FYI, I've made some interesting connections at Bosch, in the Bosch Automotive Tradition group, which is dedicated to supporting classics. I'll have some more info for everyone soon. They're starting a their own program of rebuilding components. They already can do the AAR, and will be starting rebuilding MPS's next month - to Bosch standards, with Bosch parts, and Bosch calibration standards. No idea of cost or logistics. Will pass on more info as I get it.

OK, here's a bit more info. There's a newsletter you can subscribe to at the Bosch Automotive Tradition web site, see:

http://www.automotive-tradition.com/en/new...x.htm?locale=en

Here's a link to the December issue:

http://www.automotive-tradition.com/en/new...r_dez_09_en.pdf

Open it and you'll see an item about "Individual Remanufacturing of Induction Tube Pressure Sensors" - a.k.a. the manifold pressure sensor. They have a link to their 1:1 REMAN site with more info. This site has a lot of information available over in the sidebar under "Parts".

They're also interested in remanufacturing the throttle position sensor. Since we already have someone doing that, I'm going to try to get them hooked up.

IMO, if we could get Bosch to do a rebuild and recalibrate at a "reasonable" price (IMO, $300 USD), these rebuilds would likely be as good as or superior to anything we'd be able to do on our own. Worth a try, at least.

While you are on a roll,

Howsabout fuel injectors.......

We should give them a list and have 1,000 members sign it ...
Andy

He asked me about other problematic parts, and fuel injectors were at the top of my list.

Brad's link links to Bosch Traditions, which in turn links to their storefront on eBay-Germany. They have all three of our fuel injectors! Take a look- about 160 Euro.

Click to view attachment

Here's the link- http://cgi.ebay.de/0280150019-Einspritzven...=item1c0d943de0

and the yellow one (1.7) is here-
Click to view attachment
http://cgi.ebay.de/0280150009-Einspritzven...=item19b83b241c

and the 1.8 is here-
http://cgi.ebay.de/0280150112-Einspritzven...=item19b7831b74

Did anybody say throttle position sensor?

Here's the 1.7L http://cgi.ebay.de/0280120021-Drosselklapp...=item1c0f9b1e8c
Click to view attachment

And just to tease us- here's an MPS for a Opel Admiral- Later type, no diaphram, but it's "only" 175 euro. If that's the ball park for a -037, -043, or -049, COUNT ME IN!! http://cgi.ebay.de/0280100105-Saugrohrdruc...=item19b5a0393d
Click to view attachment

Yikes...that's $218 US dollars
Great Thread and Read!

OK. How'd you get the English version?!?!?!?!?!

Jim

Nevermind. I found the english version at eBay-UK. Groan. They list a -066 MPS, which is our type with the diaphram, for 1050 euros. That's $1437. But that's brand new. (-066 is for a Volvo 3.0L six cylinder.) Maybe there's still hope for the 1-for-1 rebuild program.

http://cgi.ebay.co.uk/Bosch-0280100066-DRU...=item1c03b4aec3

Yeah, I should have been more clear. I knew the had the injectors on the site, but I think these are NOS. When they're gone, they're gone. The Reman operation is actually fabricating new parts, I'd like to coax them into remanufacturing the more "consumable" parts, including injectors.

I'm hoping to hear back from them tomorrow.

Google is our friend...translate any url.

Maybe I can send them the box of 50 dead MPSs siiting in my garage so they can fix em and sell cheap....$1000 is way too much, $300 is a good target as a brand new diaphram will last another 30 years!

Too bad you can't just get a kit. Diaphram, o-rings for adjuster screws, and main seal, for maybe $100.

Jim, tuning is the real issue with a home rebuild kit. The best part about a factory rebuild would be that it's a 5min install and you can trust that it's right.

I know. But I also I think there's an opportunity for someone to write up a procedure, maybe do a video, on tuning D-jet to their own engine. The initial tuning done by the car manufacturers was a compromise to begin with. They had to account for production variation, variation in quality of gasoline, climates where the cars would be sold and driven, etc. And they didn't have the benefit of O2 sensors and the feedback loops they provide to help tune on-the-fly. Couple that to the fact that most of us have done SOME mods to our engines, and I think time is ripe for us to figure this thing out.

