Cold start valve: Testing question

Nov 3, 2008 | 05:00 PM

Ron in SC

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From: Charleston, SC

99 ML 320, 97 Porsche 993 C2S, 92 300E

Cold start valve: Testing question

Can the cold start valve be tested when it's not installed in car?

I know it is getting voltage when engine is cranked, since I tested the connector.

I supplied voltage to CSV when it was out of car since I thought I might hear it click or something. I heard nothing.

Any suggestions?

Nov 3, 2008 | 09:51 PM

RBYCC

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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

Quote:

Originally Posted by Ron in SC

Ambient temp in SC hasn't been low enough for the CSV to come into the starting circuit.

Put it in your refrigerator and get it down to about 40F.
You should get voltage through it, but it only functions for a short time in order to start under a cold ambient.

Nov 4, 2008 | 07:32 AM

Ron in SC

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From: Charleston, SC

99 ML 320, 97 Porsche 993 C2S, 92 300E

[QUOTE=RBYCC;3147876]Ambient temp in SC hasn't been low enough for the CSV to come into the starting circuit.QUOTE]

Ok, that makes sense.

I'm trying to diagnosis a very hard to start situation. I've ruled out all the sensors in the head.

I'm trying to test the ISV, I put meter to connector and cranked engine. No voltage to connector. Maybe that is the problem.

Edited:

I just tested the ICV and when I supply 12 volts to it I hear it working.

Problem is that when I crank starter I do not getting any voltage going to ICV connector.

I have tested all sensor in the head and they are within ohm specs for a cold engine.

When I test connector wires with ohm meter I get 157K ohms.

So what next? Do I have a broken wire somewhere?

Last edited by Ron in SC; Nov 4, 2008 at 08:10 AM.

Nov 4, 2008 | 08:53 AM

RBYCC

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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

[QUOTE=Ron in SC;3148322]

Quote:

Originally Posted by RBYCC

Ambient temp in SC hasn't been low enough for the CSV to come into the starting circuit.QUOTE]

Ok, that makes sense.

I'm trying to diagnosis a very hard to start situation. I've ruled out all the sensors in the head.

I'm trying to test the ISV, I put meter to connector and cranked engine. No voltage to connector. Maybe that is the problem.

Edited:

I just tested the ICV and when I supply 12 volts to it I hear it working.

Problem is that when I crank starter I do not getting any voltage going to ICV connector.

I have tested all sensor in the head and they are within ohm specs for a cold engine.

When I test connector wires with ohm meter I get 157K ohms.

So what next? Do I have a broken wire somewhere?

Have you looked at the OVP and fuel pump relays?

The OVP is a major junction point for the signals that will start the engine.
Could be something as simple as a blown OVP fuse or a weak relay.

Nov 4, 2008 | 09:10 AM

Ron in SC

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From: Charleston, SC

99 ML 320, 97 Porsche 993 C2S, 92 300E

[QUOTE=RBYCC;3148374]

Quote:

Originally Posted by Ron in SC

Have you looked at the OVP and fuel pump relays?

The OVP is a major junction point for the signals that will start the engine.
Could be something as simple as a blown OVP fuse or a weak relay.

I had previouly swapped out the MAS relay and the OVP from my other 1992 300. No difference.

Shouldn't I be getting power to the ICV when I crank the engine?

Nov 4, 2008 | 01:54 PM

RBYCC

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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

[QUOTE=Ron in SC;3148393]

Quote:

Originally Posted by RBYCC

I had previouly swapped out the MAS relay and the OVP from my other 1992 300. No difference.

Shouldn't I be getting power to the ICV when I crank the engine?

ICV = Idle control valve ?

M103-12V or M104-24V engine ?

M103 uses an idle control valve with the KE injection, I don't believe M104 with the HFM injection has an idle control but uses an electronic throttle actuator.