Book on repairing your own Bosch MFI pump

[michael70st]

I have recently published a book on the repair and calibration of Bosch mechanical fuel injection pumps. My book is aimed at DIY owners and sets out step-by-step instructions on how to completely dismantle and rebuild the pumps and how to set up and calibrate the fuel flow settings from scratch including building a home flow bench for testing.

My book was written for owners of early Porsche 911 cars and is based on the PED 6KL pumps. However, as the PED pumps are similar in most respects to the PES pumps used by Mercedes this may well be of interest to 250, 280 and 300 SL and SE owners with PES 6KL pumps or 600 owners with PES 8K pumps.

The book has been subject to peer review and has been well received by Porsche owners and experts all over the world. There have also been reviews of my book on line and in Classic Porsche and Total 911 magazines.

Full details of my book can be seen on my web site including extracts and testimonies from customers.

If this is of interest please take a look at:

www.911mfi.com

Thanks, Michael J Burgess

[mdsalemi]

Michael McKinney of Black Forest Auto in Wisconsin USA has developed a lot of tricks and techniques for repair, rebuild and calibration of the FI pumps on 1960s Mercedes.  He has spoken of producing a book on the subject.  Have you sent a copy to him?

[glenn]

Mike, Do these pumps have the helixes on the rotating pistons???

[michael70st]

Mike, Do these pumps have the helixes on the rotating pistons???

Yes, the pumps are pretty much identical except the PES pumps are 6 or 8 in line while the PED pumps are set out as two rows of 3. The pistons work the same way with helical metering lands on the plungers rotating in the cylinders. Otherwise the Piston mechanism, governor and compensator etc is the same. The only other differences are that the PED pumps are belt driven and the warm up thermostat is air heated, not off the engine coolant system.

Michael

[Benz Dr.]

My only question is, where are you going to get the parts to do these repairs? My expirience with Bosch is that they're even more anal than MB.

[michael70st]

My only question is, where are you going to get the parts to do these repairs? My expirience with Bosch is that they're even more anal than MB.

I have included details in my book about parts such as the bearings etc that you can get from your local bearing supplier by quoting the references I give. These are the same for all the pumps. The  gaskets you can get from Bosch via www.Partbob.com For the PES pumps you need to get the F/026/T03/028, 029 or 030 kits for the pump dependent on your MB car and the F/026/T03/031 or 032 for the governor housing. With new screws and circlips which you can get from any good nut and bolt supplier. That is all most pumps need, as they are usually just leaking at the seals and gaskets, gummed up with fuel residue and worn on the bearings. 

Michael

[georgem]

I appeal to the administrator to stop this thread immediately - its bordering on heresy!!. 
How can we as a group tolerate some Johny come lately - probably carrying IP pumps in a carpetbag, telling us that pulling down an IP pump is NO BIG DEAL. Come on..............  we all know that even the thought of taking one off requires a college education and actually taking one apart is a black art - steeped in medieval rituals and customs known only to the annointed few.

Whats next - someone coming into the group and telling us that removing the instrument cluster is a 5 minute job, that bleeding the clutch can be done with a special sequence of pumps of the pedal, that a wheel alignment can be done with a box cutter and a bit of tape.........
No I`m for stamping it out right now before it gets out of hand!

Oh ... and have a nice day

George

[Benz Dr.]

I appeal to the administrator to stop this thread immediately - its bordering on heresy!!. 
How can we as a group tolerate some Johny come lately - probably carrying IP pumps in a carpetbag, telling us that pulling down an IP pump is NO BIG DEAL. Come on..............  we all know that even the thought of taking one off requires a college education and actually taking one apart is a black art - steeped in medieval rituals and customs known only to the annointed few.

Whats next - someone coming into the group and telling us that removing the instrument cluster is a 5 minute job, that bleeding the clutch can be done with a special sequence of pumps of the pedal, that a wheel alignment can be done with a box cutter and a bit of tape.........
No I`m for stamping it out right now before it gets out of hand!

Oh ... and have a nice day

George

Well........ Uh...... OK, I was going to say something like this and thought about it for a while...... and came up with this instead:

Simple external adjustments can be made and if you're lucky all will be well. Getting ino the pump is possible but putting it back together isn't so easy - or I've been lied to for the past 20 years. I won't take one apart because:
 a) I don't have the special tools to put everything back together
b) I've been told that you need the test sheets only supplied by Bosch
c) you need all of the parts which are only supplied by Bosch to Bosch dealers

I'm pretty good friends wth several Bosch dealers and they will not sell pump parts directly to me. I'm not a Bosch dealer and I have zero training.

The only thing that bothers me about this that some people will think this is something they can do without any expirience or knowledge. Good luck to yah.........

[DaveB]

bordering on heresy!!

Indeed!
As long as you keep all the parts I guess the worst that could happen is you fail and have to take your box of parts, tail between legs, to a specialist.

[Benz Dr.]

Want to know how times many I've been given that's all in pieces or partly assembled? My pump guy told me he wouldn't do another one like that because none of the parts were marked for each individual injection element. If you get them mixed up, that's not good. I'm sure a detailed manual would explain this important step.

  I have zero problems with a new guy out there who rebuilds pumps - that's a good thing. Maybe someone like Joe or others who have messed with pumps might find such a book useful in some way but there are two big impediments to consider - parts, and test equipment.
 Frankly, I wouldn't install one of these home built pumps on one of my cars. Even the experts can have problems making them work right. It's fine when everything is working but what happens when it doesn't? Only knowledge and expirience can teach you some of these difficult things.


I'm someone who encourages people to learn about new things. Part of learning is knowing when it's best to take your stuff to the experts because they have the skill sets to effect such repairs. After I tried some things myself, I decided it was better to use my time on the things that I'm good at and not try to do everything myself. Personally, I don't think there's any worse feeling than when you start to realise that you're in over your head.

I hope I've made my position clear because my intention is not to rain on anyone's parade. 

[912uk]

I would say that if some one has taken the time to put some thing togeather then that is a good thing.

MY view of this is that the Porsche world for which I have also a classic 60's Porsche is full of Tec bods who between us all have come up with a number of solutions and the whole scene is VERY active and I mean VERY active.

From people making spare parts for them and others that are no longer available to one guy I know who repairs MFi units as he has worked out how to fix them and repairs them on a return to owner basis.

This has not been overly the case with mercedes groups that I have come across so far. Restoring two cars Porsche and Mercedes are totaly different followers. I don't want to upset the Mercedes people as there are some amazing people who have learnt them selves but there are alot who just give it to the local repair shop and then tell every one how good the repair was.

One thing I will say is this..


The craft of repair and looking after these old cars is a dying art. We must stick togeather, work out what others learnt, died and took it with them to the grave instead of putting it down on paper for others to learn from..

If we tell every one what we learnt then no one new has to start reinventing the wheel.. 

[Benz Dr.]

While I agree with everything said above it doesn't always work out that way. On a regular basis, learning how to repair diffficult things can be useful to you. If you want to become a rebuilder, it's essential.

 For the one time project of the one car owner? Better go to a competent rebuilder. Those who won't heed this advice will learn the hard way.