Fuel Trim Readings?

Rangerz · 11-29-2013, 01:02 AM

Let me give some history with what I have done and some of the readings I have gotten.

I installed new FI HFC and TDX the first week in Nov. In my rush to install it I disconnected the battery late in the install and had my son press the brake pedal to clear the ECU. Another thing in the rush to get it on the road to heat cycle the exhaust was I forgot to connect the passenger side MAF plug. I drove it about 500 feet then realized what I had done and connected it with the car running. I should mention that the ECU clearance cleared my trip computer and clock but I retained my radio settings.

I run the torque APP on my phone and have several things being displayed but, want to ask about the Fuel Trim Bank 1 (Short Term) Fuel Bank 2 (Long Term) and the same for Bank 2.

When logging at start up my Short Term bank 1 and 2 would read different. The displayed range fluctuates alot but they were never cycling the same one going up one down or the numbers were 4-5 digits different same for bank 2.

Tonight I installed a stillen Gen 3 and disconnected the battery first thing. This time it cleared everything and the radio settings as well. Just got back from a drive and when my ECU relearned its self the bank 1 and 2 reading are cycling the same and are about 20 digits different. Before at idle speeds they would read 4.something now 27. something then they slowly fall lower but together which looks like what they should be doing. The long term cycle for both I assume are for higher RPM's more throttle etc..

I'm not sure how accurate the torque app is but, I would think on everything that is read from the ECU it should be pretty close.

Does anyone know what the normal cycle numbers are for the Bank 1 & 2 short/long term fuel trim readings should be? I would think they should cycle the same numbers from side to side.

Car feels like it has more torque the horsepower readings are based off of the phone accelerometer and your car profile so I don't throw much stock in those readings.

Thanks

Oh and Huck if you read this thanks for your vid on the stillen install.

visconti · 11-29-2013, 10:44 AM

Quote:

Originally Posted by Rangerz

Let me give some history with what I have done and some of the readings I have gotten.

I installed new FI HFC and TDX the first week in Nov. In my rush to install it I disconnected the battery late in the install and had my son press the brake pedal to clear the ECU. Another thing in the rush to get it on the road to heat cycle the exhaust was I forgot to connect the passenger side MAF plug. I drove it about 500 feet then realized what I had done and connected it with the car running. I should mention that the ECU clearance cleared my trip computer and clock but I retained my radio settings.

I run the torque APP on my phone and have several things being displayed but, want to ask about the Fuel Trim Bank 1 (Short Term) Fuel Bank 2 (Long Term) and the same for Bank 2.

When logging at start up my Short Term bank 1 and 2 would read different. The displayed range fluctuates alot but they were never cycling the same one going up one down or the numbers were 4-5 digits different same for bank 2.

Tonight I installed a stillen Gen 3 and disconnected the battery first thing. This time it cleared everything and the radio settings as well. Just got back from a drive and when my ECU relearned its self the bank 1 and 2 reading are cycling the same and are about 20 digits different. Before at idle speeds they would read 4.something now 27. something then they slowly fall lower but together which looks like what they should be doing. The long term cycle for both I assume are for higher RPM's more throttle etc..

I'm not sure how accurate the torque app is but, I would think on everything that is read from the ECU it should be pretty close.

Does anyone know what the normal cycle numbers are for the Bank 1 & 2 short/long term fuel trim readings should be? I would think they should cycle the same numbers from side to side.

Car feels like it has more torque the horsepower readings are based off of the phone accelerometer and your car profile so I don't throw much stock in those readings.

Thanks

Oh and Huck if you read this thanks for your vid on the stillen install.

Can you give anymore details on the readings you were getting?

Leaks on both the intake or exhaust system can make the fuel trims off bank to bank.

If your seeing more than a 5% difference from bank to bank then you defiantly have some short of issue / leak.

As for how accurate the trq APP is - no idea

John

Rangerz · 11-29-2013, 11:52 AM

I will go ch2ck it again today and get some numbers. I dont think I was 5% out from side to side. I will recheck the connections from the cats just to be safe.

Rangerz · 11-29-2013, 10:12 PM

Got some readings today.

Car at operating temp:

At Idle

Bank 1

Short 4.1 to 8.6
Long .8

Bank 2

Short 4.0 to 10.9
Long 5.5

At 3000 rpm driving I was only able to get the long while driving.

Long 1.6 to 4.7 Long .8 to 7.0

Bank 1 short tends to run on average higher than bank 2 short and Bank 2 Long runs higher than bank 1 long. I will get it in the air tomorrow ans check for any exhaust leaks I guess. Although the above readings are measured in % so they would be within 5% even though the highs and lows maybe more.

Any thoughts? Not knowing how much fluctuation is normal I may be over analyzing it.

