Warm engine starting

[wwheeler]

This thread has been very enlightening to me. Interesting thought on two counts. I have noticed that when I do disconnect the start solenoid, the engine seems to crank faster. Am I crazy or is it the draw from the solenoid as mentioned. If so, it gets disconnected! I did not know about the shaft wear and yet another reason to disconnect if not needed.

I was going to hook the CSV manual switch up to a keyed power source (not start circuit) and can do so easily because my W111 has power windows. That source is very close to the CSV. With my first crude test, I did notice that firing the CSV before the engine cranks yields better results. I first turned on the fuel pump, ran over and jumped the solenoid, then ran back and stared the engine. The manual switch will be easier but I won't get as much exercise

I am adding this CSV switch tomorrow and will test this weekend. If that works then I will make the CSV a full time manual and even further improve the voltage during starting.

Very interesting to know that the newer ball valves have a direct correlation to the elimination of the Start solenoid. I knew there was an improvement, but didn't know what it was.

Great tips and thank you!

[Tyler S]

Wallace, your not crazy. I think it is a combination of the solenoid, relay, and the extra load the injection pump is put under when having to go rich- those 6 little plungers have to pressurize and move more fuel.

[Benz Dr.]

Also known as a Viagra switch.

[ja17]

Hello Arthur,

Nice to see you here again. your wisdom is appreciated. I am not a big fan of the add-on switch, but I like the idea of the newer ball valves and the elimination of the solenoid. 

[Cees Klumper]

Welcome back Arthur!

[A Dalton]

 JA

I agree.
The ball valve and sol eliminate are the main upgrade for these early pumps and brings them  up to date of the later style pumps design  improvements.
I actually prefer upgrading the early pumps b/c they have their own oil reservoir.
Later crankcase oil fed pumps are using engine oil , which can be contaminated with gas/sulpher. etc........
It is easy to see why they made that lube change, but fellows who care and feed their pumps seem to agree on this point.

On the cabin sw mod, it should be noted that this mod in no way interfers with the Factory stock system design. It is simply a By-pass/Over-ride of that system.  When not used , the system is stock and has not been rewired/re-designed in any way.
It simply give the operator the option of a manual squirt to aid in certain conditions.  The perfect example would be the infamous Heat Soak condition the later systems had on hot starts.  They did make the 1 sec relay kit to add to these systems as a remedy, but the man cabin takes having to add that facory mod off the table.
I personaly never liked that mod and think they were looking for a quick fix.
Much has been written on the matter.

 So, a cabin sw addition hinders nothing and there are times when one will be happy to have it available.

May never even need to use it, but choice is nice.


  I have always been amazed that these systems  can and do work as well as they do w/o the aid of  closed loop technology... and there is not a " one size fits all"
tune process...they all need individual tweaking and they do respond well to adjustments.

A mechanical marvel, to say the least..

These thought are only personal observations from my experiences with these systems and not meant to be the rule... simply  passed on info.

[Tyler S]

The simplest way to wire the switch would be on the passenger side near the CSV. There is already a keyed B+ wire for the radio and a grommet to run through the firewall.

There are a lot of creative ways to hide a momentary switch. On a previous vehicle of mine, I used a relay that was energized by grounding its coil through the cigarette lighter element. To start the car you would have to light up a smoke! 

[wwheeler]

I am not super excited about having to add this switch, but I have tried everything I know to get the factory systems to work as designed. Worse than the added switch is when you are at a car show and your car takes several short cranks to fire up. The CSV switch fixes that I hope.

Arthur was a bit before my first post in 2007, but his reputation is legendary. In fact I used his rear axle alignment diagram to make my own tool. Worked perfectly!     

Concerning the drain from solenoids during starting on automatics: wouldn't the 3 way transmission solenoid be a big drain? With the pedal not depressed and engine cranking, the solenoid is at the low pressure position and drawing power to do so. If you depress the pedal, say half way, the solenoid release to the neutral position and no power draw. I am pretty sure depressing the pedal 1/2 way at cranking speed has very little effect on the fuel mixtures because of the governor in the injection pump. What do you think?   

