TOPIC: 2006 Frontier 4.0 4x4 has been grooved!

2006 Frontier 4.0 4x4 has been grooved! 02 Apr 2020 11:12 #37

  • Ron Hatton
  • Offline
  • Founder
  • Founder
  • Gadgetman
  • Posts: 397
  • Karma: 1081
  • Thank you received: 452
Best is to start with about 5 degrees, and run it out. If that's good, try a couple more...

R.
Ron Hatton
Developer of The Gadgetman Groove
Smile for a stranger today.
You will both be glad you did.
The following user(s) said Thank You: CLAUDIO CORDOVA

Please Log in or Create an account to join the conversation.

2006 Frontier 4.0 4x4 has been grooved! 02 Apr 2020 12:02 #38

  • GregK
  • Offline
  • Explorer
  • Explorer
  • Posts: 1142
  • Karma: 103
  • Thank you received: 558
5 degrees BEFORE or AFTER TDC, Ron? (TracyG?) I was always under the impression that BEFORE was what we want - so the air-fuel charge was just starting to burn and expand as the piston gets to TDC for greatest power.
The following user(s) said Thank You: CLAUDIO CORDOVA

Please Log in or Create an account to join the conversation.

2006 Frontier 4.0 4x4 has been grooved! 02 Apr 2020 12:06 #39

  • Ron Hatton
  • Offline
  • Founder
  • Founder
  • Gadgetman
  • Posts: 397
  • Karma: 1081
  • Thank you received: 452
While the Forums associated with this ride may be reporting advancing the timing, that steals even more of the fuel economy, Greg. I thought you knew that!

You will want to retard it BY about 5 degrees to start with from whatever its current setting is. But we haven't done extensive testing, so play with it! Let's all learn together!
Ron Hatton
Developer of The Gadgetman Groove
Smile for a stranger today.
You will both be glad you did.

Please Log in or Create an account to join the conversation.

2006 Frontier 4.0 4x4 has been grooved! 02 Apr 2020 12:12 #40

  • GregK
  • Offline
  • Explorer
  • Explorer
  • Posts: 1142
  • Karma: 103
  • Thank you received: 558
The truth, I suppose, is that we want to have a base timing somewhere where the engine can advance/retard within the limits of the system it uses do to that...required timing depends on engine demand, and driving style I would guess.

Please Log in or Create an account to join the conversation.

2006 Frontier 4.0 4x4 has been grooved! 02 Apr 2020 17:27 #41

  • Vernon
  • Offline
  • Adventurer
  • Adventurer
  • Posts: 55
  • Karma: 5
  • Thank you received: 14
I disconnected the EFIE and the fuel trims went higher. And the catalyst efficiency code came back. I might try the o2 sensor spacers on the front next

Please Log in or Create an account to join the conversation.

