Multiple Cranking before Ignition

[benzwallah]

Not sure if this is an electrical problem or a fuel problem, but any thoughts and recommendations are welcome:

My 1965 230SL would not start this winter until I had cranked it multiple (10-20) times.  It would catch slightly, then die.  When it finally would catch, i needed to do some delicate footwork on the pedal to sustain the engine.  Vehicle would run just fine once it started.  It is garaged in an unheated space.

As the weather warmed in March I noted that it took only 5-10 cranks to get it going.  I took it to my mechanic, who diagnosed it as the "time switch" was no longer working. I believe ja17 wrote about this in the Forum on Jan 10, 2016.  The mechanic noted that during the warmer weather the engine should start fine without this switch.

The engine fired up on the first try when I took it out recently.  Looked like a good sign.  After parking for an hour, it took me about 30 or more cranks to get it started.  Just when the battery was starting to show signs of fatigue, the engine caught and I could get back to my garage.
Back in the garage, I parked and turned it off. Tried to start it again, but still needed a couple of cranks.

Do I need to replace that time switch or is something else going on that needs looking into?  Many thanks in advance for any advice.

[ja17]

You can open the time switch relay and clean it's contacts to restore it to operating condition. Give it a light spray of "electrical contact cleaner" while your in there.

[benzwallah]

Thx for good advice ja17, but the mechanic said it needed replacing and tossed it.  Is that switch entirely necessary in temperate weather conditions?

[teahead]

he tossed  your relay?

Need to also check if the CSS is working.

While cranking, have someone w/a test light to see if it's getting power.

[rwmastel]

Not sure if this is an electrical problem or a fuel problem, but any thoughts and recommendations are welcome ....

Didn't we just have a vary similar thread in the last week or so?

he tossed  your relay?

Yeah, right?!?!?  Aren't those often repairable?  And when not, aren't new ones expensive?

Need to also check if the CSS is working.

Cold Start Solenoid?
Constant Speed Solenoid?
(Both CSS?)
I'm probably confusing something.

[teahead]

Cold Start Solenoid I think what' I'm thinking.

The thing that fires the cold start injector.  Check for it turning on when cranking.

He tossed the relay and didn't bother replacing it with something???

[benzwallah]

OK, so he tossed it.  But he said it needed replacing and would be on the lookout for one.  I'm not a trained mechanic (obviously).  And yes, it was the CSS that was kaput.

Does the vehicle need one to start in any conditions?  Or just in very cold temperatures?  Can the engine do without one?

I've looked around and they are of course available, from under $100 to nearly $500. 

I'll follow your good advice, teahead and ja17.  Any other guidance on next steps?

Again, many thx to you experts. 

[Bshaunessy]

BENZWALLAH
  A recent experience with a non functioning CCS ( cold start solenoid….which is a fuel injector directly into the intake manifold ).   My 1970 280 SL was difficult to start in cool weather, more so in cold weather and even somewhat cranky to start in warm weather.
   I followed the advice within the tech manual , this site, "starting aid" I think it is called.   This led to diagnosing a failed CCS ( as a consequence of a failed TTS thermo time switch……those Germans do love their acronyms). Following the advice in the "starting aid” , I was able to : fix and get functional the CCS ( and the TTS); properly adjust everything else in the fuel delivery system.
  THE RESULT: car starts easily, regardless of outside temperature.  Car runs extremely well and is a pleasure to drive.

  THE MORAL OF THIS STORY:
(1) yes….you need a functioning CCS….regardless of your home climate
(2) follow the simple advice ( yourself….not your mechanic….) and .easy to follow tuning steps in STARTING AID, this website.  If you do, you will be rewarded with a better running car AND you will understand your car better ( bonding!!??)

Don’t mean to preach but ……

[teahead]

https://www.authenticclassics.com/RELAY-4-POLE-FOR-230SL-250SL-280SL-OTHERS-p/auth-009192.htm

Might as well get one and then test whether the CSS lights up when cranking.

[benzwallah]

Thanks for good advice and getting me onto the Starting Aid, Bshaunessy.  It's very helpful (and the 'preaching' is well taken!).  Appreciate your link teahead, and will follow up on getting ahold of a CCS. 

Holding my breath, I turned the key this morning and the engine fired up, first try!  Drove around, parked and waited.  Three cranks on re-starting, but on the 4th, I floored the accelerator and it caught, although with some backfiring.  I only note this because it's clear it can catch and function well (ambient temperature was 75F).  But I'd rather have everything in order & will report back in a few weeks on progress, if it might be helpful.

Really appreciate this amazing community. 

[rwmastel]

But I'd rather have everything in order & will report back in a few weeks on progress, if it might be helpful.

We always appreciate a "report back" to wrap up a thread.  Helps everyone in the future who has a similar problem and finds your thread.

[mistertj]

Exact same issue with my 64' 230SL. Read at https://www.sl113.org/forums/index.php?topic=36575.0
I followed most all the suggestions, twisted the fuses, checked for voltage at the fuel solenoid, etc. Took the assembly off the intake manifold, made sure that fuel was flowing to the valve, blew air through the unit, etc. Couldn't find anything. Put back together and the car started immediately. Immediate start later that day. The next day, the issue was back...so I am at a loss.

