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SNAFU
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How Things Work: EFI system Glossary of Term

Glossary of Common Terms

BAS – Bank Angle Sensor

This sensor is located in the turn signal module and it sends a signal to the ECM if the bike leans over more than 45° from vertical. If the ECM gets this signal for more than one second it assumes the bike fell over and it shuts down both the fuel management and ignition circuits.

CKP – Crank Position Sensor

This sensor provides input signals to the ECM that indicate engine rpm, (how fast the engine is running in Revolutions Per Minute). The ECM also uses these inputs to determine what stroke the engine is in so it can deliver the fuel and spark at the desired time.

ECM – Electronic Control Module

This is the brain of the system that collects input signals from multiple sensors, makes decisions and sends output signals to deliver fuel and spark to the engine.

Electric Fuel Pump

A 12-volt high-pressure fuel pump, (located in the fuel tank) supplies fuel under pressure to the fuel injectors

ET – Engine Temperature

This sensor provides input signals to the ECM as it reacts to the temperature of the front cylinder head of Softails and Touring model motorcycles. The ECM uses the signals from this sensor to determine if the engine is at operating temperature, or warming up.

Fuel Injectors

The fuel injectors are electric valves that open and close to deliver a high-pressure spray of fuel directly at the intake valve. They are controlled by output signals from the ECM to deliver fuel at a precise moment, (just before the intake valve opens). If more fuel is needed, the ECM will signal the injector to remain open for a longer period of time. The period of time is known as the injector "pulse width" and is measured in milliseconds. One method of rating fuel injectors is by their flow rate – such as in gm/sec, or grams per second.

Fuel Pressure Regulator

A mechanical device that controls fuel pressure to 55-62 PSI by returning excess fuel from the fuel pump back to the fuel tank. The regulator is located inside the fuel tank on Softails and Touring model bikes

IAC – Idle Air Control

An electric valve that’s threaded, (each rotation is a "step") and controlled by output signals from the ECM to open and close as needed to allow enough air into the engine for starting and idle operation. The greater the number of IAC steps, the greater the amount of air enters the engine through the IAC passages.

IAT – Intake Air Temperature

This sensor provides input signals to the ECM as it reacts to the temperature of the air entering the engine. For example, hot air has less oxygen in it than cool air. The ECM uses the inputs from this sensor to help calculate how much oxygen exists in a quantity of air.

Ion Sensing System

This system uses ion-sensing technology to detect detonation or engine misfire in either the front or rear cylinder by monitoring the electrical energy at the spark plug following every timed spark. If an abnormal level of energy is detected across 2 or 3 spark firings the ECM responds by retarding spark timing in the problem cylinder as needed to eliminate it.

MAP - Manifold Absolute Pressure

This sensor provides input signals to the ECM and reacts to intake manifold pressure and ambient barometric pressure. Intake manifold pressure reflects changes in engine speed and load. Ambient barometric pressure reflects changes in atmospheric pressure caused by weather conditions or changes in altitude. The ECM uses the inputs from this sensor to help calculate how much air is entering the engine.

TP – Throttle Position

This sensor provides input signals to the ECM as it reacts to throttle shaft rotation, telling the ECM throttle position, if the throttle is opening or closing, and how fast it’s opening or closing.

VE - Volumetric Efficiency

Volumetric efficiency is a percentage rating of how much air is flowing through the engine while running as compared to its theoretical capacity.

For example, an engine with a displacement of 88-cubic inches running at 5600 rpm at full throttle has a theoretical airflow capacity of 100% when it flows about 143-cubic feet of air per minute, (cfm). If the same engine flows 107cfm at 5600 rpm it would have a VE of about 75%.
If the engine flows about 157cfm at 5600 rpm it would have a VE of about 110%. Note the VE can exceed 100%, especially in high performance engines that have improved airflow through the engine. VE reacts to engine speed and to anything that increases or decreases airflow through the engine.

VSS – Vehicle Speed

This sensor provides input signals to the ECM to indicate if the bike is moving or sitting still. It is used mostly to assist the control of idle speed.
 