2006 Frontier 4.0 4x4 has been grooved! 03 Apr 2020 09:48 #42

  • neil
  • Offline
  • Adventurer
  • Adventurer
  • Posts: 35
  • Karma: 22
  • Thank you received: 21
Thought I may make some comments here, being referred by Greg.
My comments are not following much knowledge about having success with the groove but I have done lots of similar stuff.
Here goes, please question anything I say that you disagree with or makes no sense.
Firstly any ECU can run a motor with probably only 2 inputs (sensors). These are crank angle and load. These are the "essential" inputs, we can easily verify "essential sensors" by unplugging them with the engine running and the motor will immediately stop. Non essential sensors will not stop the motor when unplugged (but will cause open loop operation and perhaps a code)
Imagine an ECU operating a motor through its outputs, with "programs" when only connected to two inputs (also check 12 volt power supply and good earthing wires, This is called OPEN LOOP and ignores all the other (non-essential) sensors it might be connected to. This is a normal scenario every time we first start a motor because it is impossible for a ECU to immediately be optimizing operations. A lot of people worry about an ECU running permanently in open loop but I have found negligible difference in fuel economy or performance.
Now an ECU operating like this is operating well below its capability; so the ECU monitors all of the non essential sensors and switches to CLOSED LOOP after they have come into a desired RANGE. This is where a faulty sensor can trick the ECU and cause all sorts of problems, any diagnostic procedure should include forcing an ECU back to OPEN LOOP to help isolate the problem. This is as easy as cutting a wire to any non ESSENTIAL sensor.
I explain all this before saying what I have done.
I did fuel economy checks for OPEN and CLOSED loops, in my case there was no difference in fuel consumption, so I have forced OPEN LOOP operation for ease of "adjustments".
After grooving I think there would be 2 things that primarily need to be changed - fuel and timing, comments are below.
ADJUSTING FUEL RATIO- The only simple ways I can do this is to go into OPEN LOOP and adjust the Air flow meter signal to ECU or change the fuel rail pressure. Option 1: the preset program opens the injector for a set time if I reduce the pressure less fuel will go through in that time. This can only work in OPEN LOOP because in CLOSED LOOP the o2 sensor would simply cause the ECU to compensate by opening the injectors longer. Option 2: (I did this one) use a 50,000 ohm variable resistor to reduce the voltage from the air flow meter to the ECU, the ECU then delivers the correct amount of fuel for a lesser amount of air. My variable resistor is mounted on my dash and I can change it whilst driving.
ADJUSTING TIMING- When in OPEN LOOP timing curves are always very safe, many older people have always advanced timing (petrol and diesel) and seen benefits by advancing more than the manufacturers have dared to. The better "PREPARED" an air charge is prior to ignition then the less advance is required. I can best explain this in a story of my following a very clever mans advice to optimise motors running on Propane. I built a hot air box for the intake air and was aiming to having the intake air at hotter than 100 degrees Celsius (212 Fahrenheit), he advised me to dismantle my distributor and remove all advance capabilities, I did this and ran fixed advance of about 5 degrees before TDC (including highway cruising at 3000rpm). This is radically different to standard advance curves that see spark ignition occurring more than 40 degrees before top dead centre. Crazy to think about fuel starting to burn 40 degrees before tdc.
It is my opinion that standard advance curves are way to advanced for successfully Grooved motors.
I have not investigated how to change the input to the ECU to reduce degrees of advance, I am hoping that the ECU will "hear" any detonation and retard timing until it stops detonating. I am confident reducing fuel ratio is the first and most important thing to do. My scan tool shows me the amount of advance, I am now curious and wish I had tried to record degrees of advance in all different circumstances. When I was playing with propane engine ignition advance, it seemed hard to optimise and the benefits were quite small.
Regarding advance- cold motors need more advance and vice-versa. slow RPM requires less advance and Vice-versa. Slow burning fuels need more advance and Vice-versa. Petrol vapor burns much faster than liquid petrol.
Vernon, I would be interested if you have any luck with the o2 sensor extenders, in my last post I explained what I did and saw no change in the o2 sensors output with extender fitted. I guess from my comments above it is obvious I think it is a very complicated way to change the computers fuel delivery and only works after the ECU switches into closed loop.
Being able to see fuel trims is evidence of being in closed loop, Im pretty sure the two trims are showing the short term and long term changes it is making to the ECU's self learning, not left and right banks of the motor. I did not know any scan tool could reduce timing advance, perhaps it is only the closed loop adjustments that you can adjust? I would be even more surprised if it the OPEN LOOP presets that can be changed by a scan tool.
My ECU stays in open loop because I cut one wire on the o2 sensor.
I think this is the easiest way to seek the grooves potential and experiment, I hope to later get it back into closed loop operation.
The following user(s) said Thank You: Tracy Gallaway

Please Log in or Create an account to join the conversation.

2006 Frontier 4.0 4x4 has been grooved! 03 Apr 2020 13:18 #43

  • GregK
  • Offline
  • Explorer
  • Explorer
  • Posts: 1142
  • Karma: 103
  • Thank you received: 558

Vernon wrote: I disconnected the EFIE and the fuel trims went higher. And the catalyst efficiency code came back. I might try the o2 sensor spacers on the front next


I thought the front (upstream) sensor was where extenders were supposed to go in the first place...where did you hear differently?
It's the upstream sensor(s) that get the most computer attention...which is why we put modifier circuitry on them - to trick the computer into thinking it's overdelivering fuel for the given quantity of air... If your EFIE was on the post-cat (downstream, rear) o2 and you were sending the computer a voltage increase to indicate less oxygen was passing through the convertor than it expected - of course you would get a catalyst efficiency code.

Please Log in or Create an account to join the conversation.

