I tuned my cousins Evo a month ago. The car has 3" TBE, ARC air box, Power Enterprise boost controller/gauge, and the UTEC. The car was running awesome, 24 psi on 92 octane, no knock, timing was 12-13 degrees in the torque peak and went up to 20 at redline.

Then two days ago out of nowhere, the power is gone and the car bucks violently under boost. Boost is still the same, there are no boost/vacuum leaks, plugs are in good condition and gapped at .028, a/f is still the same as it was before.

The only thing that has changed is the timing. I didn't change the timing, and nobody else has touched the car. I did a log today and the timing goes up and down (7,5,8,6,10,8....etc) at wot as soon as boost hits, and it does this to about 6500 rpms. It acts like the ecu is pulling timing, but there is no knock in the datalogs. I compared before and after datalogs and everything is the same except the timing.

For some reason I cant post the datalogs on here from my laptop. So if anybody has any suggestions without actually looking at a log, it would be greatly appreciated.

 

12-13 at peak torque!!!!! wow that is too much! peak should be around 9 at the highest on pump gas. your boost is also pretty high for 92 octane. What are your AFR's? Also your knock sensor could be junk but the way you discribe it sounds like the car is pulling timing...bring the boost down to 21-22 and the timing down to 6-9 degrees at peak torque and ramp to 19-20 degrees from there. Also what does the fuel map look like? Stock Injectors? Can you post a Log?

 

24psi on 92 octane, 12-13* timing at spike and 20* at redline I guarantee is pulling timing. It is likely that your knock voltage or sensor is not hooked up correctly.

What a/f ratio is it tuned for?

I am guessing at multiple issues including a tune that is too aggressive, boost leak and knock sensor issue.

 

Keep us posted I would like to hear the outcome. Maybe a batch of bad gas and the car is pulling timing???????