im hoping someone can answer this for me, are the ecu,s on a 1973 2.0 the same unit as on a 1974 2.0 , can i swap one for the other are are there differences?

There were quite a few different ones as the years went by but now only maybe two one for the 73-74 and the other for the 75-76. Actually any 914 1.7 or 2.0 control unit will interchange. The injection systems are so old now that the subtleties really do not make any difference.

http://members.rennlist.com/pbanders/DJetParts.htm

IIRC there were different ECUs & many other EFI system parts between 73 & 74 2.0s - for example the 017 CHT, many of which do make a difference & will drive you crazy trying to run down odd little running issues.

Use the Porsche 914 PET parts catalog at this link to get the proper part no., using the model & year application info. in the right cols.:
http://www.porsche.com/all/media/pdf/origi...USA_KATALOG.pdf

If you have a proper part no. core ECU for yours (double check in the PET at link above, cuz the PO could've changed it, & save the pdf on your computer for future ref.), then Pelican also offers a rebuild service by Fuel Injection Corp./BRET in Calif., at this link:
http://www.pelicanparts.com/catalog/shopca...j_pg2.htm#item9

73 2L -
http://www.pelicanparts.com/cgi-bin/smart/...73%29%2C%20Each

74 2L -
http://www.pelicanparts.com/cgi-bin/smart/...74%29%2C%20Each

Not sure which you have - 73 or 74 & if the wrong one is in your 914 from POs - then get a proper part # core from someone on here to get rebuilt. IMHO you're better off sticking with the proper one, despite what George said.

PS that link to EFI info that detox gave you above is an excellent resource!

Huge difference between a 73 2.0l and a 74 2.0L George! No, they won't interchange other than they will plug in.
A 73 2.0l uses a 037 ECU (same as a 1.7L), a 017 CHT (if you can find one) and a 037 MPS...

A 74 2.0L uses a 044 ECU, 012 CHT and a 043 MPS...
Mixing and matching will result is a barely running 914.

becouse the 73 ecu was used for both the 2.0 and 1.7, it was "scabbed" together to run the newly added 2.0 with a different CHT(017) and an inline resister to trick it to fit the modified needs. i may be wrong but if you use a 74 ecu you will need to match the CHT and MPS. i dont think you'll need anything else... anyone?
check here
http://members.rennlist.com/pbanders/DjetParts.htm

not to hy jack but, why are the 73-74 green 2.0 injectors a different # than green 2.0 75-76?