Author Topic: Cold Start Valve  (Read 4218 times)

glcg123

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Cold Start Valve
« on: May 14, 2014, 02:15:05 »
My 230SL is not starting that well when cold. This is  a new problem. I have put on a bulb tester and notice that the CSV solenoid is activated for a couple of seconds, which is what it is supposed to do. If it does not start and you turn the key off and then on again will the CSV be activated again? If so mine does not. What could be the problem?

George

1965 230SL
« Last Edit: May 15, 2014, 13:06:25 by 280SL71 »

ctaylor738

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Re: Cold Star Valve
« Reply #1 on: May 14, 2014, 13:41:30 »
The only way to really test the valve is to take it out, reconnect it, put a plastic bag around it, and see if it sprays when you crank the starter.

It's possible that there is not enough voltage to open the valve.  Suggest you test with a meter.

When attempting a re-start, there might or might not be current to the valve, depending on whether the the thermo time switch opened during the first starting try.

Cheers,

CT
Chuck Taylor
1970 280SL #13027 (restored)
1966 230SL #15274 (sold)
1970 280SL #14076 (sold)
Falls Church VA

glcg123

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Re: Cold Start Valve
« Reply #2 on: May 14, 2014, 14:30:20 »
I will pull it and check the spray. How long of a delay is needed before the thermo switch allows it to cycle again?

George

ctaylor738

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Re: Cold Star Valve
« Reply #3 on: May 14, 2014, 15:37:52 »
Dunno.  It would depend on the temperature and how long you cranked the engine the first time.

But, after thinking for a minute, you have a 230, so you should get a one-second shot from the valve regardless.  Sounds like your hot start relay/timer isn't working.

Cheers
Chuck Taylor
1970 280SL #13027 (restored)
1966 230SL #15274 (sold)
1970 280SL #14076 (sold)
Falls Church VA

zalsaigh

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Re: Cold Star Valve
« Reply #4 on: May 14, 2014, 21:56:29 »
I would agree with the others, that your CSV nozzles are clogged. You may test them by taking the three Allen screws out and disengage the air line from the CSV, then pry the whole CSV out, let someone crank the engine and observe if the 2 jets are spraying properly. If not, you need to dismantle the CSV and force the jet head out by players and try to clean them. They are tough to clean though. I used an acid to get them open. Try regular coke which has a weak acid, if not try a diluted battery acid and see which one do the job. Good luck.
Alchemist
10 ML350
04 Crossfire/SLK
91 300SE
74 280SL
72 250C
67 230SL

ja17

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Re: Cold Start Valve
« Reply #5 on: May 15, 2014, 14:32:00 »
Hello George,

Also check to make sure that the injection pump solenoid is activating any time the starter is engaged.
Joe Alexander
Blacklick, Ohio
1969 Dark Olive 280SL
2002 ML55 AMG (tow vehicle)
2002 SLK32 AMG (350 hp)
1963 404 Mercedes Unimog (Swedish Army)
1989 flu419 Mercedes Unimog (US Army)
1998 E430
1974 450SLC Rally
1965 220SE Finback

glcg123

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Re: Cold Start Valve
« Reply #6 on: May 16, 2014, 02:11:16 »
I checked the electrical and everything seems fine. How do I remove the jets? Can they be unscrewed? They appear to be fed by a small hole in a tube that runs horizontally.

George

ja17

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Re: Cold Start Valve
« Reply #7 on: May 16, 2014, 06:44:25 »
George, you have two starting solenoids on your engine. One on the intake and the other on the IP.  Did you check them both?
Joe Alexander
Blacklick, Ohio
1969 Dark Olive 280SL
2002 ML55 AMG (tow vehicle)
2002 SLK32 AMG (350 hp)
1963 404 Mercedes Unimog (Swedish Army)
1989 flu419 Mercedes Unimog (US Army)
1998 E430
1974 450SLC Rally
1965 220SE Finback

glcg123

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Re: Cold Start Valve
« Reply #8 on: May 16, 2014, 14:34:53 »
I checked them both with my tester lead to the ground of the battery. They are both OK. I just checked the starting valve with the ground of the tester onto the battery, and not the ground wire location on the fender. It fires for 1 second like it is supposed to. I think my problem is a bad ground to the solenoid. I will clean up the ground wire area and see.

George

glcg123

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Re: Cold Start Valve
« Reply #9 on: May 18, 2014, 15:42:01 »
I finally solved the poor cold start problem. It was a bad ground to the solenoid. That said I had the valve apart and tried to clean the nozzles. Do they come out of the assembly? There is a small hole on a barrel on the inside of the valve that goes to the nozzles. I tried to squirt some carb cleaner in there but it is quite tight to do. It would be much easier to have the barrel and nozzle assembly out.

George 230SL

zalsaigh

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Re: Cold Start Valve
« Reply #10 on: May 21, 2014, 03:32:03 »
George, The nozzles on the CSV can come apart by using a pliers, wiggle the nozzle assemble out of its seat. Use a rag to protect the nozzle from the pliers and always mark which side which before removing. I had a tremendous difficulty to a point I used a battery acid for a short time, then rinse them with water. Protect your skin from the acid by wearing plastic gloves and wear goggles. Good Luck.
Alchemist
10 ML350
04 Crossfire/SLK
91 300SE
74 280SL
72 250C
67 230SL