My dear friend, I have been driving a MERCEDES 190E 2.3 for the past 3 months now. When I start the car, it doesn't ignite immediately. The batteries are new, the sparkplugs are new and the mechanic says the valve works fine. I'm really baffled. I would look at the manual but I don't have one.My question is - is there a special way to start the car (eg pump gas pedal, turn key slowly.) Is it because of the cold weather. I would greatly appreciate it if someone can help me. Thank You. Oh and EVERYONE HERE ROCKS!!! THANKS AGAIN!!!

If you do not smell gas, then likely your system is too lean to start when cold. If it seems to run normally warm, and gas mileage isn't bad, then I would check temperature sensors and cold-start enrichment components. Details in that department would require info on the year and country/state of origin of your 190E.

Steve

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'91 MB 190E 2.3
'08 RAV4 Ltd 3.5
'83 Lazy Daze m'home 5.7

This info is applicable to 190Es with the 4 pin coolant temp sensor (like mine) :

The engine coolant temp sensor provides feedback to the ECU.

The ECU richens the mixture on a cold engine to assist startup.

If it's screwed (no pun intended), you will have difficulty starting coz the mixture will be too lean.

To test the sensor, pull the connector off and use a multimeter (set to test resistance) on the diagonally opposite pins.

You should approximately get the following resistance values corresponding to the temp just for your info :

6000 ohm - 0deg Celcius
3000 ohm - 20deg C
1300 ohm - 40deg
600 ohm - 60deg
300 ohm - 80deg
200ohm - 100deg

The pin assignments are :

1 Distributor ignition temp sensor
2 CFI temp sensor
3 Engine ground at intake manifold for distributor ignition system
4 CFI control module ground

At this point in time, you should check the resistance since the engine doesn't start and is cold. You should get a value "big" value corresponding to the ambient temp in your area.

Mine checks out at around 2000 ohms and it's very warm/humid where I live (around 30deg).

It's a cheap and easy replacement - around 20 bucks.

You just unscrew the old one out with an adjustable wrench and screw the new one in.

Good luck.

The connector for the engine coolant temp sensor is circled in the photo.

Just pull off the connector from the top and you can see the sensor (which is screwed in to the engine.

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Hi Newmecedesguy, did you sort out your cold start problem and was it the temperature sensor or something else. i have the same problem but on a C180.

Hi Azari, what tools do I nee to measure the Ohm on the temp sensor, I have simple multimeter with ohms x10 and Ohms x1K switch, is this good enough or do I need something special? also how do I measure the ohms - just attached the red and black pin of the meter to the 2 temp sensor pins?


Thx

I put a new battery into my multimeter and checked the resisitence through the temp sensor - it reads 5000 Ohms cold and 20 ohms hot; so is working. I reckon its something else.

Could it be the throttle body?

The mer deasler wants £150 GBP for 1 hours of diagnostic!! Sounds pricy; so looking for a solution in the mean time.

Thx