finally the place for the new ,,mps,,

[albert]

finally i have find the place who can rebuilt the ,,mps,,bosh,, for appx,,150.$ depend the model,, i d,t know now for the 412 but they remain the type3 model,,311-906-051 E,, i have send ,,email ,,and i am waything,, more news more lather,,albert

[albert]

sorry ,, i was too lathe ,,all the manifold sensor 051 was sale excepted 3 for the type 3,, but i have open 5 différent mps, and they are différent inside ,,the 2 coils inside are différent ,, plus the diaphram ,, and the aneroil cells are différent with diférent pn and différent expention,, the ,,,0280-100-019 or vw 022-906-051 is good only for porsche 914-1.7 and the 411 69-70 the résistance on the contact 7-15 is 84 ohm,,and contact 8-10 is 325 ohm,,,,,,,,the 022-906-051A or 0280-100-019 is good for porsche 914-1.7 1970 and the 412 -72 and the résistance on the contact no.7-15 is 82 ohms,,and the contact 8and10 315 ohms,,the model 022-906-051 B or 0280-100-027 is for the type3 but can fit for type4 -71 ,, the contact 7-15 is 93 and contact 8-10 is 93-350 the aneroil inside is stamp no.49, the same no. is stamp on the 2 coil frame inside ,,,the 022-906-051 C is good for the porsche 914-2 litre 73 the contact 7-15 is 93 and contact 8-10 is 339 ohms the aneroil is stamp no.62 same no. on the coil,,frame and the most interressant for me the 022-906-051 E i have open 2 like that,,, the résistance 7-15 was 91 and contact 8-10 résistance 345 ohms,for this 2 051 E ,the aneroil was stamp no.60 for one and 53 for the secon ,,,i d,t know wy,,, all this mps was never open ,, the diaphram was identik ( but broken ) on the model 51 E and identik for 51a-b-c ,, and différent with the E the back cover was différent inside too,, the check valve inside the cover are the same but for the spring ??? for the big spring insiide i d,t know or i d,t can see the différence ,,they look all the same ,, for the diaphram on the 051 E as 4 bent in the copper foil and on the oder model only 3 bent ,, and for to restore my 2 ,,051 E ,,i use the 2 oder diaphram in the 051 A,, AND B,,,FOR TO PUT IN MY 051 E ,, the résistance on the contact 8-10 and 7-15 can change with your local altitude ,with the aneroil réaction ,, not many but 3-4-5 ohms différence ,i d,t know for now what performance that can geeve ,, i well see in 4-5 weeks on the road test,,albert

[Lars S]

Yes, there are lot of MPS models with smaller and larger differances to choose from...why should things be easy...

Regarding the resistance at terminal 7/15 and 8/10 the litterature specifies (for all MPS models?) that it should be around 90 and 350 Ohm respectively, possibly the variations registred only are from tolerance in making.
I made at test on five MPS's, all showed a bit lower resistance than the nominal values.
http://www.lsmteknik.se/MPS%20071229b.htm

The resistance should not change due to altitude or manifold pressure but the impedance (measured in Henry) does.

Lars S

[albert]

yes ,,LARS,S ,, wend the mps is open and if we test the 2 coils ,,they geeve appx. the same résistance ,,like you said ,, 90-300,, but wend they are close , the screw for adjustment and the ,,, aneroil cells,, inside ,can play with the altitude with her expention,, plus they moove with the car vaccum action,and with the différent ,,aneroil cells,,, for each différent ,,mps,, we obtain a différent résistance for each ,,,mps,, and if we test again the résistance in ,,ohm,, afther the restoration we have a différent reading,,on my 2 ,,051 E ,, if i test only the coil ,,that geeve me 91-345,, and afther restoration with original,,aneroil cells,, that geeve me 97-355 with the aneroil cells no. 53 for one and 95-351 with the aneroil cells no. 60 ,( ORIGINAL ANEROIL WY THEY ARE DIFFÉRENT ????), and for the 51 C the aneroil cells, no. was 62 and the reading was 93-351,, and i have repeete the same test for the same 051E with 5 différent ,,aneroil cells,, and that geeve me 5 différent reading ,, now you can see the complexitys of this ,,mps,,plus in that we have 2 possibility for the vaccum leak,,, by the broken diaframg and the check valve on the suction tube , and for sure the bad seal on the cover,,albert

[Lars S]

Albert, trying to understand why the resistance (Ohm) changes, cause to me the Ohms in the coil should not be affected by the movment of the armature.
When you shift the aneroid cells do you then re-solder the coils also?

