Part Throttle UTEC Issues

JonnyC · 06-24-2008, 03:35 PM

I'm sure the answer is buried in a big thread somewhere, but here goes...

When rolling back onto the throttle (~%5 throttle maybe?) while decelerating, the UTEC dumps fuel. AFR is around 11 while I continue to be very light on the throttle. Because of this, when I roll back onto the throttle slowly, there's a nice noticeable drop in power for a split second. It's really more annoying than anything, and probably wreaks behind me when I'm feathering the throttle going down a hill.

Is this a common issue with the UTEC? Can it be fixed at all?

gothchick · 06-24-2008, 06:56 PM

Sure it can be fixed... Just do some data logging, and adjust your 20% and 30% load columns to run a little leaner at that specific rpm range. I wouldn't mess with the 10% column running leaner, otherwise you may get some shift knock.

Curious, are you MAF tuned or MAP tuned?

JonnyC · 06-24-2008, 08:07 PM

Thanks gothchick - but I should have stated - I'm running MAP based since I have the Vortech. Cruising around town I stay in the 0% column the entire time - which means I'm piggy back. AFR is good at every RPM in the 0% column, except for this situation where I'm slightly on the throttle. So it can't be adjusted through the 0% column.

I'm thinking the only thing I can do is get my ecu flashed to scale my 650 injectors - since it seems like the UTEC isn't actually piggybacking at the point of slightly being on the throttle. I'll have to log the adjusted MAF voltage and see what's going on.

gothchick · 06-25-2008, 02:50 PM

Yeah, if you're having the problem in closed loop (before UTEC transistions to open loop), then you'll have to get the ECU flashed/ scaled for the upgraded injectors. Until UTEC tranistions to open loop, it doesn't even know about the upgraded injectors because it's all ECU at that point...

06-24-2008, 03:35 PM	#1
JonnyC Registered User Join Date: Oct 2005 Location: WI Posts: 1,369 iTrader: (15)	Part Throttle UTEC Issues I'm sure the answer is buried in a big thread somewhere, but here goes... When rolling back onto the throttle (~%5 throttle maybe?) while decelerating, the UTEC dumps fuel. AFR is around 11 while I continue to be very light on the throttle. Because of this, when I roll back onto the throttle slowly, there's a nice noticeable drop in power for a split second. It's really more annoying than anything, and probably wreaks behind me when I'm feathering the throttle going down a hill. Is this a common issue with the UTEC? Can it be fixed at all? __________________ STS...and loving it www.wisconsinzcrew.com

06-24-2008, 06:56 PM	#2
gothchick LivingDeadGirl Join Date: Feb 2007 Location: ATL Posts: 3,297 iTrader: (12)	Sure it can be fixed... Just do some data logging, and adjust your 20% and 30% load columns to run a little leaner at that specific rpm range. I wouldn't mess with the 10% column running leaner, otherwise you may get some shift knock. Curious, are you MAF tuned or MAP tuned? __________________ 2006 6MT GT Silverstone, Nismo floormats - Coming soon: Nismo license plate frame Last edited by gothchick; 06-24-2008 at 06:58 PM.

06-24-2008, 08:07 PM	#3
JonnyC Registered User Join Date: Oct 2005 Location: WI Posts: 1,369 iTrader: (15)	Thanks gothchick - but I should have stated - I'm running MAP based since I have the Vortech. Cruising around town I stay in the 0% column the entire time - which means I'm piggy back. AFR is good at every RPM in the 0% column, except for this situation where I'm slightly on the throttle. So it can't be adjusted through the 0% column. I'm thinking the only thing I can do is get my ecu flashed to scale my 650 injectors - since it seems like the UTEC isn't actually piggybacking at the point of slightly being on the throttle. I'll have to log the adjusted MAF voltage and see what's going on. __________________ STS...and loving it www.wisconsinzcrew.com

06-25-2008, 02:50 PM	#4
gothchick LivingDeadGirl Join Date: Feb 2007 Location: ATL Posts: 3,297 iTrader: (12)	Yeah, if you're having the problem in closed loop (before UTEC transistions to open loop), then you'll have to get the ECU flashed/ scaled for the upgraded injectors. Until UTEC tranistions to open loop, it doesn't even know about the upgraded injectors because it's all ECU at that point... __________________ 2006 6MT GT Silverstone, Nismo floormats - Coming soon: Nismo license plate frame Last edited by gothchick; 06-25-2008 at 02:54 PM.