Bosch Mechanical Fuel Injection Pump

[n/a]

A couple of years ago I bought a 1965 230 SL 4 speed manual for restoration.  As of 3 months ago most of the work had been complete untill I ran into the brick wall.  The body was 100 % restored with all new chrome and accessories imported from a very reliable supplier in Hamburg called SLS.  The engine was also overhauled as well as all other mechanical parts.  The brick wall was that the engine would start off to run very smoothly eventually to run into problems of not effeciently burning fuel.  We found that the fuel in the tank became contaminated by motor oil.  We decided that the MFI was in need of service since it was mixing motor oil and fuel.  This contaminated fuel is taken to the tank via the return line.  

The local Bosch dealer seem to be competent enough to handle the service except that they do not have any of the repair kits, elements etc in order to perform a complete overhaul.  

I need help.

1.  I need the mercedes part number and bosch part number if available for this MFI in order to find another supplier.

2.  Can anyone help me identify the list of parts that probably need changing and who could possibly supply them.  As further information, my car was imported to Ethiopia in 1966 and has been poorly serviced.  It was parked in a garage for some 10 years before I bought it.  How much should I expect to pay for the overhaul kit?

3.  How reliable are reconditioned MFI's.  It would help if there is any member that replaced one either using a brand new one or a reconditioned one with details.  How much should I expect to pay for either of these in the USA.  My contact in Hamburg want around Euro 2,500 for a new one.

Any help is much appreciated

Workineh

[Cees Klumper]

I am not sure rebuild kits are available through 'normal' channels. I would have expected your Bosch dealer to have access to the proper parts and the correct part number information, but I guess that is too much to ask in Ethiopia.
Rebuilt pumps vary in cost. New ones are more expensive than the EUR 2,500 you were quoted. These pumps rarely break down, and you might be able to find a good used one for far less than EUR 2,500. The Technical Data Manual lists the pump number (to be found on a metal plate riveted to the pump body) as PES6KL 70-120R11 127 070 07 01. In the vendor database, there are several sources that rebuild FI pumps, also in the US, you might ask them for a quote, describing the symptoms to them.

Cees Klumper in Amsterdam
'69 white 280 SL automatic

[n/a]

Thanks for the prompt response

Actually it is not too much to ask - they are very capable and the Mercedes and Bosch dealer is one company and they have been around since the mid 50's.

I did not want to use them to import the necessary parts since import duties are high not to mention the dealer's margin.  I was intending to locate my own source to compare the prices they give me

Anyway, thanks for the info

For your information - I bought all parts for my restoration from SLS GMBH Hamburg and they have a very efficient service and a useful catalogue they provide free of charge and their prices are very reasonable.  For example they have the MFI labled as part number 207111 and their price net of 16% VAT is Euro 2314.04.  They also produce a wide variety of parts under license from Mercedes Benz - I have visited their set-up in Hamburg and it is very impressive - and the staff are very friendly -

Workineh Yemesgen
1952 Chevy Styleline
1954 BMW 502 V8 Ex-Haile Selassie
1957 Mercedes 190 Ponton
1957 Mercedes 220 Ponoton
1961 Mercedes 180c Ponton
1964 Mercedes 220SE Fintail
1965 Mercedes 230 SL
2003 Mercedes G 270

[A Dalton]

<This contaminated fuel is taken to the tank via the return line.
>

 Be aware that the pump on that engne does not use an engine oil recirculation system, but rather has it's own small self contained  oil resevoir.
 If  oil is causing plug fouling, I doubt the oil to be coming from oil contaminated gas caused by the tank return of the pump.
 However , if the pump is not puttng out correct pressures , you may want to check the dip stick to the pump oil resevoir.
 If there is a concentration of oil mix in the tank, it may be that someone put some oil additive in prep for storage , but if you took the entire volume of oil in the FI pump and put it in a tank of gas, it would not amount to enough of a mix to foul ignition [ if that is what you mean]..
 

[n/a]

I am pretty sure I have the one with the oil recirculation system and not the self contained one.  By the way, I thought all three 113's shared the same standard FI pump.  Are there pros or cons to either type??? can you provide a scanned picture of what the self contained one would look like or where the resevoir would be located?? - what I did try was that I emptied the entire contents of the tank and added fresh fuel and the engine ran better to smooth and about after sometime became sluggish again.  I then checked the fuel in the tank and it is tinted by engine oil.  Does this mean that the FI pump puts our good pressure but somehow needs to change some seals etc?  Right now I am weighing towards buying a new one.......?

Workineh Yemesgen
1952 Chevy Styleline
1954 BMW 502 V8 Ex-Haile Selassie
1957 Mercedes 190 Ponton
1957 Mercedes 220 Ponton
1961 Mercedes 180c Ponton
1964 Mercedes 220SE Fintail
1965 Mercedes 230 SL
2003 Mercedes G 270

[mulrik]

I would be VERY surprissed if you have the recirculation injection pump. they were only installed on late 250 SL's or 280 SL's I never can remember. In any case I have a very early 250 and it has the selfcontaining one.