2006 Frontier 4.0 4x4 has been grooved! 03 Apr 2020 14:31 #44

  • GregK
  • Offline
  • Explorer
  • Explorer
  • Posts: 1142
  • Karma: 103
  • Thank you received: 558
my replies are in this colour -Greg

neil wrote: Thought I may make some comments here, being referred by Greg.
My comments are not following much knowledge about having success with the groove but I have done lots of similar stuff.
Here goes, please question anything I say that you disagree with or makes no sense.
Firstly any ECU can run a motor with probably only 2 inputs (sensors). These are crank angle and load. These are the "essential" inputs, we can easily verify "essential sensors" by unplugging them with the engine running and the motor will immediately stop. Non essential sensors will not stop the motor when unplugged (but will cause open loop operation and perhaps a code) that's exactly what happens - a code triggers open loop
Imagine an ECU operating a motor through its outputs, with "programs" when only connected to two inputs (also check 12 volt power supply and good earthing wires, This is called OPEN LOOP and ignores all the other (non-essential) sensors it might be connected to. This is a normal scenario every time we first start a motor because it is impossible for a ECU to immediately be optimizing operations. A lot of people worry about an ECU running permanently in open loop but I have found negligible difference in fuel economy or performance. Unplugging a correctly functioning MAF sensor might shut down fuel injectors - the computer has no reference as to the MASS of air getting sucked into the engine, so it can't do the math to reckon fuel injector pulse durations for 14.7:1 - zero air means zero fuel required, right?
Now an ECU operating like this is operating well below its capability; so the ECU monitors all of the non essential sensors and switches to CLOSED LOOP after they have come into a desired RANGE. This is where a faulty sensor can trick the ECU and cause all sorts of problems, any diagnostic procedure should include forcing an ECU back to OPEN LOOP to help isolate the problem. This is as easy as cutting a wire to any non ESSENTIAL sensor. or disconnecting it from the wiring harness
I explain all this before saying what I have done.
I did fuel economy checks for OPEN and CLOSED loops, in my case there was no difference in fuel consumption, so I have forced OPEN LOOP operation for ease of "adjustments".
After grooving I think there would be 2 things that primarily need to be changed - fuel and timing, comments are below.
ADJUSTING FUEL RATIO- The only simple ways I can do this is to go into OPEN LOOP and adjust the Air flow meter signal to ECU or change the fuel rail pressure. Option 1: the preset program opens the injector for a set time if I reduce the pressure less fuel will go through in that time. Actually, I would increase the pressure: if More fuel is sprayed by the injector under higher pressure when it's open, the more likely it is that the o2 sensor feedback will shorten the time that they're open This can only work in OPEN LOOP because in CLOSED LOOP the o2 sensor would simply cause the ECU to compensate by opening the injectors longer. right, that's why you want to boost pressure Option 2: (I did this one) use a 50,000 ohm variable resistor to reduce the voltage from the air flow meter to the ECU, the ECU then delivers the correct amount of fuel for a lesser perceived amount of air making for a higher actual ratio of AIR to fuel...more air for the same amount of fuel . My variable resistor is mounted on my dash and I can change it whilst driving.
ADJUSTING TIMING- When in OPEN LOOP timing curves are always very safe, many older people have always advanced timing (petrol and diesel) and seen benefits by advancing more than the manufacturers have dared to. The better "PREPARED" an air charge is prior to ignition then the less advance is required. I can best explain this in a story of my following a very clever mans advice to optimise motors running on Propane. I built a hot air box for the intake air and was aiming to having the intake air at hotter than 100 degrees Celsius (212 Fahrenheit), he advised me to dismantle my distributor and remove all advance capabilities, I did this and ran fixed advance of about 5 degrees before TDC (including highway cruising at 3000rpm). This is radically different to standard advance curves that see spark ignition occurring more than 40 degrees before top dead centre. Crazy to think about fuel starting to burn 40 degrees before tdc. actually, contrary to popular knowledge/belief, it's not explosions happening in the cylinders, but fairly controlled burns that take time for the combustion event to reach peak pressure and expansion for power/force to move the piston.
You have to light the charge off earlier at higher rotational speeds because that expansion time (flame front speed) is fairly fixed

