well today i was doing a bit of tidying around the engine bay and i found a plug at the back of the engine unplugged with black tape covering up something so on further inspection a found a resister connected to the knock senser and it was not connected to the harness for the ecu so if it was still unplugged the sensor would be doing nothing so would i be right and say the resister should be on the ecu side....

would there be a kit for an after market knock senser to be fitted somewhere handernthan stripping half the engine to replace

 

 

cheers trev

det sensor bypass with a 1megaohm resistor, should be on the ecu side/harness. to tell the ecu that the knock sensor is working. ive had mine in as long as ive had the car, never caused any issues.

have you done an ecu fault code check?

no mate just looking how to do a fault code test... would this give a bad reading on the emissons because the car is going for the mot

http://www.300zx.co.uk/forums/showthread.php?128845-Ecu-diagnostics

ive had no issues for the past 3 mots, with it on. but it may highlight why the sensor is shagged, O2 sensors dead, ecu temp switch etc.

do a test and see what it throws up.

ok done a ecu test

code 34

code 13

 

fingers crossed tomorro

Code 13 is Engine coolant Temp sensor, broken wire/sensor etc..

Code 34 is DET sensor. You will get this as the resistor is on the wrong part of the harness as you said.

 

HTH

ok changed the resister and plugged all up again with the knock senser plugged into the ecu again with the resister as well still showing the same codes so back to square one will have to get a new resister and see if that helps the joys

 

cheers trev

ok changed the resister and plugged all up again with the knock senser plugged into the ecu again with the resister as well still showing the same codes so back to square one will have to get a new resister and see if that helps the joys

 

cheers trev

 

Did you reset the ECU before you tested again?

yes mate should i plug the senser in again or leave it disconnected

It's worth a go. Can't hurt.

You'll be running in safety boost mate if it's throwing those codes up, you'll be chuffed when you sort it and you start boosting properly :-) A 1 Megohm resister in the ECU side of the loom and probably a clean up of the temp sensor connections (front top hard water pipe, 2 sensors on it, one for ECU water temp, other for dash water temp gauge), if you clean up the connections on these, and sometimes you may need to flatten the rivet on the sensor to gain a better connection, and an ECU reset, you should hopefully get yourself out of safety mode, makes quite a difference!