Cool Z

OK here's the problem. My motor used to detonate from 5500 rpm's to 6000 rpm's in 3rd and 4500-6000 rpm's in 4th. So, I went out bought an HPP3 and 160* stat. Installed the fan tuning and stat with water wetter. Now according to auto-tap the pinging is gone for the most part. The thing that I don't understand is I'll make a log running through 3rd and 4th gear. Looking at the log file, there is 0 KR, timing is good (28*) but the engine sounded like it was still detonating in the higher rpm ranges and power was fluctuating as if the PCM was pulling timing and then adding it back but the log file again shows nothing. <img src="images/icons/mad.gif" border="0"> Any ideas????? <img src="images/icons/confused.gif" border="0"> Any and all responses are apprieciated!!!! <img src="images/icons/grin.gif" border="0">

Nine Ball

iTrader: (38)

Are you 100% sure you heard detonation? If you were getting timing pulled by the PCM, it would definitely show up on the Autotap. When you Autotap, do you have more monitoring of useless stuff going on at the same time? The more selections you monitor on Autotap, the less effective its sampling rate becomes. Just put the bare essentials you wish to monitor, and get rid of the rest.

B1S1 O2 sensor
B2S1 O2 sensor
KR
Timing
RPM
Throttle position
Coolant Temp

Those are my baselines. Sometimes I put in LTrims.

Tony

Cool Z

Yeah, I run the same peramiters. It sounds like ping but alittle quieter. I've been wondering if maybe the valve springs have weakend and are allowing some valve float. The car only has 8400 miles and I've heard these springs suck. It only happens in third and forth gear 5500+. Its just like the PCM playing with timing while detnation is occuring but there 0 KR and timing is at 25.5* at 5100 or so and increases to 27.5* from 5500-5800 and then 28* 5800+. 02's are .890. I wish I could figure it out. When on the few occasions it doesn't happen, it runs awesome.