Lars S

[albert]

yes lars,s for one 051 E yes i have re-solder the 4 wires,, but i have test the 2 mps afther the re-solding beefore to close and they was the samething,,same reading ,,91-345 but my vue is the électro madgnétic plonger inside of the coil and the crazy ,,aneroil cells ,, can geeve a kind of électromadgnétic action anf afther ,that can change the reading on the testor,,suspence ??? ,,albert

[albert]

oh yes one more thing,, if we poush on the shat in the midle of the 2 coil ,, we obtain a différent reading on the testor ,, that play with the plonger moovement,,up and down,, albert

[Lars S]

Yes, d u r i n g movement of the shaft you should see a difference in Ohm reading because of the iron armature is inducing a voltage in the coil which affects the Ohm-meter.
The Ohm reading should however be the same for all positions of the shaft as soon as it is stopped.


Lars S

[albert]

yes lars,s you have reason,, with that we can see the électric réaction wend it is in opération on the car,,but one question is not clear for me, wy the résistance change wend we close the cover ,, 91-342 open and 94-345 with all the parts inside,and close ,,, i will see the réaction wend they are on the car,, in opération,,albert

[Lars S]

The temperature difference is the reason for the variation in Ohms.
I heated one of my MPS's up to possibly 80C, the resistance rised from 91 to 110 Ohms witch well fits the temperature coefficient of copper: about 4%.
Glad we got that one!


Lars S

[albert]

thanks ,,lars,s very good thing to know,, yes if we test the coil just afther the re-soldering job that change the calibration,, plus i have see some more information for the ,, aneroild cell,s,, one side is made with the,,,, beryllium,, and the oder side is made with cupper,,now i know wy they are so expensive ,2 différent expention ,,in the hot weather or cold weather,,,albert

[Lars S]

The coefficient for copper is 0,4% excuse not 4%.

More general info on the MPS sensor principle can be read at:
http://en.wikipedia.org/wiki/LVDT

...and its external links.


Lars S

[raygreenwood]

Its worth it to remember...that there are no rebuilt sensors that bench test out to a specific engine #. I have found very few MPS's...that cannot be tuned to fit most any engine. I can take an E-series from 412 and tune to fit a 914 2.0.
Yes...there were some differences in how thinsg wer built....but as long as the MPS has teh adjusting capacity...it can be adjusted. Ray

[albert]

hy,,LARS,S ,, i have some fresh nows for you,, hey,, we have a curious thing,, you see if i test this 3 ,,mps on couple days ,, the résistance change with the humidity in the weather,, for this week,, wednesday night ,, 6 hrs pm,, dryed weather ,, on one,, 051 E,, 91-350,, yestherday same hrs,, rayning time ,, 091- .348,, and tooday wet snow,, .090-.342,,, i have the same ohm différence on my 3 oders ,,mps,, 051 E and o51 C,, now geeve me the reason,, i thing the aneroid make that,, électro madgnétic induction,,, oh ,,they are complet,, and close,,, albert

[Lars S]

Albert,
I believe the difference you notice is from difference in temperature. Each degree Celcius in temperature difference changes the 350 Ohm winding by 1,4 Ohm. Going from 350 Ohms tom 348 is only one to two C in temperature change. The 350 Ohm winding is affected more than the 90Ohm one by temperature change, since the change is in percent.

The inductance differences in the coils, which is changed by the intake pressure moving the iron shaft (inside the coils), can only be measured with a Henry-meter. The D-jet electronic box uses the inductance varaitions not the Ohm variations.

Lars S