2000 Chevy Silverado project "Charlie Murphy"
03-25-2016, 09:08 AM
#481
Do you have a wideband hooked up and logging correctly? How do you have the AFR Error math set up?
I usually keep LTFTs off permanently and let the STFTs do the work. If more than 25% fueling correction is needed (limits of the STFTs) then something major is off. Mine is usually within 4% or so, so no need to worry. Idealy it would be zero but that never happens in the real world, within 5% is pretty good.
I usually keep LTFTs off permanently and let the STFTs do the work. If more than 25% fueling correction is needed (limits of the STFTs) then something major is off. Mine is usually within 4% or so, so no need to worry. Idealy it would be zero but that never happens in the real world, within 5% is pretty good.
03-25-2016, 03:08 PM
#482
Do you have a wideband hooked up and logging correctly? How do you have the AFR Error math set up?
I usually keep LTFTs off permanently and let the STFTs do the work. If more than 25% fueling correction is needed (limits of the STFTs) then something major is off. Mine is usually within 4% or so, so no need to worry. Idealy it would be zero but that never happens in the real world, within 5% is pretty good.
I usually keep LTFTs off permanently and let the STFTs do the work. If more than 25% fueling correction is needed (limits of the STFTs) then something major is off. Mine is usually within 4% or so, so no need to worry. Idealy it would be zero but that never happens in the real world, within 5% is pretty good.
VCM Scanner V3 How-To / Getting Started Threads
I added the analog NKG AFX wideband to the “Channels” list on the left. In the “Chart vs Time” graph on the right, it’s in white, second box down, labeled AFR.
Honestly, me being me, I'd rather put in the math manually, but I guess all that math is built in now. I'm sure there is a way to do it manually still, but I just don't know enough about it.
03-25-2016, 04:19 PM
#483
I guess my next thing is injectors. Can I, or should I, install injectors without upgrading the fuel pump? What is the outcome of running 60lb injectors on a stock fuel pump, with a stock engine? Well, stock LQ4 with the exception of the z06 camshaft.
I bought my injectors several years ago. Here’s the original for sale thread:
Original thread:
https://www.performancetrucks.net/fo...prings-497897/
I believe the site that they were purchased from no longer exists. I think it was corvetteinjectors.com. I think this is a link to the new site:
https://secure.fuelinjectorconnectio...-set-of-8.html
I believe this is the injector description I saved from when I purchased them in 2012.
These are brand new Flow Matched set of 8 Bosch EVI4 injectors
These are brand new Bosch EVI4 injectors
60 lb Bosch EV14 High Impedance
Genuine Bosch High Impedance Injectors
These injectors flow 60 lbs/hr at 43.5 PSI ( 3 BAR ) and more at higher PSI. In addition, these units are high-impedance. Despite the high flow rate, they are linear and controllable at low pulse widths and have been used in ULEV applications! This allows you to use a larger injector than normally possible without hurting idle and low speed driveability. Adding to the flexibility of application, these units are high-impedance; making them compatible with most ECUs, while delivering the most flow available in a High-Impedance injector. These injectors represent the most current Bosch engineering and are used on many high power oem applications.
These injectors are able to function at high fuel pressures and don’t exhibit the high fuel pressure handling problems found with many other high flow high-impedance injectors. Many tuners push these injectors to 6 bar and higher.
Engine performance and running quality are enhanced through the optimized spray pattern. Unlike competitors “pencil stream” high flow injectors; these High Flow injectors utilize a multi-orifice tip for improved mixture preparation and atomization. This results in lower BSFC and better idle quality than many injectors with less flow.
Features:
Genuine, reliable Bosch Injectors
Excellent response characteristics
Robust Design
High Impedance
Low Impedance performance characteristics with High Impedance Compatibility
Specifications: Coil Resistance: 12 Ohms (This high-impedance injector will work with all factory ECM/PCM injector drivers)
Spray Pattern: Wide Split Cone, (6 orifice)
Electrical Connector: USCAR (New-style V=EV6 / Oval / LS2)
I also have an excel sheet that I have from FIC when I ordered the pigtail adapters way back when.
Here’s the sheet:
https://www.dropbox.com/s/ht3476hi8q...v_00.xlsx?dl=0
So looking at that sheet, it says on the first page that I need to multiply everything by 1.1547 for 58 psi ratings. For the LQ4, should I use the tables listed in the LS1-LS6-LS2 page?
Then, on the first page it says this:
**If you are using a FUEL PRESSURE REGULATOR that is manifold referenced, please populate the ENTIRE table(s) with the FIRST column of data in RED. If you do not understand, please ask us.
Does this apply to me using the factory fuel pressure regulator? Or is this something else?
I bought my injectors several years ago. Here’s the original for sale thread:
Original thread:
https://www.performancetrucks.net/fo...prings-497897/
I believe the site that they were purchased from no longer exists. I think it was corvetteinjectors.com. I think this is a link to the new site:
https://secure.fuelinjectorconnectio...-set-of-8.html
I believe this is the injector description I saved from when I purchased them in 2012.