It is my opinion that standard advance curves are way to advanced for successfully Grooved motors. someone makes the decision about power vs efficiency for the average user. people who choose to modify their car do so to impart their own decisions in the place of that decree from "on high"
I have not investigated how to change the input to the ECU to reduce degrees of advance, I am hoping that the ECU will "hear" any detonation and retard timing until it stops detonating. I am confident reducing fuel ratio is the first and most important thing to do. that's why we're here :)My scan tool shows me the amount of advance, I am now curious and wish I had tried to record degrees of advance in all different circumstances. When I was playing with propane engine ignition advance, it seemed hard to optimise and the benefits were quite small.
Regarding advance- cold motors need more advance and vice-versa. slow RPM requires less advance and Vice-versa. Slow burning fuels need more advance and Vice-versa. Petrol vapor burns much faster than liquid petrol. liquid gasoline/petrol doesn't burn - the fuel injectors atomize it, making it easier for engine vacuum to vaporize more of the smaller droplets. That's why Direct Injection engines have such high fuel pressures
Vernon, I would be interested if you have any luck with the o2 sensor extenders, in my last post I explained what I did and saw no change in the o2 sensors output with extender fitted. I guess from my comments above it is obvious I think it is a very complicated way to change the computers fuel delivery and only works after the ECU switches into closed loop. correct - the engine only listens to the o2 sensors when the coolant temperature sensor determines the engine to be at correct operating temperature
Being able to see fuel trims is evidence of being in closed loop, Im pretty sure the two trims are showing the short term and long term changes it is making to the ECU's self learning, not left and right banks of the motor. it depends on a lot of things - I have a V motor but only one upstream o2 sensor - convention is one on each exhaust manifold IF the computer can control individual injectors well enough I did not know any scan tool could reduce timing advance, perhaps it is only the closed loop adjustments that you can adjust? I would be even more surprised if it the OPEN LOOP presets that can be changed by a scan tool. there is a difference between a scan tool and a programmer tool. certain tuners go so far as to build their own computer and customize the fuel map for that car/driver. base fuel map numbers - for open loop it's the coolant temp; for closed loop - is what the o2 sensors "Trim" in either direction based on air/coolant temp/pressure, knock...
My ECU stays in open loop because I cut one wire on the o2 sensor.
I think this is the easiest way to seek the grooves potential and experiment, I hope to later get it back into closed loop operation.please keep us posted on your findings and progress!


Neil - I suspect in your case on your truck, you may want to look into replacing the fuel filter (if it has one - it could be gummed up, reducing pressure at the injectors) or the pump itself if the pressure spec is outside of factory norms at the rail(s). (One easy way to boost pump pressure is to boost the voltage the pump runs on by a volt or two - there are electronic hacks for that, and I know of one video I could point you to for reference if you want to test that)

Another thing that comes to mind - voltage - what is the alternator putting off vs what it should be? might you need a rebuild to replace a bad rectifier or regulator? or is there a grounding issue? I'd start here before the fuel system stuff I mentioned above. it could be that your alternator operates at 13.5v and the computer needs 14.4 (or the opposite!)...that will travel downstream to computer AND sensors and fuel pump and injectors and and and... Remember: battery voltage is not the same as alternator supply voltage - batteries build up resistance over time - measure from the alternator output red positive and a chassis ground you know/trust. if it's below a voltage that will top the battery off and keep it charged (over 13v in either case), there is your first problem
The following user(s) said Thank You: neil

Please Log in or Create an account to join the conversation.

2006 Frontier 4.0 4x4 has been grooved! 03 Apr 2020 18:43 #45

  • Vernon
  • Offline
  • Adventurer
  • Adventurer
  • Posts: 55
  • Karma: 5
  • Thank you received: 14
The idea of sensor spacers are to move the rear sensor away from the exhaust stream so it cant detect a weak cat. I did put them on the front sensors this evening but it made things go wacky. It tripped codes P0153 P0133 for “slow response” and the short term fuel trims were just moving about wildly. From -4% to 15%

Please Log in or Create an account to join the conversation.

2006 Frontier 4.0 4x4 has been grooved! 03 Apr 2020 18:46 #46

  • Vernon
  • Offline
  • Adventurer
  • Adventurer
  • Posts: 55
  • Karma: 5
  • Thank you received: 14
Me being able to adjust the ignition timing is because the ECM in the truck allows me to do it. Every single volvo I hook the same scan tool to there is no adjustment that can be done in the major computers like ECM and TCM. But there are ones I can do like climate control module (CCM) can adjust damper motor % and seat heater temp, interior light duration, and a few others

Please Log in or Create an account to join the conversation.

Last edit: by Vernon.

