New to This Site - Injection Pump Solenoid

[67 250 sl]

Hello to all,

 I hope to be a asset to as many people here as possible.  I have been a Mercedes technician in a dealer since 1986. I do all of the 1992 and older cars in our shop.  I have a 1967 250 sl of my own.  I have visited a lot of other sites in the past and never been impressed.  This is a great site with good information. I recently put in a used injection pump from a 1969 250 s in my 250 SL  I have worked on these cars but never had to do a pump.  The pump is a little different in that it has two solenoids on the rear of pump verses the one solenoid my original pump had.  I have not found any information on what these solenoids are for.  Any explanation would be appreciated  on that same note. when installing the pump I did break the electrical switch directly above the injection pump. The wires do go to the solenoids mentioned.  

Thank you in advance for your help.

[w113dude]

Did you get to read this? There is a lot of info.
http://www.sl113.org/wiki/Fuel/Injection#Pump

[67 250 sl]

I did read this document word for word.  I found it in the technical manual on this site. However while trying to view some  of the information. A  log in page pops up and asks for a username and password.  I did sign up for the site and that username and password does not work.  Do I have to be a full member to view some info?  There is great information in the fuel injection portion, while looking at the early pump picture compared to the later pump picture. You can see the solenoids on the rear of the pump.  There were two wires connected to my original solenoid.  The donor pump had two solenoids and a single wire to each.  The wire colors from the donor pump matched my engine harness wires so I assumed I could just use these wires.  I have been unable to find a wiring diagram or a description of these solenoids.

Thanks for your response.

[w113dude]

Connect one of the two wires to the solenoid below the bigger one, one at a time to see which one pushes the rod at staring, that is your starting solenoid. You really need this part to work along with cold starting valve (on the side of manifold) otherwise you'll have tough starting.

[ja17]

Hello,

The earlier pumps had just the top solenoid which is a starting aid. Later came the pumps with two solenoids. A second lower solenoid was a fuel shut off device which moved the rack to full lean (no fuel) during decelleration. This was an emission device. The latest version of the IP was improved so that no starting solenoid (top solenoid) was used and it was illimnated all together. Only new replacement pumps or only the latest versions had the starting solenoid illinated.  These latest versions did have the lower emission solenoids (fuel shut down).

So the historical sequence for  injection pumps in the W113 was; pumps with only one upper starting solenoid, then pumps with both the upper strarting solenoid and the lower decelleration solenoid, finally the pump with no upper starting solenoid but with a lower emission solenoid. You can look up the "R" numbers in the BBB to identify exactly which pumps were which.

Many owners and dealers, dis-connected the lower decelleration solenoids, since a malfunction in the circuit would leave you stranded.  The engine would shut down and would not re-start. The small micro-switch attached to the linkage on the firewall of the engine bay activated the deceleration solenoid.

The 250SL never had the lower solenoid as far as I know. You should just be able to hook up the top solenoid so that your engine starts easier.  Hope this helps.

Keep us up to  date,

Joe Alexander (ja17)
Blacklick, Ohio

[w113dude]

Connect one of the two wires to the solenoid below the bigger one, one at a time to see which one pushes the rod at staring, that is your starting solenoid. You really need this part to work along with cold starting valve (on the side of manifold) otherwise you'll have tough starting.

OOPs I had it wrong.

[ja17]

No big deal Shaun, I "oops"  myself from time to time. Usually someone like Dan, Naj, Alfred or Achime, keeps me in line!

[Peter van Es]

Do I have to be a full member to view some info?

Yes.

[67 250 sl]

Wow,

 All of you guys are incredible.  Not only do you give  information it is the correct information.  It is a pleasure to finally find a site that has  experts on these fine automobiles.  That enjoy helping others  with good information as much as they quest for good information when they are in a bind.
I do have it running and it will need some more tlc when I have more time. 

THANKS!!!!!!!!!!!!!!

[RBYCC]

Hello,

The earlier pumps had just the top solenoid which is a starting aid. Later came the pumps with two solenoids. A second lower solenoid was a fuel shut off device which moved the rack to full lean (no fuel) during decelleration. This was an emission device. The latest version of the IP was improved so that no starting solenoid (top solenoid) was used and it was illimnated all together. Only new replacement pumps or only the latest versions had the starting solenoid illmiinated.  These latest versions did have the lower emission solenoids (fuel shut down).