Originally Posted by fuelinjectorconnection.com
These are brand new Flow Matched set of 8 Bosch EVI4 injectors
These are brand new Bosch EVI4 injectors
60 lb Bosch EV14 High Impedance
Genuine Bosch High Impedance Injectors
These injectors flow 60 lbs/hr at 43.5 PSI ( 3 BAR ) and more at higher PSI. In addition, these units are high-impedance. Despite the high flow rate, they are linear and controllable at low pulse widths and have been used in ULEV applications! This allows you to use a larger injector than normally possible without hurting idle and low speed driveability. Adding to the flexibility of application, these units are high-impedance; making them compatible with most ECUs, while delivering the most flow available in a High-Impedance injector. These injectors represent the most current Bosch engineering and are used on many high power oem applications.
These injectors are able to function at high fuel pressures and don’t exhibit the high fuel pressure handling problems found with many other high flow high-impedance injectors. Many tuners push these injectors to 6 bar and higher.
Engine performance and running quality are enhanced through the optimized spray pattern. Unlike competitors “pencil stream” high flow injectors; these High Flow injectors utilize a multi-orifice tip for improved mixture preparation and atomization. This results in lower BSFC and better idle quality than many injectors with less flow.
Features:
Genuine, reliable Bosch Injectors
Excellent response characteristics
Robust Design
High Impedance
Low Impedance performance characteristics with High Impedance Compatibility
Specifications: Coil Resistance: 12 Ohms (This high-impedance injector will work with all factory ECM/PCM injector drivers)
Spray Pattern: Wide Split Cone, (6 orifice)
Electrical Connector: USCAR (New-style V=EV6 / Oval / LS2)
Here’s the sheet:
https://www.dropbox.com/s/ht3476hi8q...v_00.xlsx?dl=0
So looking at that sheet, it says on the first page that I need to multiply everything by 1.1547 for 58 psi ratings. For the LQ4, should I use the tables listed in the LS1-LS6-LS2 page?
Then, on the first page it says this:
**If you are using a FUEL PRESSURE REGULATOR that is manifold referenced, please populate the ENTIRE table(s) with the FIRST column of data in RED. If you do not understand, please ask us.
Does this apply to me using the factory fuel pressure regulator? Or is this something else?
03-25-2016, 05:32 PM
#484
If you have a referenced regulator (99-03) then yes thats you, use the first value for the whole table. Big injectors will support more power on the stock pump, but a better pump is obviously needed at some point. Even a walbro255 with 60s will support around 600 or so.
03-26-2016, 03:45 PM
#487
I decided to install my 0-100 psi fuel pressure gauge. I bought it second hand years ago. I bought an adapter off of eBay to install the pressure sender on the fuel rail. Where else would you guys install a fuel pressure sender? The fuel rail seems like a good spot, but if theres a better one, please let me know.
After experimenting with tuning, it was clear that I need larger injectors. I decided to go ahead an install the fuel pressure gauge and injectors at the same time. I know I'll need to install a larger fuel pump as well, but right now I'm hoping I'm fine since the LQ4 is essentially stock with a cam.
Prior to this I had tapped the fuel rail test port to supply fuel to my nitrous solenoid. Also, I ordered a cap for when I remove the nitrous setup and go turbo. I figured that was easier than trying to install the factory schrader valve.
One thing I didn’t know was that my replacement 60lb injectors are taller than my factory injectors.
The taller injectors are a different plug style. Way back when, I was going to splice the correct connector plug, but have since decided that adapter pigtails were way easier. Ended up costing me $50 if I remember correctly.
Taller injectors means taller fuel rail.
After experimenting with a bunch of washers, I finally found a combination that matched the gap made by the taller injectors.
Using the excel spreadsheet from the previous post and a lot of googling, I started changing the tune for the larger injectors. The first thing I did was change IFR vs KPA VAC to 83.211 (Multiplied 72.020 by 1.1547 per FIC spreadsheet). Then I checked the IFR modifier vs Battery Voltage. The tuning sheet said to change to 1.0, but the table was already 1.0.
Heres where thing started getting weird. The excel sheet said to change the Short Pulse Limit to 2.5ms. My factory tune was at 3.997ms but when I changed it to 2.5, hptuners corrected it to 2.492ms.
For the Short Pulse Adder Table, I tried to copy/paste the values from the excel spreadsheet, but hptuners wont do it. When I copy the entire table over, the software changes all the numbers. It wont even let me manually change the values beyond a certain point. Just to be clear, the table is modified, but not to the exact numbers from the tuning sheet. Hptuners corrected every single value in the table and I don't know why.
Changed the Minimum Injector Pulsewidth to 0.125 and hptuners corrected it to 0.122.
Changed Default Injector Pulse changed to 0.125 and hptuners corrected to 0.122
Injector Offset vs Battery Voltage vs KPA VAC I copied the red column the spreadsheet to the first column in hptuners. Then I multiplied by 1.1547. Next, I copied the higher values over to every column in the table.
