I have a scanmaster and mods in sig along with BRAND NEW opti, 8.5mm wires, plugs, 02 sensors, knock sensor, battery, alternator, and fairly new MSD coil and MSD6A unit.

Once the car has been running for about 5 minutes, I'll start to get around 2-8 degrees of knock retard. My madwolf tune has 80% knock desensitizing AND I have the LT4 KM for what it's worth. I can't really track the problem down. I get no codes, light fluttering from 2000-2800 rpms like a slight miss, and to make things more difficult to track, I just recently did a full OBD I conversion with a 1995 knock sensor and I know my 97 PCM would have thrown a code for a misfire. I'm not used to OBD I diagnostics yet and I know you can't track a miss easily in OBD I. Can anyone help me find out why I get that much retard? After a few WOT runs, the car will see some KR at idle (like 1-4*). Could all that just be valvetrain noise?? I was thinking about doing the 100% desensitizing method from brent's page but I don't know. The only other piece of info I could give you that would help is this: I know my MSD 8.5mm wires are FINE at the header end cause I have OTVC set-up, but I run the wires under the alternator and I know the alternator gets very hot after a while so I think the alternator might be burning the wires. Plus the wires are all bunched together under the alt so I don't know if that is causing the miss either. Any help is greatly appreciated

 

Try race gas first (100 octane or so...) and see if the knock goes away. if it does than it isnt false knock.

 

I ran race gas in mine and it didn't go away, thus being real false knock. I ended up programming it out at wot.

 

Does idle even produce the cylinder pressures/temps necessary to have detonation?? I didn't think so. Sounds whacky and like a definite false knock situation.

 

well, because I now have OBD I, couldn't a misfire be causing some knock retard or timing loss? I know with my OBD II system the car would react horribly if there was a miss. I still think the very hot alternator temps are burning my clustered wires that run squashed underneath it.

 

If your really worried about the plug wires, be sure to check and see if the PS pulley is rubbing against them. When i ran my plus under the alt., i routed the wires up the front of the engine behind the PS pulley and up under the alt. You could be chaffing the wires. i dont think its related to your knock problem, but take a peak at them and see. If you didnt route it that way then don worry about it.