Good luck
Ulrik


'67 250 SL Papyrus White 113043-10-000023

[Ben]

You would want to have  a lot of oil in the tank to cause poor running. Fuel that is tainted with oil wont cause poor running. A lot of folk add either marvel mystery oil, 2 stroke engine oil or regular engine oil to their tanks on a regular basis just to lubricate the seals in the pump.

I have added oil to a full tank, full tank about 60 litres, added 1/2 litre of oil, with no discernable difference!

There may be something else causing the discoloration of the fuel....rust ! If the car was laid up with some fuel in the tank this may be the problem, and you will need to boil the tank, clean and blow out the lines and change the fuel filters and clean the various strainers.

As mentioned the pumps ARE reliable and if the car drove in there it should drive out with the above work done. You may simply have an issue wih the Warm Up Device !

If the pump has a dipstick on the rear then it is the earlier type !

Nice collection BTW !!

Regards,
Ben in Ireland.
'64 230SL 4sp.
'03 CLK Kompressor

[rwmastel]

Workineh,

Hello and welcome to the Group!  I have one piece of advice for using this discussion forum, use the Search tool.  The link is located in the upper right corner of the screen.  I searched on "injection pump" and found the following links to existing discussions.

http://index.php?topic=1712

http://index.php?topic=1654

http://index.php?topic=1586

http://index.php?topic=1323

http://index.php?topic=1154

http://index.php?topic=1153

http://index.php?topic=950

http://index.php?topic=898

http://index.php?topic=886

http://index.php?topic=852

http://index.php?topic=790

http://index.php?topic=684

http://index.php?topic=662

http://index.php?topic=412


Please read all these links.  Knowledge is power and this forum is here to give people knowledge, so please take the time to read through these.

Let us know all the thoughts and questions you have after this education!  We're more than happy to help.

Thanks,

Rodd
Powell, Ohio, USA
1966 230SL, Euro, Auto, Leather, both  tops
1994 E420

[A Dalton]

If the car is running too rich after warm up, then a suspect for this condition is a leaking  cold start valve.  This is a common
fault on cars that have sat for periods.
I would check that before the pump and I would also check the oil level on the res of the pump.
 You can feel at the back casing of the pump for a "T" handled dip stick. It is removed by unscrewing and it has a level indicator line on it.
 This chassis has an R11 pump and is so equipped with the dip stick/resevoir.

[n/a]

Thanks everyone for all the help-

Here is my progress report.

I dismounted my tank - cleaned it out and then boiled it - I did find oil residue and believe my tank to be in good condition.  I didn't mention that my car had been in poor storage as part of an estate for 11 years and I should have taken the time to clean out the fuel system completely.

I put everything back together including a new set of spark plugs, high tension coil etc.  The engine started out fine - after about half an hour idling I could smell the exhaust had traces of a rich fuel mixture - went back to our web site and did some 'education', I noticed that while my engine was hot, the water line to the MI pump was cold!

Checked for a missing thermostat on the engine and sure enough it was missing.  I found the thermostate part # 110 ..... at the local Mercedes dealer and fitted it and so very slight improvement in the temperature of the hose.  Decided to dismount and check the thermostat on the MI pump and to my disgust it was completely clogged with rust and silt - I suspect the previous owner foolishly used plain water and no coolant.

I marinated the unit with a little break fluid for about 8 hours and washed it out clean.  I found no washers and would have removed it anyway.  Put everything back together and ran the engine - this time the temperature in the pipes and the thermostat housing rose with the engine and the engine now ran dramatically better and wasn't wetting sparkplugs anymore.

I would say on the whole I am very happy to report seeing a 90 % improvement but smoke due to rich fuel mixtue is not totaly elliminated.  I am planning to go for a test drive this weekend to see if I can burn any residue in the exhaust system - but should the above condition be acceptable if the engine has been idling for a good 3 hours without being driven out on the road or should all smoke be elliminated?  Does this make sense?

Also, I can hear a very slight moaning/crying sound coming from my MI pump - I can hear this same sound a little more exagurated when the engine is not running and the ignition moved one click thereby turning on the pump?  I apologize if this is not clear.  BTW the fuel in my tank now has no trace of oil or any other contaminant.  Thanks for all the help and its great to have access to all this priceless info

Workineh Yemesgen
1952 Chevy Styleline
1954 BMW 502 V8 Ex-Haile Selassie
1957 Mercedes 190 Ponton
1957 Mercedes 220 Ponton
1961 Mercedes 180c Ponton
1964 Mercedes 220SE Fintail
1965 Mercedes 230 SL
2003 Mercedes G 270

[Benz Dr.]

MB supplies almost nothing in the way of parts for the IP. Any available parts are VERY strictly controlled by Bosch and their authorized agents. Last time I looked almost every part is still available but at high prices.

Daniel G Caron

[rwmastel]

Workineh,

Congratulations!  It appears you resolved some significant problems.  Another spot to inspect that may cause a rich running condition is the cold start valve, which is attached to the side of the intake manifold.  It's purpose is the give extra gas for 1 or 2 seconds during startup, but over time it becomes leaky and provides fuel all the time, which of course the engine is not tuned for.  Search for CSV or Cold Start Valve.

