I have never been able to get a knock senors reading. I even tapped on the block with a hammer to simulate it but no luck. Has anyone using Freescan have knock show up on there laptop?

 

I've been using freescan for years on my 94. Are you looking for an increase in "knock count" or "knock retard"?

I had a bad tank of gas earlier this year and was getting bad knock under any kind of load... Freescan showed as much as 14 degrees knock retard and knock count went up every time I stepped on the gas or went up a hill...

 

The knock count is useless i think. It will show 3864 on one drive and 330 the next. It doesn't keep a current count so it does me no good. There is also a knock one that should keep a current reading on the knock but mine has never read anything but zero. The knock retard will read 18-22 usual and 40+ on deceleration.

 

You say you have "knock retard" of 18-22 (I'll assume that's at idle), and at times this value goes to 40+. I'd suspect what you are looking at is the spark advance, and since it has a "-" sign on it, you are assuming it is "retard", when in fact it is the way spark advance (before TDC) is expressed in some scan programs.

Then you say there is a knock field, that always shows "0". That is the knock retard field, and you want it to show zero. I've reviewed many Freescan logs, and they do correctly show knock retard when it is present.

Knock count is not useless, but it also doesn't track knock sensor performance. It apprears to be a calculated value that simply increments up the value until it hits the max value for the field size, then resets to "0" and starts all over again. It generally increases by a couple thousand counts at every startup.

 

I thought that if you tapped on the block with a hammer it would show up in the scan as knock. Is there any other way to verify this? Is there a code for a bad or disconnected knock sensor? If the wire was burnt or damaged would the computer know? Would it go into limp mode if it didn't work correctly? Sorry for so many questions.