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SNAFU
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Discussion Starter #2
How the system works & Race Tuner vs. PCIII!

Overview of the Harley-Davidson ESPFI Electronic Sequential Port Fuel Injection System, (ESPFI)

The ESPFI system is a completely new engine management system used on select 2001 and later Softail models and select 2002 and later Touring models. This system is a speed/density, open loop, sequential port fuel injection design that controls fuel delivery, spark timing, and idle speed.

Look-Up Tables:
Look-up tables contain the information the ECM requires to control engine operation. The ECM uses many different look-up tables to make decisions on fuel and spark management; these are the VE, (Volumetric Efficiency), AFR, (Air Fuel Ratio) and Spark Advance tables.
These look-up tables are stored in the ECM’s internal Flash memory which the Tuning Mode software can change and reprogram.

Volumetric Efficiency (VE):
One look-up table the ECM always uses is Volumetric Efficiency (VE), which is a percentage rating of how much air is flowing through the engine as compared to its theoretical capacity. For example, an engine with a displacement of 88-cubic inches running at 5600 rpm at full throttle has a theoretical airflow capacity of 100% when it flows about 143-cubic feet of air per minute, (cfm). If the same engine flows 107cfm at 5600 rpm it would have a VE of about 75%. And, if the engine flows about 157cfm at 5600 rpm it would have a VE of about 110%. Note the VE can exceed 100%, especially in high performance engines that have improved airflow and tuned intake and exhaust systems. The VE value depends on engine speed and to anything that increases or decreases airflow through the engine. The VE Look-up tables in the Screamin' Eagle calibrations are calculated from data gathered while testing engines on engine and chassis dynamometers, and with track testing on instrumented vehicles.

Air Fuel Ratio:
The ECM also monitors the intake air temperature and manifold absolute pressure, which provide it with an indication of air density, or the amount of oxygen contained in a volume of air.
The AFR, (Air Fuel Ratio) table, which is programmed into the ECM, tells the ECM what AFR the engine should require under specific engine loads, (engine load is determined by monitoring manifold absolute pressure and engine rpm) to produce the performance that’s desired.

Spark Timing:
The front and rear Spark Advance tables tell the ECM the desired spark advance desired for specific engine loads. The actual spark timing used is modified somewhat from the table value based on several operating conditions such as engine temperature, air temperature and fuel quality (octane).

Engine load is determined by monitoring Manifold Absolute Pressure (MAP) and engine rpm.

Operation:

When the engine is running the series of events typically follows the process below:

The ECM monitors the CKP, TP, IAT & MAP sensors telling it engine rpm, throttle position, intake air temperature and manifold absolute pressure.

The ECM looks at throttle position and engine rpm and then refers to the VE Look-up tables to calculate the volume of air that should be entering each cylinder under the present conditions.

At the same time, the ECM looks at intake air temperature and manifold absolute pressure to calculate the density of the air entering the engine. From the Air density and the air volume, the ECM calculates exactly how many grams of oxygen are in the air entering the engine.

Now that the ECM knows exactly how much oxygen is entering each cylinder, it refers to the AFR Look-up table for the AFR that’s desired. From these values, the ECM calculates how much fuel is required and determines what the fuel injector pulse width must be to deliver this fuel. It then sends the appropriate output signals to the fuel injectors to deliver the fuel.

The ECM also refers to the Spark Advance tables for the desired spark advance for each cylinder at the current engine rpm and engine load. The ECM then sends output signals to the front and rear ignition coils to deliver the desired timing of the spark for each cylinder.

Transient Conditions: Start-up
When the engine is experiencing a transient condition it may use additional tables to handle the condition. For example, a cold engine that’s being cranked to start rotates at a very low rpm and needs additional fuel. The ECM reads the ET and CKP sensors, which tell it the engine is cold, and that it’s rotating at cranking speed. The ECM then refers to a Cranking Fuel table and directs the fuel injectors to remain open longer, (by increasing their pulse width) which delivers a richer air/fuel mixture for starting. It also directs the IAC to open to its programmed number of steps to allow enough air into the engine for starting and idling.