2006 Frontier 4.0 4x4 has been grooved! 04 Apr 2020 08:19 #47

  • neil
  • Offline
  • Adventurer
  • Adventurer
  • Posts: 35
  • Karma: 22
  • Thank you received: 21
my replies are in this colour –Greg
my replies in this bold- Neil

neil wrote: Thought I may make some comments here, being referred by Greg.
My comments are not following much knowledge about having success with the groove but I have done lots of similar stuff.
Here goes, please question anything I say that you disagree with or makes no sense.
Firstly any ECU can run a motor with probably only 2 inputs (sensors). These are crank angle and load. These are the "essential" inputs, we can easily verify "essential sensors" by unplugging them with the engine running and the motor will immediately stop. Non essential sensors will not stop the motor when unplugged (but will cause open loop operation and perhaps a code) that's exactly what happens - a code triggers open loop Hmm! A code won’t always cause open loop, I think Vernon is experiencing a code ATM in closed loop because he still has fuel trims active. In open loop there would be no fuel trimming and no crazy stuff for Vernon to deal with. Being in open loop is a very common and normal thing and doesn’t always mean there is anything wrong….just that there is at least 1 sensor not yet in its normal range. I have no fault codes with the o2 sensor being disconnected, if a did get a code I can easily find another way to have the computer stay in open loop, I could get a spare temperature gauge and connect it to the vehicles harness so the computer doesn’t think the engine has warmed up yet, or a spare o2 sensor not installed in the exhaust…and so on. Open loop doesn’t mean there is a code or problem present.
Imagine an ECU operating a motor through its outputs, with "programs" when only connected to two inputs (also check 12 volt power supply and good earthing wires, This is called OPEN LOOP and ignores all the other (non-essential) sensors it might be connected to. This is a normal scenario every time we first start a motor because it is impossible for a ECU to immediately be optimizing operations. A lot of people worry about an ECU running permanently in open loop but I have found negligible difference in fuel economy or performance. Unplugging a correctly functioning MAF sensor might shut down fuel injectors - the computer has no reference as to the MASS of air getting sucked into the engine, so it can't do the math to reckon fuel injector pulse durations for 14.7:1 - zero air means zero fuel required, right? Yes agreed. One exception is that some engines have two sensors to give engine load, one can be manifold pressure (MAP) and the other can be air flow measuring (MAF).
Now an ECU operating like this is operating well below its capability; so the ECU monitors all of the non essential sensors and switches to CLOSED LOOP after they have come into a desired RANGE. This is where a faulty sensor can trick the ECU and cause all sorts of problems, any diagnostic procedure should include forcing an ECU back to OPEN LOOP to help isolate the problem. This is as easy as cutting a wire to any non ESSENTIAL sensor. or disconnecting it from the wiring harness Yes, but as stated best if it is done in a way that does not result in a code.
I explain all this before saying what I have done.
I did fuel economy checks for OPEN and CLOSED loops, in my case there was no difference in fuel consumption, so I have forced OPEN LOOP operation for ease of "adjustments".
After grooving I think there would be 2 things that primarily need to be changed - fuel and timing, comments are below.
ADJUSTING FUEL RATIO- The only simple ways I can do this is to go into OPEN LOOP and adjust the Air flow meter signal to ECU or change the fuel rail pressure. Option 1: the preset program opens the injector for a set time if I reduce the pressure less fuel will go through in that time. Actually, I would increase the pressure: if More fuel is sprayed by the injector under higher pressure when it's open, the more likely it is that the o2 sensor feedback will shorten the time that they're open Yes I like the idea of higher fuel pressure but in open loop it will over-fuel and in closed loop the oxygen sensor will still cause the same amount of fuel to be delivered, so apart from slightly better atomisation I don’t see any benefit of higher fuel pressure being likely in seeking economy. This can only work in OPEN LOOP because in CLOSED LOOP the o2 sensor would simply cause the ECU to compensate by opening the injectors longer. right, that's why you want to boost pressure I still think this will only lead to more fuel being used Option 2: (I did this one) use a 50,000 ohm variable resistor to reduce the voltage from the air flow meter to the ECU, the ECU then delivers the correct amount of fuel for a lesser perceived amount of air making for a higher actual ratio of AIR to fuel...more air for the same amount of fuel Yes, so it is leaning out the motor. My variable resistor is mounted on my dash and I can change it whilst driving.