I keep thinking about that 1.99L Volvo 142E being rated at 135 HP. Or the 1985cc Saab GLE at 118 HP as exemples of where D-Jet can go with the right cam, timing, exhaust, C.R., etc. Not to mention the 2L Cosworth Vega at 122 HP-

Click to view attachment

I sent an email to Bosch via the Traditions web site telling them that I'm interested in having a 1.7L mps rebuilt. Someone named Matthias responded to me saying that they are looking at pricing for this process that would be done at Bosch in Germany and to keep an eye on the newsletter.

Tuning to the known settings is pretty easy, the problem is most engines are slightly modified from stock these days. Close but tuning with a LM1 O2 setup gets you right there. New outta the box MPSs from Bosch would be set to their settings from what, 30 years ago for Brand New engines.
I have had a couple of NOS 043 that were set all over the place...and I set them to the "correct" setting I knew worked right.
I would rather have a repair kit of new parts to do the job myself so I could tune the MPS to a engine with its own quirks.

I'm with you. The carb guys haven't weighed in. Would they take a new set of Webers and plunk them onto the car, and then never dial them in? I think not.

And either way, you really should have access to an AFR meter. I'm going to try and use a PLX Devices unit. Got it for Christmas. Haven't tried it yet... And inductance meters have come way down. I think I paid $40 for mine brand new.
Click to view attachment

Click to view attachment4 new 2.0 injectors from Otto, not cheap but reasonably priced.

Matthias is the same guy I'm communicating with, same info I received regarding when the program will start. I'll communicate more on this stuff next week. I've had a medical issue since Wednesday that's kept me out of action, I should be back to speed by Monday.

Exchanged emails with Herr Matthias Klumpp at Bosch Traditions. I requested that Bosch make available a rebuild kit, composed of 3 seals plus diaphram. He replied that they were going to offer a rebuild service soon. So I replied again that the rebuild is easy, it's the tuning to the engine that is more difficult and that it really should be done for each engine anyway. So I requested again- "would Bosch consider offering the repair kit separately as described?"

Maybe with more requests they'll think about it. If they're offering the rebuild service, they obviously have these 4 parts.

Jim

I would be quite surprised if Bosch made a rebuild kit available. Pleasantly surprised, but surprised. It's not their style. There's not much money in it for them, and by keeping the price of the 'secret service' high it keeps demand for the parts low.

I believe they're only pursuing the 'rebuild service' because if emissions parts are really unavailable, they need to make this representation to the appropriate governing authorities (e.g. EPA, DOT, CARB) and that (manufacturer's NLA statement) removes the 'original equipment' requirement - which would kill their golden-egg-laying goose well and truly.

If you had only to meet tailpipe numbers and could do it with any induction system, would you do it with Bosch D-Jet parts?

Sorry to be uninformed, but what does this AFR do and how do you use it to tweak a DJet? Thanks, I am just wanting to learn how to get the most out of my setup.

Larouex

I agree, I see very little incentive for Bosch to offer a kit. I'd be glad to see one, however!

For tailpipe emissions, D-Jet is a decent solution, especially compared to some of the carb arrangements I've seen. Where D-Jet beats carbs on emissions is under all of the various running conditions outside of part-load, which is why carbs fell out of favor once the Feds started the program in '70.

One manufacturer who stayed with carbs a long, long time was Honda. Anyone remember the carbs on some of their cars from the early '80's? Absolutely insane number of vacuum hoses and tacked-on systems to manage emissions. They worked fine when the cars were new, but once the hoses started to go, look out.

First you weld a "bung" onto the exhaust so you can mount the O2 sensor.
Then you drive around at partload (2000-2500rpms) and record it onto a laptop.
Then a WOT run
Check your results and see what your AFR is varying conditions to see what your average AFR it. It should be between 13.7 and 14 to one at Part load.
WOT should be 12 to one to start and end at 13 to one at 5000 rpms.
Idle is set with the knob.

Those are the same ratios I recommend, too. If everything in your FI checks out (especially check on the fuel pressure) and you're running rich at part-load, you'll need to adjust the MPS to get the mixture right.