11-29-2013, 01:02 AM	#1 (permalink)
Rangerz Enthusiast Member Join Date: Jun 2013 Location: Northern Utah Age: 58 Posts: 476 Drives: 2012 370 Nismo Rep Power: 11	Fuel Trim Readings? Let me give some history with what I have done and some of the readings I have gotten. I installed new FI HFC and TDX the first week in Nov. In my rush to install it I disconnected the battery late in the install and had my son press the brake pedal to clear the ECU. Another thing in the rush to get it on the road to heat cycle the exhaust was I forgot to connect the passenger side MAF plug. I drove it about 500 feet then realized what I had done and connected it with the car running. I should mention that the ECU clearance cleared my trip computer and clock but I retained my radio settings. I run the torque APP on my phone and have several things being displayed but, want to ask about the Fuel Trim Bank 1 (Short Term) Fuel Bank 2 (Long Term) and the same for Bank 2. When logging at start up my Short Term bank 1 and 2 would read different. The displayed range fluctuates alot but they were never cycling the same one going up one down or the numbers were 4-5 digits different same for bank 2. Tonight I installed a stillen Gen 3 and disconnected the battery first thing. This time it cleared everything and the radio settings as well. Just got back from a drive and when my ECU relearned its self the bank 1 and 2 reading are cycling the same and are about 20 digits different. Before at idle speeds they would read 4.something now 27. something then they slowly fall lower but together which looks like what they should be doing. The long term cycle for both I assume are for higher RPM's more throttle etc.. I'm not sure how accurate the torque app is but, I would think on everything that is read from the ECU it should be pretty close. Does anyone know what the normal cycle numbers are for the Bank 1 & 2 short/long term fuel trim readings should be? I would think they should cycle the same numbers from side to side. Car feels like it has more torque the horsepower readings are based off of the phone accelerometer and your car profile so I don't throw much stock in those readings. Thanks Oh and Huck if you read this thanks for your vid on the stillen install. __________________ Stillen Gen III/ NST/ Fast Intentions Non-Res HFC & 12" Resonated CF TDX/ Setreb series 9 OC/ SPL upper control arms/ Whiteline front & rear swaybars/ Uprev tuned by Seb@specialtyZ/ 319HP 262TQ/ Z1 PS Cooler/ Z1 SS Premium break lines/ CJM Road Race pump/Carbotech F:XP10 R:XP8 Nismo OC DIY Last edited by Rangerz; 11-29-2013 at 01:05 AM.

11-29-2013, 11:52 AM	#3 (permalink)
Rangerz Enthusiast Member Join Date: Jun 2013 Location: Northern Utah Age: 58 Posts: 476 Drives: 2012 370 Nismo Rep Power: 11	I will go ch2ck it again today and get some numbers. I dont think I was 5% out from side to side. I will recheck the connections from the cats just to be safe. __________________ Stillen Gen III/ NST/ Fast Intentions Non-Res HFC & 12" Resonated CF TDX/ Setreb series 9 OC/ SPL upper control arms/ Whiteline front & rear swaybars/ Uprev tuned by Seb@specialtyZ/ 319HP 262TQ/ Z1 PS Cooler/ Z1 SS Premium break lines/ CJM Road Race pump/Carbotech F:XP10 R:XP8 Nismo OC DIY

11-29-2013, 10:12 PM	#4 (permalink)
Rangerz Enthusiast Member Join Date: Jun 2013 Location: Northern Utah Age: 58 Posts: 476 Drives: 2012 370 Nismo Rep Power: 11	Got some readings today. Car at operating temp: At Idle Bank 1 Short 4.1 to 8.6 Long .8 Bank 2 Short 4.0 to 10.9 Long 5.5 At 3000 rpm driving I was only able to get the long while driving. Long 1.6 to 4.7 Long .8 to 7.0 Bank 1 short tends to run on average higher than bank 2 short and Bank 2 Long runs higher than bank 1 long. I will get it in the air tomorrow ans check for any exhaust leaks I guess. Although the above readings are measured in % so they would be within 5% even though the highs and lows maybe more. Any thoughts? Not knowing how much fluctuation is normal I may be over analyzing it. __________________ Stillen Gen III/ NST/ Fast Intentions Non-Res HFC & 12" Resonated CF TDX/ Setreb series 9 OC/ SPL upper control arms/ Whiteline front & rear swaybars/ Uprev tuned by Seb@specialtyZ/ 319HP 262TQ/ Z1 PS Cooler/ Z1 SS Premium break lines/ CJM Road Race pump/Carbotech F:XP10 R:XP8 Nismo OC DIY

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
False TPMS readings?	winnre	Wheels & Tires	16	01-28-2014 11:03 AM
Skewed Outside Temp Readings	Kenny	Exterior & Interior	9	11-15-2011 07:52 AM
AFR Readings w/o Tune ... Safe?!?	omg35s	Tuning	4	07-22-2011 12:34 AM
50-75% improved fuel economy news story... 'supercritical fuel inejctors'	travisjb	Engine & Drivetrain	4	05-21-2010 11:54 AM
Fuel Filler Tube Coating Flaking Off Into Fuel Tank	SoCal 370Z	Nissan 370Z General Discussions	12	02-02-2010 10:37 AM