[Tyler S]

Wallace. Keep in mind the "factory systems" didn't always work as designed. Hence the dealer mod of adding the one second relay. It may be from Mercedes but its still a "mod", Added after the cars were already on the road. So dont beat yourself up too much about adding another starting aid.
If you want to hide it a bit you could intercept the wire on the drivers side at the relay on the load side terminal. Would be really easy for a black wire to be visibly lost under everything in situ there.

On a second note, replacing my starter with the updated higher speed unit really helped the overall "startability" of the car. I also replaced the battery cables at the same time so cant say the starter was 100% the result. But close to it. The faster that IP spins, the quicker you get delivery.

[wwheeler]

Good point on the new starter and I already have that as my original went kaput a while back. I have a 123 distributor and so I have already bypassed the resistor. Good thoughts. What do you think about starting with the pedal half way to de-energize the trans solenoid? It is a big one compared to the CSV solenoid and would seem to have more of an effect on starting voltage.

I just hooked up a temporary CSV bypass switch and it works. Now for the test tomorrow. I did jump off the aux. radio terminal block and is powered at the #1 key position. If this works, I'll go back and pretty it up a bit.

I wired the CSV solenoid so that there is no input from the thermo time switch. So for now it is a totally manual system. Do you see any harm in leaving the power wire from the TTS relay on the solenoid and simply adding the new switch wire to that? That way you would have the TTS control the CSV in situations below 95*F or so and then manual when you want it.   

BTW, it is hovering around 90 to 95*F as I type in Dallas, so the CSV would never operate automatically in this weather. This is where I think the manual override will come in handy.

[Fintail]

Hi Mr Dalton

Is there a part number for the new ball spring type upgrade? Thank you in advance. Are the non return valves for a 230 pump smaller, requiring a different part number.

regards John

[mbzse]

.../... the new ball spring type upgrade.../..

Some info in this thread
http://www.sl113.org/forums/index.php?topic=7684.0
/Hans S

[Tyler S]

Do you see any harm in leaving the power wire from the TTS relay on the solenoid and simply adding the new switch wire to that?

Wallace, You should leave everything connected as be and ADD your switched power directly to the wire for the CSV solenoid. Either at the solenoid itself or at the other end of the wire near the relay, on the "load side". This way you are not energizing the relay when you push the button. The relay is there to handle the current that the CSV solenoid draws. The TTS Is not rated to handle this larger current draw, so the relay was used.
This way it will still be functional automatically at cooler temps. You will have to learn when the car will require the extra shot. Will take a bit of trial and error. Take notes of your temp gauge when the bypass is required.

[Jonny B]

There is also a detailed description of the parts and such in Pagoda Notes Volume 8 No 1, article by Richard Simonds.

[ja17]

Now consider that the starter upgrade has the extra terminal which energizes during starting. It can be used for a ballast resistor by-pass for starting. It can also be used to eliminate the relay and wiring for the injection pump starting magnet. With cars that have the starting solenoid energize during all starting, the starter solenoid can be used in place of the original relay and wiring!

[wwheeler]

Unbelievable, unbelievable. That is all I have to say regarding the manual CSV switch. With the start solenoid disconnected, the CSV solenoid disconnected, I used a manual switch used to activate the CSV. I hadn't started the engine in three weeks and normally would take 2 or 3 cranks to fire up. I activated the fuel pump, gave the CSV switch two quick hits and cranked the engine. Wow! 1/2 second crank and the engine fired up and ran great. First time in years that has happened.

I was so excited by that, I hooked the CSV power wire back up and simply added the new switch so that when cold, the CSV would activate as normal but then I could add fuel as needed. So then I tried to start when the engine was around 110*F. I did only one short manual burst and same result - 1/2 second crank and the engine fired up. Amazing! Btw, the hot starts are still quite good and I do not add any fuel for that. It seems that as Arthur said, firing the CSV before the engine cranks is quite helpful. 

Over time, I will know when and how much fuel to add and will make this switch a permanent feature. The power for the switch came from the radio power take-off. In my case, the manual switch resolved my fuel issues during starting.

