How to Test 1980 KZ1000G Classic Computer ECU

Need to know if there is anyway to test the ECU computer off the bike if it is good or not. Any help would be appreciated.

Not simply with a meter.

You can bench test it with a good coil and a battery and some wire. I can give details if needed.
I will eventually draw up a test diagram for bench testing for actual spark.

This link shows how to make one from HEI parts.
home.comcast.net/~loudgpz/GPZweb/Ignition/GPZgmHEImod.html

instant bookmark of loudhvx link ! thanks

yet... thats for the igniter... i believe Z Parts is trying to test the computer under the seat. For the G classic i think will be kind of impossible unless you can get the signals from all the EFI sensors.

in the past I have found some jonke owners and G classic owners that said they tested the computer by plugging it to a fullyworking bike but i cant belive that because:

1) never seen together 2 of the few EFI working in the world
2) I would never let any one put anything in my classic (that sounds odd)
3) i would never lend my working ECU

do the basics as if it were a car, test it on your bike. it's it a no spark, no fuel, our none of either?

do you have power? proper ground? at the ecu.

Oops, sorry, didn't realize he meant the computer for EFI. :blush:

Maybe put noid lights on your injectors to see if they are getting a signal?

Yes they can be tested. I sent me ECU to ..Bettabikes.. in Adelade.. Australia. They fixed it and sent it back. When I pluged it in the bike fired up and ran like new...So they can be checked and repaired, its just a case of finding the right person.

I've looked through the factory service manual plus later updates: it shows multimeter diagnostics and wiring diagrams of all the component parts but makes no mention of testing the ecu. Pre OBD ecu's on old cars can sometimes communicate by blink codes but I don't think this is an option here.

I guess it is a case of working through all the interconnecting component tests and if everything is ok the only solution is a suspect ecu.

that's how we did it in the automotive world. You would follow the trouble shooting tree diagram and if you made it through all of the component tests without finding a fault the last step was almost always “replace ecu"

I asked the OP if there was spark, or fuel, our neither because that can help determine were to start checking...

A lot of 'ECU faults' are an external wiring or sensor fault, assuming it is an EFI fault that is. Saying that, so many EFI bikes got changed to CV34 or other carbs over the years, I guess the ECU maybe not a massively sought after part.

Off topic, but some old Jap analouge electronic music gear I have is 1980's vintage and still works perfectly. So I think the quality of build was so much better for electronics in those days, and the old stuff lasts longer than the new.

If I get another kawi 1100 i'd like it wiith original EFI., so ahead of it's time then.

If you go to the 750turbo site there is/was some info there on repairing the 750 Turbo computer, and I suspect the Classic computer is probably simpler.

www.edlinecycle.com has these ECU's and other FI parts now and then.