages the IAC uses to control idle air speed.

    Good luck and hope this helps

    May 08, 2009 | Honda CR-V Cars & Trucks

    1 Answer

    Car idle


    battery and iac sensor cause this problem....... check battery conections and replace the idle air control valve on the intake....

    Oct 14, 2008 | 2000 Jeep Grand Cherokee

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