[Tyler S]

Wallace,
I have come up with what I think could be a solution to a functioning enrichment solenoid for our modded pumps with the newer ball style delivery valves. As we know the engine is over-fueled and floods out with the solenoid connected and starting the engine warm or hot. My idea involves removing the enrichment solenoid relay ground wire (pin 85) from the fender well mounting point and tying it into pin 85 of the cold start valve (csv) relay. This would allow the enrichment relay to only be energized when the engine is cold. Would effectively only be energized when the CSV relay is also energized. Would still help out during cold starts but would be disabled for warm or hot. I will do some testing and report back. If it works out I will start a new thread in the Research & Development section.

[wwheeler]

That sounds like a brilliant idea! I was on the verge of permanently mounting the manual CSV switch, but I think I will hold off. Yours could be the best of both worlds. No odd additional switches on the dash and is automatic. I understand what you are proposing and makes sense to me.

My solution over the years was to back off the start solenoid engagement so that it wouldn't enrich the pump as much. Hot starts kept getting better as I reduced the rod's length. But then the cold starting also began to degrade. I was OK with that because I would rather have a cold engine needing longer cranking times rather than a hot flooded engine that won't start.

I did measurements last month to determine how far the solenoid rod has to protrude in order to contact the rack. From that, I adjusted the rod back so there was no rack change with the solenoid connected. That is where the solenoid is today. I have kept detailed records so I know exactly where I started.

So if your plan works, I will go back to factory specs on the solenoid and see what happens. Thanks!

[ja17]

The latest version injection pumps had no enrichment solenoids at all. Also no deceleration solenoid.   Don't forget that there are four or five  different versions of starting aids on these cars. The different  types of components, their function and their quantities will vary between the types.

[Pagoda_84]

I literally have the exact opposite problem.

My 280sl is really hard to start when it's cold. It takes a lot of cranking, splutters a bit and then when it eventually comes alive it runs really nicely.

When it's warm, it starts instantly, almost on the first turn.

The engine runs smoothly all the time but I do notice some black smoke on heavy throttle, it's particularly noticeable at night in the car behinds headlights. It looks like fuel smoke to me....

Do you think my car is running in cold start mode all the time or something? It seems to use a lot of fuel also.

[Benz Dr.]

Take the small air filter off on the warm up regulator ( WRD ) and see if any vacuum is present after the engine is at full operating temp. This often involves driving your car to get it fully warmed. If you have a small amount of vacuum it's not shutting off completely. If you have a lot of vacuum the slide valve is probably stuck open. Either condition will result in a rich mixture.

[Tyler S]

Joe, I forgot to mention that Wallace and I both have pumps that were modded/upgraded with ball type delivery valves from the old needle and seat. So this will pertain only to those who have the same upgrade. Will edit my post above.

[Pinder]

I just spend the last few hours wondering why when my car is hot it takes longer to start. at cold its starts in 1 sec

[Charles 230SL]

Wallace, you noted earlier in this string that you backed off the start solenoid engagement to avoid enriching the pump as much (during hot start..).  Can the solenoid rod be accessed and adjusted by removing the solenoid or do you have to remove the pump? My car stumbles from over-fueling following a hot start and I suspect the solenoid is enriching the pump too much. If possible i'd prefer to adjust the solenoid rod rather than disconnect the solenoid.
thanks for any advice, Charles     

[wwheeler]

You can test this easily by removing the wire to the solenoid if you hadn't done that already. When I did this, I instantly noticed a profound change in the hot starts. No pedal needed or extra cranks. Fires right up. The down side is when cold, may take a bit more time to get fuel to start. But as I have stated, I would rather do that than over fuel which takes a significant effort to get the engine started.

Yes, you can remove the solenoid (will need a new gasket that is NLA) and adjust the rod back. You might get lucky and can reuse the old gasket. For a new gasket, you can get a 60/70 shore A nitrile or neoprene sheet rubber material that is 1/32" thick from Mcmaster Carr. I find that most fiber gaskets are too hard to seal well. The old original was some special "soft" fiber gasket and couldn't tell you where to get it. Pacific Fuel may be able to supply some.

You use (2) 8mm wrenches because there is a cone nut and a lock nut. Yes, it just that easy. But I would take very close measurements of the rod length so you find your way back if needed.

I found that in the end, I had backed the solenoid off so much, it wasn't making contact with the rack. You can measure that as well with a depth micrometer when the solenoid is off. So I just disconnected it and saved electrical draw as per Dalton. Use a rag under the solenoid when it comes out to catch oil (not much comes out though).