Author Topic: Manual activation of CSV  (Read 1462 times)

FresnoBob

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Manual activation of CSV
« on: July 26, 2019, 15:58:53 »
I installed a momentary switch to active my CSV in an attempt to make the car start better.  Does anyone have any advice or experience as to how this works best?  I've tried a short blast before or after engaging the starter, but nothing seems optimal yet.  I did clean the nozzles and they spray a fine mist now.  The car also dies immediately if I activate the CSV while idling. 
Bob Comstock
1966 230 SL Euro Auto
2017 AMG C43 Cabriolet

teahead

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Re: Manual activation of CSV
« Reply #1 on: July 26, 2019, 16:22:21 »
does it leak?

Dying while idling, surely will happen with more fuel.
1970 280SL auto, AC - aka "Edelweiss"

FresnoBob

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Re: Manual activation of CSV
« Reply #2 on: July 26, 2019, 16:44:50 »
I don't believe it leaks.  The car idles smoothly with A/F ratio of 12.8 - 13.1.

I was only testing the operation by activating the CSV while idling. 

My one second relay isn't functioning, yet. 
Bob Comstock
1966 230 SL Euro Auto
2017 AMG C43 Cabriolet

Tomnistuff

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Re: Manual activation of CSV
« Reply #3 on: July 27, 2019, 00:13:00 »
After working for about a month to make the Cold Start System work as it was intended to, I decided to do as my mother would have said to do and that is give it a "lick and a promise", then quit working on it.  That is a lick now (Missouri slang for attempt) and a promise to do better later.

I disconnected all the cold start devices except the WRD (it's not electric anyway), and added a push-on/release-off button beside the driver's left knee for the Cold Start Solenoid.

Mine works fine by opening the CSV simultaneously with the commencement of starter operation and release it a couple of seconds after it starts firing.  That's usually about five seconds in the summertime after an overnight ambient temperature "soak".  That's a term used by the U.S. auto industry, meaning an untouched temperature cool-down and stabilization period.

So far, mine has worked fine with that technique.  When I experimented with pre-crank CSV, starts got worse.  If I shut it off before it fires, then it doesn't fire at all.  I'll stay with the technique that simulates the original automatic system with a guess for injection duration.

Eventually, I'll probably create a Cold Start System Overlay Electrical Harness to patch in to the original.  If it works, then I'll go back to the original automatic cold start system.  All the devices seem to diagnose correctly except they don't work when they are connected into the original harness.  I think there's a short somewhere that blows #6 fuse at start of crank.  That's really why I bypassed and disconnected all the fuse #6 components, removed the fuse and wired the bypass switch outside the fuse system with heavy duty switch and wires.  The CSV only used 3.1 or 3.2 amps anyway.

Good Luck

Tom Kizer
Apparently late 1966 230SL 4-spd manual (Italian Version)
Owned since 1987 and wrapping up a full rotisserie restoration/modernization.
Was: Papyrus White 717G with Turquoise MBtex 112 and Kinderseat
Is: Dark Blue 332G with Dark Blue Leather (5300, I think)

wwheeler

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Re: Manual activation of CSV
« Reply #4 on: July 27, 2019, 00:28:14 »
I installed a momentary switch on the CSV and was told it is common practice. That was one of the best things I have ever done. I wired mine so that the CSV system still functions automatically though. I did disconnect the starting solenoid as I found it flooded my engine when starting hot and with a CSV switch, it is unnecessary. If you are using a CSV manual switch, I would recommend you disconnect your starting solenoid wire.

I only use the CSV manual switch before the engine cranks. When cold, I give it a second or two blast and the engine starts within a second. The theory here is that activating the CSV before the engine starts, fills the intake with fuel and gets sucked in the moment the engine starts turning over. I also use a half throttle to make sure there is enough turbulence in the manifold to suck in air and fuel.

I never use the CSV when hot or warm. I created a log for my engine and using that, determined the best times to use the switch. Took me about 6 months to document all of the different scenarios.

Good luck
     
Wallace
Texas
'68 280SE W111 coupe
'60 220SE W128 coupe
'70 Plymouth Roadrunner 440+6

rgafitanu@gmail.com

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Re: Manual activation of CSV
« Reply #5 on: July 29, 2019, 17:47:57 »
I have the same setup as Wallace above. I give it 5-6 seconds during the winter and 0-2 seconds now. No CSV when engine warm or hot. I didn't disconnect the starting solenoid though. Maybe I should try that to improve the hot start that appears to require WOT.

FresnoBob

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Re: Manual activation of CSV
« Reply #6 on: July 29, 2019, 21:37:58 »
Thanks everyone for your experiences and thoughts.  I'll continue to experiment and I'm taking my car to 7,000 ft this weekend, where it will start cold in the morning.  Hope to meet many of you at the PagodaFest. 
Bob Comstock
1966 230 SL Euro Auto
2017 AMG C43 Cabriolet

wwheeler

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Re: Manual activation of CSV
« Reply #7 on: July 30, 2019, 15:47:53 »
Radu,

I did indeed find that the starting solenoid was flooding my engine when hot. The difference with it disconnected was staggering. You do however have to compensate for it when cold via the manual switch. They did do away with the starting solenoid on the final iteration of the pump afterall. 

Since I installed that CSV switch, I have never flooded the engine or has ever taken more than a couple of seconds to start. For me, the two variables are just the cold start switch and opening the throttle 1/2 way all depending on engine temperature. 
Wallace
Texas
'68 280SE W111 coupe
'60 220SE W128 coupe
'70 Plymouth Roadrunner 440+6