Joe

I have the R24W FI pump which has no solenoids be they top or bottom on the back of the pump.
My 1971 280SL is a USA delivery, so should I assume that the pump has been changed out at some time?
Based on the pump should I also assume that the speed relay and relay box are no longer active?
Car has passed state emissions testing over the past six years.
Cold start with no problem.

Trying to wake the car up this year and it ran, but after 5-10 minutes stalled, initially able to start, but then only crank.
Narrowed it down to an aftermarket coil ( KEM U12K with no ballast resistor ).
Transistor ignition has been disconnected, so I ordered a Bosch red coil with the red ballast resistor.
If the coil was the "only" problem, I'll run it for a while and then consider a Pertronix module.

Any experience with the Ignitor ( 1864LA ) versus the Ignitor II ( 91864LA ) ?

Thanks !

Ed A.

[ja17]

Hello Ed,

Very interesting, my books show the R24w pumps used on low compression engines, or for "Europe Esxhaust Emission Control" and "Sweeden Exhaust Emission Control" engines. This information is part of a July 1973 Suppliment 3 of the BBB.  p. 07-0/3. Are the openings in for the solenoids not there or are they covered by a plate/plates?  The "Euro" Emission pumps had red identification plates. The whole id number should help if you can get it. 

Np experience with the ignitor.  The red coil and resistor should be fine. You may need to look into a standard non-transistorized ignition condensor if you have issues.

[RBYCC]

Hello Ed,

Very interesting, my books show the R24w pumps used on low compression engines, or for "Europe Esxhaust Emission Control" and "Sweeden Exhaust Emission Control" engines. This information is part of a July 1973 Suppliment 3 of the BBB.  p. 07-0/3. Are the openings in for the solenoids not there or are they covered by a plate/plates?  The "Euro" Emission pumps had red identification plates. The whole id number should help if you can get it. 

Np experience with the ignitor.  The red coil and resistor should be fine. You may need to look into a standard non-transistorized ignition condensor if you have issues.

Thanks Joe

Difficult to see but the lower rear pump position appears to have a plate and the upper appears to be just the blank casting.

The numbers are stamped into the side of the casting, again diffcult to see but can read: "70B 120 R24"

The car was last tuned in 2007, not many miles since then as I was working on another Merc project.
Distributor is 0 231 185 009 and has an external condenser.
Cap, rotor are pristine, points very little wear.
Plugs were black and fouled possibly due to weak coil?
Just installed fresh NGK BP5ES gapped at .030.

Ed A.

[RBYCC]

Joe

A pic of the IP nameplate..not red but black and silver.
Appears to read:  PES6 KL 70B 120 R24




Hard to get a pic of the back of the IP...best I could do:





Hope this helps !

Same IP on EBAY UK with black/silver nameplate:

http://www.ebay.co.uk/itm/MERCEDES-280sl-injection-pump-assembly-113-Pagoda-PES-6-KL-70-B-120-R24-/350520745147?nma=true&si=iRFripKXGhJ%252F7WmwHDci5G6nvjw%253D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557

Thanks

Ed A.

[ja17]

The bolt missing on the bottom rear mounting bracket, may be an indication that the pump in  your car had been changed at some point. Seems that it could be an Euro pump and possibly for a low compression engine. Makes sense that the latest Euro pump may not  have the fuel shut off solenoid that was added for USA Emissions.

So we find that there is a fourth configuration..... the Euro late pump with no solenoids!

The part number confirms that it could be a Euro Pump (late version)

[RBYCC]

^

Thanks Joe !

You have a great eye....
I'll need to find bolts and the missing bracket !!!

[ja17]

Hello,

It's not a critical mounting point, and it can be very difficult to get started after all the other mounting bolts are tightened. I like to start it before everything else is tightened down. In addion this bolt chqanged from M5 to M6. The hole in the bracket was increased at the same time.  You'll have to determine if your threaded hole in the engine block is M5 or M6 first.

Try installing it from below the next time you have your oil filter canister off. You'll have a little more room.

[RBYCC]

Joe

Your input is always appreciated !!!

Bosch red coil coming today, red resistor in my hand and hope it now starts !!

Ed A.