caspers knock gauge problem

[jamier]

hi to all out there I need some help with a small problem. ihave a knock gauge which is installed in my 87 turbo t. the problem is the gauge is not working properly. It's a 3 wire hookup 1 power 2 ground and 3 to the yellow/black off the ecm. I did this as per instructions and the light goes green when the ingition is turned on then goes into the red when cranking and stays there. I have the power plugged into the ignition port in the fuse box. I tried for the hell of it to go into a bat port and the gauge seemed to work fine, problem is it wont shut off that way. I also noticed that before wiring it for the 3rd time today, when the gauge was hooked up ( all 3 wires) it would affect my knock reading on my scanmaster, meaning my scanmaster knock would not work! I unplugged the gauge for the time being until I can find the problem, Any suggestions??? thanks all....

 

[BRAD_PADGETT]

I have the Casper knock gauge as well as the Scanmaster 2 and they do work differently. I would double check your wiring pursuant to the Caspers as well as the Scanmaster instructions. The Caspers and Scanmaster measure different knock info. The Casper knock gauge measures the signal from the knock sensor to the ECM. The Scanmaster measures the ECM response to the knock signal as it adjusts timing. Wired correctly they do not interfere with each other. Good luck- Brad

 

[GNVenom]

You need to place the power positive feed from the gauge to a switched ignition power source, such as a radio feed. It MUST go off during cranking. That will solve your problem.

John

 

[jamier]

thanks for the info

I switched the power and reset my computer as a precaution and the gauge is now working , but ! other small problem my knock detection on the scanmaster is not registering now, any suggestions....