From what I can tell, these engines will run just fine with extremely rich mixtures, part-load at 13:1 or less. These high levels may work OK, but contribute to higher pollution, poor fuel economy, cylinder wall wear, and oil contamination.

So if Bosch does a rebuild kit over a complete rebuild I've got buy a AFR and a laptop, cut holes in my exhaust, and learn to weld? Or, I guess I could buy a rebuild kit and then try to find a mechanic that knows Djet and is willing to do the tuning at a reasonable price.

Ugg, doesn't make sense for 95% of the 914 owners out there.

I agree (again). While it may cost a wad of cash to get an NOS or Bosch rebuilt MPS, the investment in the stuff required to DIY, plus the time, is likely to cost more.

Regardless of whether the MPS is NOS or rebuilt, I still suggest a dyno evaluation for all D-Jet owners, with gas analysis. That way you'll know for sure what your part-load and full-load mixtures are. Shouldn't cost more than $100, and you'll get that cool HP graph, too.

Well, I suppose. But I'm not doing anything here based on cash flow analysis. I'm having fun, and I'm learning lots of new things. That's pretty much what I've been doing with this car for the past 28 years that I've owned it.

And I still don't see why this isn't like dialing in new carbs..... which lots of people have learned or taught themselves to do...

I have a theory on that plastic ring.....

It'd never be an either/or. Bosch would never do a rebuild kit only over a complete rebuild. So you'll never have to face this situation.

Even when Bosch comes out with a new or rebuilt MPS, everyone should do as Brad suggests..put it on a dyno and check your AFR at part load and WOT.

of find a friend who has a LM1 to check it.

The original MPSs were set up for brand new engines off the VW line. No one has a brand new engine, most rebuilds are mostly new or reconditioned parts..and who has brand new injectors, fuel pump, etc.

Any update on this? Curious 914 owners are watching!

Not much at the moment from me. I'll get back into this this winter. Rebuild of my front end will pre-empt much else for a while, though.

I was able to confirm presence of Be in my stock diaphram, using EDS at work. That's Energy Dispersive Spectroscopy. Like XRF, it also can't determine component %-age in an alloy for elements below atomic number 5 or 6, because it also depends on X-ray. The only way I've found is a "wet" process, where the sample is dissolved in nitric acid, then separated somehow into component elements, and measured. I haven't pursued where I could get this done, or for how much. But at least this is confirmed this to be a beryllium alloy. Probably any of a couple of the Brush-Wellman sheet stocks would be suitable.

Also, since I have several "good" diaphrams to work with, and I've characterized their ranges of adjustment, I'll be concentrating on how to tune them to my engine. In May, I replaced the original muffler on my Bursch system with a much quieter one, and added an O2 sensor bung. I have a lambda meter from PLX devices ready to install, along with 1K pot to replace the ballast resistor, and some assorted other parts. I'm thinking of making up a console where a co-pilot can tune some settings on the road, even (potentially) simulate an MPS with a variable inductance to establish "ideal" curve for my engine. Then see how close I can come to mapping on on the bench. Getting all the way through this process is my goal for next summer- after the front end is done.

I'll update from time to time along the way.

This is what I received from Bosch regarding rebuilding 041 MPS:



The refurbishing of a 0 280 100 041 will cost 349 EUR gross (incl. 19% German VAT) plus shipping costs.

If interested please send the MPS to my hands:

Robert Bosch GmbH
Matthias Klumpp (AA/ATR)
Auf der Breit 4
76227 Karlsruhe
Germany

I will then forward the part to our plant where the refurbishing is done. Please contact me again so that I can send you a so called "pro-forma invoice" for customs duty. Shipping should be done by TNT Express.

-> If the part is not repairable you will get it back unrepaired.
-> If it's okay (within its tolerances) we will bill you with examination costs of 19 EUR.
-> If it's defective but repairable you will have to pay the refurbishing costs by buying a special item in our eBay store http://stores.ebay.de/Bosch-Klassik-Teilvermittlung - you can pay via PayPal or via bank transfer. The refurbishing will start once the money has been transferred.


P.S.: If you have a VAT ID we can create an invoice without sales tax.