Factory fuel pressure is supposed to be 58 psi right? After modifying the tune for the 60lb injectors, it fired right up! I’m not sure if this is normal, but it looks like my fuel pressure is around 50 psi at idle and bumps up to 58 psi under load.
Tune for 60lb injectors.
https://www.dropbox.com/s/lv558u6aqp...ctors.hpt?dl=0
First drive with 60lb injectors.
https://www.dropbox.com/s/7a6mm7bb6m...ctors.hpl?dl=0
I had planned on driving it home, but the tune is so out of whack, that I decided otherwise. The LTFTs are at 25% and the log is reporting knock at half throttle. Also, theres a weird dead spot when accelerating from a stop and the engine almost dies. It feels like it's going lean just off of idle.
I figure this is normal injector swap tuning issues. Thanks for all the help guys!
After experimenting with tuning, it was clear that I need larger injectors. I decided to go ahead an install the fuel pressure gauge and injectors at the same time. I know I'll need to install a larger fuel pump as well, but right now I'm hoping I'm fine since the LQ4 is essentially stock with a cam.
Prior to this I had tapped the fuel rail test port to supply fuel to my nitrous solenoid. Also, I ordered a cap for when I remove the nitrous setup and go turbo. I figured that was easier than trying to install the factory schrader valve.
One thing I didn’t know was that my replacement 60lb injectors are taller than my factory injectors.
The taller injectors are a different plug style. Way back when, I was going to splice the correct connector plug, but have since decided that adapter pigtails were way easier. Ended up costing me $50 if I remember correctly.
Taller injectors means taller fuel rail.
After experimenting with a bunch of washers, I finally found a combination that matched the gap made by the taller injectors.
Using the excel spreadsheet from the previous post and a lot of googling, I started changing the tune for the larger injectors. The first thing I did was change IFR vs KPA VAC to 83.211 (Multiplied 72.020 by 1.1547 per FIC spreadsheet). Then I checked the IFR modifier vs Battery Voltage. The tuning sheet said to change to 1.0, but the table was already 1.0.
Heres where thing started getting weird. The excel sheet said to change the Short Pulse Limit to 2.5ms. My factory tune was at 3.997ms but when I changed it to 2.5, hptuners corrected it to 2.492ms.
For the Short Pulse Adder Table, I tried to copy/paste the values from the excel spreadsheet, but hptuners wont do it. When I copy the entire table over, the software changes all the numbers. It wont even let me manually change the values beyond a certain point. Just to be clear, the table is modified, but not to the exact numbers from the tuning sheet. Hptuners corrected every single value in the table and I don't know why.
Changed the Minimum Injector Pulsewidth to 0.125 and hptuners corrected it to 0.122.
Changed Default Injector Pulse changed to 0.125 and hptuners corrected to 0.122
Injector Offset vs Battery Voltage vs KPA VAC I copied the red column the spreadsheet to the first column in hptuners. Then I multiplied by 1.1547. Next, I copied the higher values over to every column in the table.
Factory fuel pressure is supposed to be 58 psi right? After modifying the tune for the 60lb injectors, it fired right up! I’m not sure if this is normal, but it looks like my fuel pressure is around 50 psi at idle and bumps up to 58 psi under load.
Tune for 60lb injectors.
https://www.dropbox.com/s/lv558u6aqp...ctors.hpt?dl=0
First drive with 60lb injectors.
https://www.dropbox.com/s/7a6mm7bb6m...ctors.hpl?dl=0
I had planned on driving it home, but the tune is so out of whack, that I decided otherwise. The LTFTs are at 25% and the log is reporting knock at half throttle. Also, theres a weird dead spot when accelerating from a stop and the engine almost dies. It feels like it's going lean just off of idle.
I figure this is normal injector swap tuning issues. Thanks for all the help guys!
03-26-2016, 04:27 PM
#489
LTFT's at 25% is high, but is it + or - LTFT's? If they're positive you're 25% too rich. Too rich of an air/fuel mixture can cause the knock sensors to go crazy, probably the same if you're 25% lean. I believe the last truck I tuned was a 99 or 2000 and it picked up knock when it was too rich. Apparently that particular operation system (OS) was really bad for picking up false knock from what I remember.
Chances are you will have to retune the VE slightly after swapping injectors.
Chances are you will have to retune the VE slightly after swapping injectors.
03-26-2016, 05:41 PM
#490
LTFT's at 25% is high, but is it + or - LTFT's? If they're positive you're 25% too rich. Too rich of an air/fuel mixture can cause the knock sensors to go crazy, probably the same if you're 25% lean. I believe the last truck I tuned was a 99 or 2000 and it picked up knock when it was too rich. Apparently that particular operation system (OS) was really bad for picking up false knock from what I remember.
Chances are you will have to retune the VE slightly after swapping injectors.
Chances are you will have to retune the VE slightly after swapping injectors.
The LTFT are +25%. If my operating system is prone to false knock reporting, is there anyway I can correct for it in the tune, or update to a newer/better OS? Or is it a limitation of the ECU itself?
Also, I reset the fuel trims before logging and installed new knock sensors when I swapped the LQ4 in.
Thanks for tips guys!