Hello,
This started with a problem I had with, what I believe to be a stock 1.7 FI engine.
In a prior thread I diagnosed a FI problem which I thought was caused by a malfunctioning Manifold Pressure Sensor, so I replaced the unit with a tested functioning one. This did not solve the problem. As it turns out the problem was oil on the distributer FI contacts, (I found the repair in the factory repair manuals but discounted it, sometimes I just don't learn).
I left the MPS that I replaced in the car since it was running.
After a few tankfuls of fuel I noticed the mileage was not so great, about 21mpg, although I do push the car hard, I have had much better mileage.
I decided to pull the MPS and put my old one back in, also the sensor was a bit to close to the fuel rail and I wanted to adjust the distance.
Looking at my "original" MPS I was very surprised, the numbers on the body where the "same" and "different" from the PBAnders info on Rennlist!
See the photo below.


Click to view attachment
Anders indicates the the correct MPS for a 1.7 is Bosch # 0 280 100 049 and the VW # 022 906 051E as you can see the unit has the 049 Bosch number above the VW 051 number but the last letter is a C with an X engraved over it and an E engraved to the right of the X'ed out C!

In addition I can say that the unit was tampered with.

Click to view attachment

The rivets have been removed and the body tapped and screws used to hold the unit together. Also the center of the of the epoxy plug has been drilled and resealed, it seems with the same epoxy.

I have owned the car for 29 years, I have replaced a few FI hoses and a rubber boot or two, and leaky fuel injectors, but that is about it.

So the questions I am starting with, was this a "type O" at the Bosch factory and a change in production or is this a remanufactured unit, I suspect the MPS was still available before 1983 and this could have been a hodgepodge of different parts to make a functioning unit?


I will also update this post with any changes in fuel mileage.
Thanks for looking.
Mike

Sorry I should have added this link to the first post.

Mike


http://www.914world.com/bbs2/index.php?sho...=113546&hl=

That MPS was rebuilt at some point in it's life. A rebuilder would have Xed out the "C" and added the "E" after recalibration. Who actually rebuilt the unit would not be known as the sticker they place on it is long gone apparently.

Yep, its been rebuilt and a PO has drilled the WOT stop out to "adjust" it. Who knows what its setting is now but I bet its rather rich as that is what most PO or shadetree shops do to cover fixing vacuum leaks.

Yes I do believe it has been rebuilt, but that still does not account for the number disparity. The VW number 022 906 051C is not associated with the Bosch number 0 280 100 049 both of which are stamped into the upper part of the body.
A rebuilder would not have been able to mix up these numbers.

Thanks for the response but I don't think someone who would do a quickie repair would engrave a new letter into the body of the unit.
And it still does not answer the question of the mixed up numbers on the body of the unit.
VW 022 906 051C is a 2.0 FI part from 1973 only which should carry Bosch part # 0 280 100 037.
A shop could not have mixed these numbers up they are not interchangeable.
Mike

You wouldn't believe what production rebuilders can mix up.

But this could only be done by the original builder Bosch.

Not so ....

Python Injection
Fuel Injection Corporation
Brett Instruments (bought by FI Corp)

and a few more .....................

Oh, BTW, I am a core broker and sell to rebuilders.

A MPS has two body parts so when its put back together you just grab a good cap and reinstall the pieces and go. They used to have a stick on label with the model it was adjusted to.

As its drilled out, it can be set to anything as you can adjust the inner screw by drilling the cap.
To adjust it by ear, have a friend try to hold the rpms at 2500 and then adjust the inner screw to the Best running at the 2500rpms. It will be half assed close but it will run good and worn't be too lean.

I do understand the issues with rebuilding parts but the point is none of these rebuilders can stamp an original Bosch part number into a rebuilt part!
Bosch or VW had to make the original mistake in numbering, as a 051C is not associated with the 049 VW part number.

Please refer to the first picture which shows the VW and Bosch symbols adjacent to their respective part numbers, both numbers are stamped into the same part of the unit.

I see that but I guess the rebuilder put the "C" on it.