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914World.com _ 914World Garage _ Pinout values for 74 1.8 ECU

Posted by: L-Jet914 Oct 21 2021, 09:56 PM

I recently bought a used 74 1.8 ECU for a backup part if needed. I was wondering if anyone has any pinout values so I can test the ECU to see if it is good. Thank you in advance.

Posted by: L-Jet914 Oct 24 2021, 04:15 PM

bump

Posted by: timothy_nd28 Oct 25 2021, 10:56 AM

Not sure what you are asking here. Are you asking for resistance values for each ECU pin, or are you using a curve tracer? Either method wouldn't tell you much about the integrity of the ECU.
The fastest way would be a go/no go test by just throwing it into the car and trying it out to see if it works.

To bench test, you would need to bring power and grounds to certain pins. Also find a way to simulate high ignition voltage for the ECU to read, along with a dummy load for the fuel injectors while observing timing of each pulse with a 4 channel O scope. Not to mention providing certain resistances for the AFM and CHT sensor, it would be problematic to bench test the ECU. Pretty sure they have a wheel barrel type test machine that would do this all for you, but again, much easier to throw the spare ECU in the car to see if it works.

Posted by: lesorubcheek Oct 25 2021, 11:22 AM

This is from the workshop manual. Pretty sure the 1.8 was AFC. I'm not a 914 FI guru since ours has carbs. You can find the complete manual for download. No idea if any pins can be tested standalone or not.

Dan

Posted by: StarBear Oct 25 2021, 02:51 PM

Been looking for someone with test equipment for an 1.8 ECU. Someone (Jeff B?) has the 1.7 and 2.0 I think. Special test equipment IIRC.

Posted by: JeffBowlsby Oct 25 2021, 03:10 PM

I have the EFI Associates testers for both MPC and AFC FI systems. Unable to test the ECU by itself, these testers require the ECU in the car with the rest of the FI system, where the testing cable is interposed at the ECU connection with the EFI harness, and the ECU (and the rest of the FI system) is tested in situ. Individual function blocks of the ECU can be verified using this tester in this way.

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Posted by: L-Jet914 Oct 25 2021, 08:47 PM

So I guess quickest way to test the ECU I purchased is to plug it in and see if the car runs?