Mit freundlichen Grüßen / Best regards

Matthias Klumpp

Robert Bosch GmbH
Automotive Tradition (AA/ATR2)
www.bosch.com
www.automotive-tradition.de
stores.ebay.de/Bosch-Klassik-Teilevermittlung

Tel. +49(0)721 942-1660
Fax +49(0)721 942-2000
Automotive-Tradition@de.bosch.com

Sitz: Stuttgart, Registergericht: Amtsgericht Stuttgart, HRB 14000;
Aufsichtsratsvorsitzender: Hermann Scholl; Geschäftsführung: Franz Fehrenbach, Siegfried Dais;
Bernd Bohr, Rudolf Colm, Volkmar Denner, Wolfgang Malchow, Peter Marks,
Peter Tyroller; Stefan Asenkerschbaumer, Uwe Raschke, Wolf-Henning Scheider

fantastic news

Well, I guess it's time to get back at this. Here's my plan for the near term-
- make some new gasket sets on a laser cutter. I have a sheet of .100" neoprene, and I'll try cutting out the big ring seal and the smaller ring that goes around the outer adjustment nut. Then I can assemble a test MPS using one of the diaphrams that gave a lot of adjustment range, with no leaks (fingers crossed).

- I'm going to try and set up to map vacuum vs. lambda on the fly. I've been thinking about this all summer off and on. I picked up a Pico Technology PicoLog 1012. This is a data logger that plugs into, and is powered by a USB port in a laptop. It actually has 12 channels, but I only will use 2. One channel will be connected to the linear output of my PLX AFR sensor module. This outputs a voltage from 0-5vdc that is proportional to AFR. This is one of the reasons I got the PLX. The second output will log vacuum. To do this, I still need to buy a GM MAP sensor. These were used in many GM models in the early to mid-90's, and they output a voltage 0-5vdc that is linear with manifold pressure from 0-1bar. (There are also 2 bar and 3 bar versions for turbo applications, but I only need 1 bar and they're cheaper- about $35).

I got set up for this with the purchase of the PLX (actually a Christmas gift that I haven't tried out yet, 50 weeks later), and the install of my Walker SS muffler on my Bursch exhaust that I documented in another thread last May While I had the muffler welded up, we installed the bung for the O2 sensor.
Click to view attachment

I'm thinking the only thing left is the GM MAP sensor, and then hooking it all up.

The data logger came with software that I can set up to capture data (voltages, actually) from both channels simultaneously at pretty much my choice of speeds. It can only capture 8000 data events in it's memory, across both channels, so I'll probably start with 100 events/second, which will give me 40 seconds of data. So as I drive down the road, I'll have someone else with the lap top who can download the data once every 40 seconds or minute or so, and then start collecting again.

The raw data can be downloaded into Excel, and then plotted as a scatter diagram. I'll plot each point with X axis as voltage from the MAP, and Y axis as voltage from the PLX. I expect that as I move the throttle, the points will be all over the place because there is a lag between when the vacuum changes (throttle opens or closes) and the AFR settles in to the new point. But if I drive smoothly, with constant throttle, they should cluster about a horizontal line that roughly represents AFR at each vacuum level. I'll vary speed and even gears to get 40 second long samples at various loads.

By overlaying the calibration curve from my MPS, I can visually see where the MPS curve needs to change to bring lambda better into alignment with desired. The work I did mapping MPS adjustment ranges will feed into my selecting the right diaphram and setup to tune the whole thing in iteratively.

At least that's plan.

I've set aside trying to make diaphrams for now. Since they're available in rebuilds from Bosch (albeit at big $$), or can be harvested from 1.7 MPS's for a bit less, the common problem now seems to be how to tune the MPS to a specific engine. Whether it's a new MPS, a good used one, or a rebuild, factory settings are at best a compromise. Our engines are old and worn, or rebuilt with tweaks from original. Even a newly blueprinted engine should have it's MPS checked, because even original factory settings were a compromise in the first place.

I had a scheme where I would use a Type 3 MPS (no diaphram, only aneroid cells) as a slave, and measure vacuum level that resulted in desired AFR. This could then be translated into inductance to plot desired MPS curve. I think it would have worked, but it would have been very awkward. Then I hit on this idea.... We'll see.
Click to view attachment

I also toyed with the idea of making a test diaphram out of the sheet neoprene. It would have been an interesting experiment, and I'm sure it would have worked, at least at high vacuum and low vacuum, but I had no idea how it would behave in the transition region, or the impact of temperature or aging.