[lpeterssen]

Dear friends:

I was today passing through this thread again and realized that our culprit on this particular case are:

1. A faulty TTS

OR

2. A faulty timed 1 second relay

On a 230Sl, according to the wiring diagram, the COLD START AIDS, I mean the systems that help to start the car each time you crank it are EITHER activated every single time by the TIMED RELAY (only for 1 second) or the TTS for up to 10seconds depending on engine temperature.

Check both components outside the car by building a temporary circuit.

Best regards
Lp

[teahead]

Again, have someone hold a test light, or do the cranking, while seeing if the CSS injector lights up.


For me, one has to wait 2-3s in the RUN position before cranking before it immediately starts.

[mistertj]

Good info guys. Hooked up a 12 volt lamp this morning between the cold start relay and ground. Cranked cold engine...bulb turned on for about 1 second and then off. Successive cranking but no build illumination and no firing of engine. Waited a few minutes and engaged starter again...bulb lit for about a second. No start but the engine did fire once. So, my conclusion is that I have an issue in the cold start system. Not sure what has gone bad at this point.

[lpeterssen]

Dear misterTJ

As when the engine was cold you got a positive out it from cold start relay, definetlly your problem is either on the CSV Cold Start valve at the intake manifold or your enrichment selenoid at the FIP.

test those elements outside

[lpeterssen]

Also your Timed relay is not consistently giving a one second signal every time you crank the engine no matter if it’s cold or hot.  So that component is KAPUT.

SEE the solution I built for another customer in the section WANTED TO BUY

[mistertj]

I looked up and saw your 'solution'...very ingenious. Thank you. So, you're thinking is that the rounded can relay is not working properly. Do you know where I could find a schematic of that whole cold start circuitry. Here is the setup in my car.

OK...just found a schematic in one of my manuals.

[rwmastel]

MisterTJ,

Did you get a good understanding of the cold start system from these links provided in another thread?

Mistertj,
Here's a long thread about starting aid systems. Tons of info on how they work and how to troubleshoot.
https://www.sl113.org/forums/index.php?topic=27927.0

Also, you're a full member, so here's the tech manual entry.
https://www.sl113.org/wiki/Restricted/Engine-starting-aid-tour

[lpeterssen]

I looked up and saw your 'solution'...very ingenious. Thank you. So, you're thinking is that the rounded can relay is not working properly. Do you know where I could find a schematic of that whole cold start circuitry. Here is the setup in my car.

OK...just found a schematic in one of my manuals.

Yes the rounded can, which is the time relay is not doing its job all the time.  Better to substitute that with a freshly made electronic timed relay

[mistertj]

Reading up on the time relay delay the words seem to imply that the rounded can time relay only closes for a 1 second duration. My cold start injector relay does work for the "1 second" most all the time. But I'm looking for the time delay relay that allows fuel to be injected for a longer duration...maybe 5 to 10 seconds for a cold engine. Which relay is that?

[BobH]

Hello, the thermo time switch (TTS), number 32 in the schematic is what dictates the amount of time the cold start valve solenoid is energised, number 31

The TTS should supply a permanent ground (-ve) to the cold start relay, number 21, until either the temperature of the coolant opens the internal contacts, or the internal heater opens the contacts

You can prove if the TTS is working by connecting an earth to terminal W and then see if the car starts easier.  If it makes no difference then it could be the relay.  This may be the schematic for your car, or it may be the schematic for the earlier 230 you need.  The +ve to the TTS is fed to terminal G from the ignition switch and is only present during cranking

https://www.sl113.org/wiki/Restricted/ColorWiringDiagrams?action=download&upname=230sl_2.jpg

i would try this and then report back

Good luck

Bob

[mistertj]

Awesome! Great wiring diagram. I was using a magnifying glass to view mine.

[rwmastel]

But I'd rather have everything in order & will report back in a few weeks on progress

Benzwallah,

You're the thread starter, so I thought I'd check in and see if you have had time to troubleshoot the starting aids and find a faulty component.  Any luck?  I hope it works out for you.

[mistertj]

Not as yet. My daughter and grand daughters were in for the long holiday weekend.

This morning I wired up a 12 volt test light to replace the kluged jumper clip thing I was using. Then I was trying to figure out which relay is which? Number 31 is easy (the solenoid on the cold start valve). Numbers 33 and 34 I think are screwed into the appendage that's attached to the engine block). The thermo time switch number 32 I think is the round black can. Now not sure which of the remaining 19, 20 & 21 are which. There are three in a row after the black can but I was told that one of them is a windshield wiper relay. Anyway...making progress.

So, just hooked up my test bulb, turned the key to crank the engine. Surprise...surprise, the test bulb stayed on and the engine started. I had spun the number 6 fuse in its position when I was trying to trace continuity in trying to find the number 21 relay. That might have done it but a week ago I also spun all the fuses because it was suggested that I try that as part of other suggestions.

Well, the problem has gone away at least for now but I'd still like to determine which relay is which. Will work on that. Anyway, to everyone, thank you for the inputs.