[maherdan82]

I have an 05 Scion Tc with the Turbonetics kit running off the unichip. My problem is every once in awhile driving at low rpm (cruising speed) my car will cut out. It will cut out for a second and come right back. It feels like the unichip is messing with the signal to the drive by wire system. When this happens it feels like the throttle plate is slamming shut and opening back up. The kit is 100% stock on stock settings and everything is installed per Turbonetics instruction manual. Other than this problem the car runs great. Also took the unichip out and the problem went away. Stayed out of boost of course. So who else has had this problem and what was the fix? New unichip? Warranty issue???

[Robert]

Originally Posted by maherdan82

I have an 05 Scion Tc with the Turbonetics kit running off the unichip. My problem is every once in awhile driving at low rpm (cruising speed) my car will cut out. It will cut out for a second and come right back. It feels like the unichip is messing with the signal to the drive by wire system. When this happens it feels like the throttle plate is slamming shut and opening back up. The kit is 100% stock on stock settings and everything is installed per Turbonetics instruction manual. Other than this problem the car runs great. Also took the unichip out and the problem went away. Stayed out of boost of course. So who else has had this problem and what was the fix? New unichip? Warranty issue???

This might seem like a dumb question but are you sure you put the O2 extender on the right sensor? I've seen this happen when the O2 extender was put on the primary instead of the secondary

[maherdan82]

Ya the o2 extender is on the second sensor. Everything was installed correctly.

[Robert]

You could certainly try replacing the Unichip yes. I'm wondering what your fuel pressure looks like at low RPM and what your Fuel Trim is showing from the ECU. Do you have a wideband? Is the car going rich at those loads?

[maherdan82]

i have yet to hook up a wide band so i have no idea. it does not happen all the time. only once in awhile.

[Robert]

Originally Posted by maherdan82

i have yet to hook up a wide band so i have no idea. it does not happen all the time. only once in awhile.

Yeah I'm just wondering if the Short Term Fuel Trim is going super rich and causing the car to cut out

[maherdan82]

Why would that happen? I thought the uni-chip piggy back only made fuel adjustments at WOT when the computer goes into open loop. Otherwise the stock pcm should be making the adjustments at partial throttle in closed loop.

[Robert]

Originally Posted by maherdan82

Why would that happen? I thought the uni-chip piggy back only made fuel adjustments at WOT when the computer goes into open loop. Otherwise the stock pcm should be making the adjustments at partial throttle in closed loop.

No the unichip has to map all the load points to account for the larger injectors. Your PCM is going to try to pull fuel based on the stock injectors not the 630cc injectors you have now

[maherdan82]

so if I am indeed running super rich at low rpm and that is causing the engine to cut that would still be a uni-chip issue correct?

[Robert]

Originally Posted by maherdan82

so if I am indeed running super rich at low rpm and that is causing the engine to cut that would still be a uni-chip issue correct?

It's possible yes.