If I do decide to dabble in diaphram fabrication again, I'm sure this will be my first try. Just to find out.

Bung with sensor-

Click to view attachment

Here's a loose end from last spring. I dissected that riveted, non-leaking Volvo MPS to find a pristine diaphram. But I never showed the adjustment range, so here it is. It beats any other diaphram I tested-

Click to view attachment

Click to view attachment

Too bad. That's the one item that could help a lot of people keep their original FI ...

Wish you would make em like this! They have better transition than any of the other made.

I know. Something had to give. If I focus on making new ones somehow, I don't get my car "finished" for a while. I'm 58, and I've set an objective of having it "done" by the time I'm 60. (I started taking it apart when I turned 50, btw, after owning it and driving it for 20 summers.) So I only have 2 summers left to meet my goal. Figuring out how to tune it to a specific engine (mine, for now) helps me get there, while tooling for a new run of diaphrams doesn't. So that's the story.

I'm mulling over how to get diaphrams from Bosch. Doesn't seem right that they have them sitting over there in bins while our 35+ year old ones are dying one-by-one....

Click to view attachment

What, that's your car and its not done?
I am 58 too and miss driving my car and can't decide if I want to ship it to Suriname. There are few twistys here but there are the Saturday night drag races!

if the x-ray window in your instrument is made of berilium, detecting berilium is out of the question.

looks like i will will be needing to get my mps claibrated soon with teh new 96 mm motor getting built for me.

a wide band O2 sendor seems like a nice way to adjust it by.

i may end up doing this too.

i have mapped four mps untis. me and a friend had using a vacuum pump, gage and a henry meter, each was different, some strikingly so.

the thing is we never tested it otehr than by seat of the pants, so that got me thinking of an O2 sendor, i used on on a triumph for tunning a carb, tricky but doable, it should be fun with the multible screws to turn on the MPS !!!

any advice on which screw does what and so forth when adjsuting?

I recommend Brad Anders articles on the D-Jet at http://members.rennlist.com/pbanders/manif...sure_sensor.htm

That will tell you which screws to turn and so forth. There are other adjustments outside of the MPS though-

- fuel pressure. It MAY be interesting to try a regulator that is modulated by manifold vacuum. I'm curious if it'd be possible to use a diaphram-less MPS that is properly set up with such a regulator. That'd be a great way to solve the diaphram availability and reliability issue! Later applications did exactly that- Mercedes and Cosworth-Vega (OMG!) to name two.
- ballast resistor value.
- timing- definitely affects vacuum, and anything that affects vacuum affects MPS and therefore AFR with D-Jet

Some or all of these are documented in other threads by others here at 914world.

As far as MPS is concerned, the mapping I've done with each of these various diaphrams evaluates the range that they can be set within, by pre-biasing the diaphram towards or away from the coil to max limits of the adjustment. As you can see, the pristine stock diaphram has a very w-i-d-e range available. I'm hoping to see where within that wide range is best for my engine.

When I get my data logger running, I should have a visual tool to see what's going on across the range of vacuum the engine sees, and I can try these ideas, one variable at a time...

Click to view attachment

diaphram-less MPS that is properly set up with such a regulator.this sounds too easy.i hope that someone has success with this idea

Yes. I've just read this front to back and it's interesting as hell. But, can anyone tell me why salt makes the ice colder when making ice cream!

I'm also thankful we have a community of scientific types to do this work. It's on the track of keeping our cars on the road. Original parts are getting too $$$ out of hand from mfg's like Bosch. THANKS First Class Work.

if you are running a stock rebuild motor setting the MPS via a Wavetek is the easiest way and works. We have the known settings for the Wavetek to do this.
if you are running a non stock cam you must adjust the inner and outer screws for the proper AFR and slope, then set the WOT stop screw for the WOT AFR (12.5 to one). Using a LM1 hooked up properly doing multiple runs is the only way I know how to do this. On a roller dyno or on the road works fine.