Will a MSP for a 1.7 run a 2.0 Options

[TonyA]

Will a MPS on a 1.7 run a 2.0

[JeffBowlsby]

Thanks James, I think I understand. Many of those early PNs in your list seem to be now-obsolete PNs, but I would need to research older sources...I'll trust their accuracy.

I have a 1998 Bosch parts book and it indicates only the three MPS PNs we now know and love...049 for all 1.7s, 037 for the 73 2.0, and 043 for the 74-76 2.0. It also indicates the 049 MPS for the 1970-73 VW 411.

We know that Bosch updates their parts lists over time droipping off obsolete PNs, and its no surprise that my 1998 book des not indicate the earlier PNs, it only lists the superseded PNs current in 1998.

All is good.

[JamesM]

Thanks James, I think I understand. Many of those early PNs in your list seem to be now-obsolete PNs, but I would need to research older sources...I'll trust their accuracy.

I have a 1998 Bosch parts book and it indicates only the three MPS PNs we now know and love...049 for all 1.7s, 037 for the 73 2.0, and 043 for the 74-76 2.0. It also indicates the 049 MPS for the 1970-73 VW 411.

We know that Bosch updates their parts lists over time droipping off obsolete PNs, and its no surprise that my 1998 book des not indicate the earlier PNs, it only lists the superseded PNs current in 1998.

All is good.

Bosch/VW part numbers always seem to have some cloud of mystery around them.

I believe the three PNs in your Bosch book will work for the applications they assoicate them with now but they were not necessarily the original parts shipped on the cars. While this might lead one to assume that the listed numbers were the superseded final part numbers there is an issue with that as well, specifically there is a 0280100044 variant of the 03906051 (VW) part for the 2.0s and a 050 version of the 049 1.7 sensor as well which leads me to believe the 043 and 049 versions were not the final version of the part for those applications.

While I don't know all the specific differences between the parts (and cant remember all the ones I did know) I have mapped the inductance curve of every one that crossed my path, as well as dissembled a good deal of them. While I did see difference in the curves of all the parts in the same "family" its unknown if they were intentional or just a result of time so its hard to say if there were any tuning changes made across the parts run or if the differences were only internal, but they all did scope out slightly differently.

The 049 1.7 sensor only came about 73 and I suspect its existence may have been related to the change in casting of the housing that the 2.0 sensors required. The 049 sensors use the same casting as the 2.0 sensors and can be converted to work with a 2.0 fairly easily where as the earlier 1.7 sensors require modification of the housing to allow for the travel necessary to calibrate them for a 2.0.


Long story short, I have never seen a single parts book that gave the whole picture, or even that didn't have omissions or just outright wrong information. Maybe a contributing factor to why people struggle getting d-jet running correctly without jacking with their MPS or tweaking the resistance of their CHT circuit, neither of which should be necessary or at least I have never found it necessary on my multiple d-jet cars that still pass emissions tests.