Cascade Crew

alloy · Posted: Mon Oct 08, 2007 4:03 pm Post subject: No knock retard

I've noticed some pinging lately, so I hooked up my Autoxray on the way home from work today. I get knock counts, but no timing retard. Just reads zero. The knock sensor is obviously working to get knock counts, but I'm not sure where to start looking for why the computer isn't retarding the spark. And yes, it does go into closed loop mode.

Any ideas?

Sellmanb · Member Joined: 30 Nov 2004 Posts: 727 Location: Tigard, OR

How bad of knock is it? I am not sure the formula, but the ECM wont kick back timing unless it sees so many knock counts in a certain time period. This is incase there's false knock (i.e. going over big bumps or bumpidy roads can create false knock)

alloy · Posted: Mon Oct 08, 2007 5:10 pm Post subject:

Well in a very short period of time I had 120 knock counts. I've looked at this before with the scanner when it was working properly and there was definately spark advance being pulled out. Something quit working, not sure what.

Sellmanb · Member Joined: 30 Nov 2004 Posts: 727 Location: Tigard, OR

well, the knock sensor sends it's signal to the ESC module, which gets spark control info from the PCM. Check the ESC