Question and Log Included

[Ec0tec]

I've been wondering for the longest why my car doesn't nail 103 or so on kpas in boost. I have a 2002 sunfire with the m62 blower on 8 psi. Whenever I enter boost the highest kpa amount I see is around 97-100. I'm thinking maybe a tiny vacuum leak somewhere? I've included a log as well for reference.



Now the second part of my question is, in the log towards the end you see a spurt of knock about 1 degree or so. The afrs see right and so does the Timing. Should I consider that engine noise or look further into it.

Thanks for everyones help.


Attachment 9725

[Russ K]

As your log shows, your only at 83 % TPS at the most. Scan the Map Kpa at WOT. With a 1 bar map, the most you will see is 105 kpa. As far as your spark knock, the histogram shows a max of 1.1*. This is normal and nothing to worry about.

Russ Kemp

[Ec0tec]

Im assuming since my throttle cable is a little iffy I guess if I fix that ill see 105 kpa.

[Ec0tec]

I attached a new log. This is what I was logging and ran into before. Ive even seen spurts of 2.2 at a time but no way near consistent. Just want to make sure everything is ok. Also I do hit 100% tps in this log and still don't nail 105..

[Russ K]

It is very hard to look at a 60 min scan log. When scanning, do a WOT 1-2-3 run, then save & post this scan log. I saw 96% TPS,
but it ended at 4500 rpm.

Did you install a one or two heat range colder spark plugs? Is there a 160* thermostat available? Lower engine temps make a big
difference in spark knock.

Russ Kemp

[Ec0tec]

they are the gm iridiums I believe they are 1 step? not to sure.

also Not sure about the thermostat question. I'm just making sure Im good and its not detonating. I had crazy amounts of my previous tune/log and destroyed the 2nd piston on my old motor. It appears to be burst knock since its not consistent at all and the afr + timing tables are good.