ADJUSTING TIMING- When in OPEN LOOP timing curves are always very safe, many older people have always advanced timing (petrol and diesel) and seen benefits by advancing more than the manufacturers have dared to. The better "PREPARED" an air charge is prior to ignition then the less advance is required. I can best explain this in a story of my following a very clever mans advice to optimise motors running on Propane. I built a hot air box for the intake air and was aiming to having the intake air at hotter than 100 degrees Celsius (212 Fahrenheit), he advised me to dismantle my distributor and remove all advance capabilities, I did this and ran fixed advance of about 5 degrees before TDC (including highway cruising at 3000rpm). This is radically different to standard advance curves that see spark ignition occurring more than 40 degrees before top dead centre. Crazy to think about fuel starting to burn 40 degrees before tdc. actually, contrary to popular knowledge/belief, it's not explosions happening in the cylinders, but fairly controlled burns that take time for the combustion event to reach peak pressure and expansion for power/force to move the piston.
You have to light the charge off earlier at higher rotational speeds because that expansion time (flame front speed) is fairly fixed
Yes, agreed, but really any explosion is a controlled burn, even gun powder comes with specific burn speeds for different applications. I think that flame front speed is actually very variable and I suspect that the groove causes a much faster flame front speed/explosion which is why a lot less ignition advance would be my guess
It is my opinion that standard advance curves are way to advanced for successfully Grooved motors. someone makes the decision about power vs efficiency for the average user. people who choose to modify their car do so to impart their own decisions in the place of that decree from "on high" I am not sure if power needs to vs efficiency, i like to think the best power comes at the same time as best efficiency, in any case I am only trying to go the next step to see the groove do something amazing on my vehicle
I have not investigated how to change the input to the ECU to reduce degrees of advance, I am hoping that the ECU will "hear" any detonation and retard timing until it stops detonating. I am confident reducing fuel ratio is the first and most important thing to do. that's why we're here Well I am happy to cut the fuel but I had hoped that the groove would have done this for me, I hoped that a better burn would have caused me to lift the accelerator pedal and fuel would have been saved automatically, I still wonder if I have something else that prevents my groove from doing what I hoped for My scan tool shows me the amount of advance, I am now curious and wish I had tried to record degrees of advance in all different circumstances. When I was playing with propane engine ignition advance, it seemed hard to optimise and the benefits were quite small.
Regarding advance- cold motors need more advance and vice-versa. slow RPM requires less advance and Vice-versa. Slow burning fuels need more advance and Vice-versa. Petrol vapor burns much faster than liquid petrol. liquid gasoline/petrol doesn't burn - the fuel injectors atomize it, making it easier for engine vacuum to vaporize more of the smaller droplets. That's why Direct Injection engines have such high fuel pressures. Yes I agree but liquid fuel is still what goes in! The vaporising process you describe just becomes part of the process, takes time and why earlier ignition is required with liquid fuel having more stuff to do before it can burn.
Vernon, I would be interested if you have any luck with the o2 sensor extenders, in my last post I explained what I did and saw no change in the o2 sensors output with extender fitted. I guess from my comments above it is obvious I think it is a very complicated way to change the computers fuel delivery and only works after the ECU switches into closed loop. correct - the engine only listens to the o2 sensors when the coolant temperature sensor determines the engine to be at correct operating temperature Yes, but to be more clear the engine must be at the right temperature AND in closed loop, there are other reasons why it must not be in closed loop even with correct engine temp
Being able to see fuel trims is evidence of being in closed loop, Im pretty sure the two trims are showing the short term and long term changes it is making to the ECU's self learning, not left and right banks of the motor. it depends on a lot of things - I have a V motor but only one upstream o2 sensor - convention is one on each exhaust manifold IF the computer can control individual injectors well enoughIf there is two sets of trims these are what change the self learning and there are short term and long term self learnt adjustments, I did not know any scan tool could reduce timing advance, perhaps it is only the closed loop adjustments that you can adjust? I would be even more surprised if it the OPEN LOOP presets that can be changed by a scan tool. there is a difference between a scan tool and a programmer tool. certain tuners go so far as to build their own computer and customize the fuel map for that car/driver. base fuel map numbers - for open loop it's the coolant temp; for closed loop - is what the o2 sensors "Trim" in either direction based on air/coolant temp/pressure, knock...Hmm! Open loop needs no inputs apart from crank position and engine load MAF or MAP. Closed loop uses all the sensors, more specifically it does not use any sensor/s until all are in a desired range, I just want to be clear that in open loop there is no adjusting or input from coolant sensors and in closed loop the computer uses all inputs and if it can't then it reverts back to open loop.
My ECU stays in open loop because I cut one wire on the o2 sensor.
I think this is the easiest way to seek the grooves potential and experiment, I hope to later get it back into closed loop operation.please keep us posted on your findings and progress! I will do but with this corona virus we are in lockdown so longer trips are gonna be a while

