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Posted by: Jason74914 Mar 5 2019, 08:30 PM

1974 1.8L with stock L-Jet Bosch FI

I need to replace or repair my ECU which has the following on the label:
Bosch part # 0-280-000-103
Porsche # 022-906-012-G

I've located a 1974 1.8L donor car (inoperable and history unknown):
It's ECU has a label with:
Bosch part # 0-280-000-111

So, the difference in the Bosch # is last three digits: "103" vs "111"

Also, the donor ECU does not have the Porsche # on the label, but I tried to cross-reference, and I'm coming up with: 022-906-012-B

So, difference in Porsche # is only the last letter: "G" vs. "B"

Interweb shows the "B" associated with a 1975-76 VW Bus or 914.
(I have no idea why the donor car--which is definitely a 1974--has the "111/B" ECU in it.)

Question: Can I replace my "103/G" ECU with the "111/B" ECU?

Thanks,
Jason

Posted by: ClayPerrine Mar 6 2019, 05:56 AM

The L-Jet ECUs will interchange within the same year. But you can't use a 74 ECU on a 75, or a 75 ECU on a 74. The wiring to the air flow meter is different.

Good luck.

Posted by: jim_hoyland Mar 6 2019, 06:58 AM

A quick look at the connectors on the AFM will help:

IIRC, the late AFMs have a 7 pin connector, and the earlier AFMs have a six pin connector.

Posted by: Jason74914 Mar 6 2019, 08:39 AM

Thanks guys!
Sort of what I thought. I do have the chance to grab the AFM off of the donor car as well, so I will just do that, and either way I should have the correct combination of ECU and AFM.
Final question, is the throttle body any different?
Thanks again,
Jason

Posted by: ClayPerrine Mar 6 2019, 09:37 AM

QUOTE(Jason74914 @ Mar 6 2019, 08:39 AM)