Hard Cold Start
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w124 e280 1994
Hard Cold Start
When I start my Car cant idle until when it warn. So I have to step the gas until when the temperature needle nudges to around 40 then I can let go of the pedal. Otherwise it shuts down. Recently changed plugs and fuel filter. What could the issue be?
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From: Bellevue, NE
1995 E320 SE, 162,000 Miles (Sold) 2007 CLK350 Cabriolet 2014 ML550
I nominate the idle control valve. The cold start should not be active when the key is released from the start position, right?
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From: REHOBOTH BEACH DE
88-300CE TWIN TURBO, 99-C43, 05-G55K, 71-280SL, 94-E320 CAB, 08 CLK63 BLACK SERIES
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From: Connecticut, New Haven
95' AMG SeeThreeSix
The cold start valve is powered by the fuel pump relay. From the diagram it does look like the coil wire in the fuel pump relay is activated by the ignition switch at position 3 upon starting. Thus the Cold start valve seems to be actuated upon starting action only (when starter motor is actuated). Idle control valve may be the legitimate gremlin in this case?
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From: REHOBOTH BEACH DE
88-300CE TWIN TURBO, 99-C43, 05-G55K, 71-280SL, 94-E320 CAB, 08 CLK63 BLACK SERIES
The cold start valve is powered by the fuel pump relay. From the diagram it does look like the coil wire in the fuel pump relay is activated by the ignition switch at position 3 upon starting. Thus the Cold start valve seems to be actuated upon starting action only (when starter motor is actuated). Idle control valve may be the legitimate gremlin in this case?
The cold start valve gives about an 8 second shot depending on ambient temperature.
Acts like a choke in a carburetor.
Enrichens enough to stabilize idle until the temp warms up.
I reread the OP and noticed the vehicle is a 1995 which would have HFM injection.
HFM doesn't have the cold start or idle control that is used on the CIS-E.
It has a mass air flow sensor
HFM is fully electronic.
My comments were to the CIS-E
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From: Connecticut, New Haven
95' AMG SeeThreeSix
ahhhhh see what happens when I think everyone rolls in a 86' 300E!!! haha, while on the subject however would my assumption be correct pertaining to a CIS-E injection like mine, or there is a 8 second timer? Where is this in the schematic or is it a signal sent from the KE control unit?
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MBWorld Fanatic!
Joined: Dec 2006
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From: Bellevue, NE
1995 E320 SE, 162,000 Miles (Sold) 2007 CLK350 Cabriolet 2014 ML550
The cold start valve gives about an 8 second shot depending on ambient temperature.
Acts like a choke in a carburetor.
Enrichens enough to stabilize idle until the temp warms up.
I reread the OP and noticed the vehicle is a 1995 which would have HFM injection.
HFM doesn't have the cold start or idle control that is used on the CIS-E.
It has a mass air flow sensor
HFM is fully electronic.
My comments were to the CIS-E
Acts like a choke in a carburetor.
Enrichens enough to stabilize idle until the temp warms up.
I reread the OP and noticed the vehicle is a 1995 which would have HFM injection.
HFM doesn't have the cold start or idle control that is used on the CIS-E.
It has a mass air flow sensor
HFM is fully electronic.
My comments were to the CIS-E
but with HFM, what do you think about the Temp Sensor? I'm thinking it could give a false reading and make the controls think the engine is already partially warmed up.
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From: Long Beach, Ca
lots of cars
I would think it would be easier to find out what's the problem with his car because he could check for codes. That's the first thing I would do..
Hey I roll in an 86 300e <<<---- LOOK..lol....There aren't many of us left....
If he has a m103 engine It should be the CIS Temp Sensor at the rear of the engine. If he has a m104 then i really have no idea where this would be...
On mine i have 2 temp sensors the green one in the middle of the engine but the important one is the one at the rear with the two posts on it. That's the one that controls how rich or how lean it is on starts.
Hey I roll in an 86 300e <<<---- LOOK..lol....There aren't many of us left....
If he has a m103 engine It should be the CIS Temp Sensor at the rear of the engine. If he has a m104 then i really have no idea where this would be...
On mine i have 2 temp sensors the green one in the middle of the engine but the important one is the one at the rear with the two posts on it. That's the one that controls how rich or how lean it is on starts.
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From: Connecticut, New Haven
95' AMG SeeThreeSix
not to steal the thread but where is this sensor in the rear that conrols mixture upon startup? I have a cold start issue and am trying to compile a list of things to replace and ive never heard of this sensor
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From: Long Beach, Ca
lots of cars
This tells the computer when the car is cold or hot and controls the idle speed. If your car idles around 800-900 when it's cold then it means it's working. If your car only wants to start when it's warm then it means this is not working. The green temp sensor is for the aux fan and the temp gauge and has nothing to do with the cold start part of it.
Last edited by YNVDIZW124; Nov 8, 2007 at 02:27 AM.
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From: REHOBOTH BEACH DE
88-300CE TWIN TURBO, 99-C43, 05-G55K, 71-280SL, 94-E320 CAB, 08 CLK63 BLACK SERIES
ahhhhh see what happens when I think everyone rolls in a 86' 300E!!! haha, while on the subject however would my assumption be correct pertaining to a CIS-E injection like mine, or there is a 8 second timer? Where is this in the schematic or is it a signal sent from the KE control unit?
The temp sensor ( via KE control unit ) cuts it out once the water temp exceeds this setting.
Max time to reach this water temp is calculated by MB at around 8 seconds.
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From: Boston
is a German Tank
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w124 e280 1994
Recently Changed the Relay. Could it be at fault again? My Mechanic doesn't have the cable for these cars otherwise I would check the codes. Does anyone know where I can get the cable? I could hook it up to my laptop since I have Carsoft.
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From: Boston
is a German Tank
It doesnt hurt to look, it'll take you five minutes the most.
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w124 e280 1994
MBWorld Fanatic!
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From: Boston
is a German Tank
Jumping the car can blow the fuse, hence the OVER VOLTAGE.