Neil - I suspect in your case on your truck, you may want to look into replacing the fuel filter (if it has one - it could be gummed up, reducing pressure at the injectors) or the pump itself if the pressure spec is outside of factory norms at the rail(s). (One easy way to boost pump pressure is to boost the voltage the pump runs on by a volt or two - there are electronic hacks for that, and I know of one video I could point you to for reference if you want to test that) Yes could you please point me to that video? I tested my fuel economy in both closed and open loop and everything behaved perfectly (apart from economy) so I am not sure of how the fuel filter could be causing any problem, even if it does have some restriction

Another thing that comes to mind - voltage - what is the alternator putting off vs what it should be? might you need a rebuild to replace a bad rectifier or regulator? or is there a grounding issue? I'd start here before the fuel system stuff I mentioned above. it could be that your alternator operates at 13.5v and the computer needs 14.4 (or the opposite!)...that will travel downstream to computer AND sensors and fuel pump and injectors and and and... Remember: battery voltage is not the same as alternator supply voltage - batteries build up resistance over time - measure from the alternator output red positive and a chassis ground you know/trust. if it's below a voltage that will top the battery off and keep it charged (over 13v in either case), there is your first problem Again I am curious about how changes to fuel pump voltage can affect anything. Fuel pressure is controlled by the fuel pressure regulator, it is not like a power steering system where relief pressure is rarely seen. Having constant fuel pressure is critical for maunfacturers because it is factored into the ECU programming, changes in fuel pressure would mess up open loop operation hugely when there is no computer feedback. My car uses the same amount of fuel in open loop as it was designed to. I think rather than worrying about fuel pressure accidentally being wrong I would say that causing fuel pressure to be incorrect would take major modification of fuel pump output.

Summary; The reason for this discussion is because some engines are not responding to the groove. Perhaps this is because the computer doesn’t see the benefit of the groove. In open loop the computer just injects a preset/same amount of fuel so that there is no saving. Worse than that the o2 sensor also does not see any benefit either(I thought it should btw) and in closed loop we are still not seeing a benefit to the fuel economy. To run further with this theory requires “lying” to the computer, so we just need to know how to do it easily, safely and reliably. I think doing it through the o2 sensor is difficult, hard to adjust and maybe doesn’t allow an adequate range of adjustment either and can only be done as the computer works to its best capacity in closed loop. I like what I have done forcing mine into open loop and make the fuel adjustable from the dashboard. This discussion is getting quite involved but it is good to be clear and hopefully everybody gains.

Please Log in or Create an account to join the conversation.

2006 Frontier 4.0 4x4 has been grooved! 04 Apr 2020 08:56 #48

  • GregK
  • Offline
  • Explorer
  • Explorer
  • Posts: 1142
  • Karma: 103
  • Thank you received: 558

Vernon wrote: The idea of sensor spacers are to move the rear sensor away from the exhaust stream so it cant detect a weak cat. I did put them on the front sensors this evening but it made things go wacky. It tripped codes P0153 P0133 for “slow response” and the short term fuel trims were just moving about wildly. From -4% to 15%


"weak cat?" the only way it could possibly be not able to do the job it was intended for was if it was being overwhelmed by having TOO MUCH to do. that would mean a ridiculously large amount of unburned fuel in the exhaust, and that would indicate poor combustion/ignition and an upstream o2 that's not connected or working at all.
The spacers get put on the front o2s to create a pool or sinkhole of exhaust to surround and immerse the sensor to make it send a "there's WAY too much fuel here" signal to the computer. It's a creative very astute realization and use of the boundary layer principle in a column of vibrating air.

Trims go crazy when the computer is adjusting to a change. what did they settle out at? (did you use the spark plug spacer method? were both of the spacers drilled out to let the exhaust hit the sensor?) Did you put the EFIE back on/in circuit?

Please Log in or Create an account to join the conversation.

Powered by Kunena Forum