Friend has a MEFI 1 that has burned up two engines and we are attempting to see if the knock sensor is working.

We will end up sending the ECU to Tyler (if he's not STILL working on the Joker) to check the fuel curves and pulse width, but would like to test the knock system.

Anyone know if the knock sensor on a MEFI 1 is tied to the ECU or just the timing module?

You referenced pulse width so I assume it's Fuel Injected....I just lost a modified 500EFI due to bad fuel injectors. (just something else for you to check)

On a MEFI 1 the knock module is a seperate component and it's pretty easy to tell if it is working or not. The ECM supplies the knock module with 12 volts. When the knock sensor is not detecting any knock, it sends a 10 volt signal back to the ECM. When it does detect a knock, it removes the 10 volt signal, and the ECM retards the timing. You should be able to monitor the 10 volt circuit and that should tell you when and if it's detecting a knock or not.

Or you could just monitor the Knock Retard with a scan tool. Is it setting a code 43?

Dave

Thanks. No codes though!

I am not sure of your question but here goes. If you are not able to check the voltage as above. You can run the engine above 1800rpm then hit the block near the sensor rapidly with a hammer to simulate a knock and the RPM should fall-off. If you are counting on the knock sensor to protect your engine you may be making a mistake, especially if it has a blower. Mine went off twice that I know of last season however I completely fried a set of pistons prior to the retardation.