First start, 7060 to 7427 Conversion - Crazy rich at idle

[dave w]

Thank you, Dave. I can do that. But sorry for my ignorance, what will that tell me? Should I expect to see a more stable spark advance if I disable?

Yes, disabling the KNK might provide a more stable spark advance. Possibly indicating the Memcal knock filter circuit is faulty, or PCM is faulty / PCM not faulty.

dave w

[Daveo91]

OK, I have knock retard disabled in the .bin. At least I think I do. I have min temp, RPM, and MPH for knock retard all set at maximum values, and I unchecked the "Set" check box for Code 43. But as soon as start the data stream, engine running or not, the flag sets? Not sure why, I must be doing something wrong in TunerPro? Assuming I actually do have it disabled, I'm still not seeing any change. Lots of fluctuation on spark advance at idle, more than 5 degree swings. But not seeing SES light, not hearing any knock on driving, and advance settles down with any load/throttle.

I'm going to start checking the obvious stuff. Timing, dist cap, rotor, plug wires.

[dave w]

Setting the KNK enable parameters to maximum will normally disable the KNK. Disabling code 43 will normally disable the SES from illuminating if code is set.

It appears from the post above, disabling KNK had no effect on timing swings, so re-enabling KNK is a good plan.

It's normal to see some timing fluctuations of a few degrees at idle with a timing light. More than 5 degrees is outside of the normal range.

Perhaps the Ignition Module is degraded?

dave w

GM Module.jpg

[Daveo91]

Setting the KNK enable parameters to maximum will normally disable the KNK. Disabling code 43 will normally disable the SES from illuminating if code is set.

It appears from the post above, disabling KNK had no effect on timing swings, so re-enabling KNK is a good plan.

It's normal to see some timing fluctuations of a few degrees at idle with a timing light. More than 5 degrees is outside of the normal range.

Perhaps the Ignition Module is degraded?

dave w

Thank you, Dave. I haven't actually checked with a timing light, but I will do that next. It's been quite a while since I've checked timing. I figure while I'm doing that I'll take a look at each plug wire with the light, just to make sure nothing odd going on with a given cylinder.

I am trying to remember when the last time was I replaced the ignition module. I may have a working one still around. If I find it I will put it in to see if that changes anything. Thanks for the tip.