I would say you won't be able to truly analyze your exhaust smoke and spark plugs until you get the car on the road and put the engine under a load.  I don't know if letting it idle for a long time is a good test.

Also, consider buying or borrowing a gas exhaust analyzer.  This helps you fine tune the engine by measuring what's in the exhaust.

Keep up the good work.

Rodd
Powell, Ohio, USA
1966 230SL, Euro, Auto, Leather, both  tops
1994 E420

[n/a]

Thanks

I have replaced the cold start valve (next to the coolant resevoir on the intake manifold) with a new one from SLS.  The problem I am having now is good cold start but problems starting when enine is hot.  The cold start solenoid on the pump works but I have narrowed my problem down to the small thermostat/switch on the 'coolant temperature switch housing' (refer to Haynes page 39 fig. 35.6A)  If my understanding is correct, this switch is suppost to disrupt electric flow to the solenoid on the pump when engine is warm.  I tried starting the engine when hot - nothing - I disconnected the relay controlling the cold start solenoid and the engine starts no problem.  I took off the above mentioned thermostat and applied heat and it does dissconnect - I am not sure it does this at the right temperature - can you tell me at what degree this is set at to determine if i need to replace this part?  My guess would have to be something like 20 degrees C?!!  Am I on the right track?

Workineh Yemesgen
1965 Mercedes 230 SL
Dark Blue Metalic
4 Speed Manual, Both Tops

[hands_aus]

That is commonly called the "Thermo Time Switch"
It is designed to work only for very short periods of time (usually 1-2 seconds but can be as long as 12 seconds) based on the engine temperature.
The cold engine temperature is about 35C degrees.

Do a search for Thermo Time Switch. There has been a lot of discussion about these things in the past.
 
One comment, they are not cheap to buy. So make sure that is the problem and not the CSV relay.

Bob (Brisbane,Australia)
RHD,1967 early 250 SL, auto

[n/a]

Hello again
I use the search feature a lot now and after doing much reading, decided that I need to install a heavy duty coil on my 230 SL rather than the typical one on there now that you would find on a typical 80's Japanese four cylinder run-around.  So I went down to the Bosch dealer and they do have heavy duty ignition coils.  They offer two kinds for sale.  One has a register included and sells for about USD 40.00.  The second one has no register but suprisingly sells for USD 70.00.  I realized just how much I have come to depend on our website because I normally am decisive and would have made a choice based on what I thought was correct.  However, I wrote down both Bosch part numbers and told the clerk I would be back the next day because I had some very knowledgeable friends that I needed to consult.

So here is my choice

1.  Heavy duty coil with register Part #: 0221 119 031  
2.  Heavy duty coil without register Part #:  0221 118 307


Thanks for all the help

Workineh Yemesgen
1965 Mercedes 230 SL
Dark Blue Metalic
4 Speed Manual, Both Tops

[graphic66]

I put the "red" coil on my 230SL The part number I have is 234-150A and another number on the box is A000 158 49 03. The coil has worked fine and mounted just like the original unit. I paid $50.00 in 2002.

[rwmastel]

quote:Originally posted by workineh

1.  Heavy duty coil with register Part #: 0221 119 031  
2.  Heavy duty coil without register Part #:  0221 118 307

Forgive my ignition system ignorance, but what is a "register" when speaking of an ignition coil?

Thanks,

Rodd
Powell, Ohio, USA
1966 230SL, Euro, Auto, Leather, both  tops
1994 E420

[A Dalton]

I believe he is referring to Internal Resistor/External Resistor coils..

[n/a]

Sorry for the confusion, I meant to type resistor - usually have trouble spelling when using my wife's french-keyboard laptop at home.

A. Dalton's post ponders yet another question, could the bosch coil part # 0221 118 307 already have an internal resistor?

Both coils look identical - silver/chrome cylinder with red sticker - I searched 'red coil' and the closest part number I could find was 0221 119 030 and recommending one to use a 1.8 ohm resistor.

I do remember buying a resistor from SLS with white ceramic insulation and red filament - will check if I have the correct resistance ie 1.8 ohm.  If I do have the right resistor, should I install with the coil having part # 0221 118 307 - assuming that it's priced higher due to superior quality???!!!!!  Hope to make the correct purchase tomorrow morning.

Workineh Yemesgen
1965 Mercedes 230 SL
Dark Blue Metalic
4 Speed Manual, Both Tops

[Naj ✝︎]

Workineh
graphics66 has the correct red coil that Mercedes used during the '60s from what I can work out.
Merc part # 000 158 4903 is same as Bosch 0 221 119 030. You have to use it with a 1.8 ohm external resistor and is recognised by the steel fixing band on it which is red or rose color. '1.8' is usually stamped on it as well.
0 221 119 031 fits only one Merc engine - the 6.3 litre!
0 221 118 307 is listed for various Merc models from 1976 onwards (maybe goes with electronic ignition ??)
Could be worth persevering further to get the correct one.
naj

65 230SL
68 280SL

[graphic66]

The part # for the resistor to use with the red coil is 234-158c