When the engine starts to run, the ECM sees the higher rpm and then refers to the Warm-up Enrichment table to add the additional fuel needed while the engine is still cold. The table is designed to diminish its effect to zero as the engine comes up to operating temperature. This is analogous to automatic "choke" operation on a carburetor engine.

Heat Management System
The ESPFI systems on 2002 Touring and Softail series bikes also incorporate a sophisticated heat management system that operates in three phases to keep the engine cool in extreme conditions.
If the ECM detects engine temperature above approximately 300° F while moving or stationary it reduces the idle speed. A lower idle speed produces fewer combustion events per minute and that reduces engine heat.
If the ECM detects an engine temperature that’s still drifting higher while moving or stationary it richens the AFR. An increased amount of fuel in the air/fuel mixture has a cooling effect on the engine.
If the ECM detects an engine temperature that’s still drifting higher while moving or stationary it directs the fuel injectors to skip, (only when the bike is stationary) and not deliver fuel on every intake stroke. This limits the number of combustion events taking place, which produces less heat.
 

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SNAFU
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Discussion Starter #3
Comparison of Race Tuner (RT), Power Commander (PCIII) and Techlusion variants

Note: References made to information in previous posts in this thread​


How the RT, PCIII and TFI (DFO/Race Fueler) differ in operation

To recap, regardless of the method used, the ECM monitors the CKP, TP, IAT & MAP sensors telling it engine rpm, throttle position, intake air temperature and manifold absolute pressure and uses these values in combination with internal tables to calculate fuel delivery and ignition timing.

How the Race Tuner works

The Race tuner is a ECM programming device, it does not remain connected to the bike after the new programs are downloaded into the ECM.

The Race Tuner is used to change the values in the lookup tables that exist in the ECM to make the entire system deliver the proper fuel and spark needed to achieve the performance desired.

With the race tuner you can modify:

Air-Fuel ratio
VE Front Cyl
VE Rear Cyl
Spark Advance Front Cyl
Spark Advance Rear Cyl
Rev Limit
Warmup Enrichment
Cranking Fuel
Idle RPM
IAC Warmup Steps (RPM vs. Temp)
ECM Tuning Constants = Engine Displacement & Fuel Injector Size

If this seems daunting then you're not alone and to remedy this H-D has included a "Basic Mode" that gives you a 2 tables to modify, Air-Fuel Ratio and Ignition Timing. The software will map this information to the more complex tables for you. It's more of a shotgun approach but it's a good way to get "into the ballpark" if you're way off.

Tuning is accomplished by manipulating the table values in the Tuning Mode program and downloading them directly into the ECM.

The Race Tuner also has a Data Capture module that allows you to record data in real time from all these sensors and play it back one increment at a time. This is feature is very useful but can be very tedious if you don't know exactly what you are looking for.

The Race Tuner can modify the rev limiter as well as reset the speedometer to accommodate the 28T pulley upgrade on '02 - '03 bikes. It cannot adjust for variable pulley configurations or chain conversions.

The Race Tuner cannot reprogram the ECM back to it's stock configuration.

The Race Tuner cannot upload (read) the map (program) information loaded in the ECM. It only returns the file information about the program loaded in the ECM. This is why it's critical that you get a copy of the program loaded into your ECM from your tuner.

The Race Tuner can only be used to program one bike, the first one it actually writes a program too. It can read any Delphi equipped Harley


How the Power Commander III works

The Power Commander is a piggy back device. This means it is installed between the ECM and the EFI wiring harness. It remains attached to the bike after installation.

The PCIII DOES NOT modify any of the internal lookup tables. It interprets the data coming into the ECM from the sensors above and manipulates the signals to make the ECM see different readings. At the same time it manipulates the output signals to the fuel injectors and ignition coils to achieve the desired results.

This isn't as easy as it sounds. The PCIII has to do the following to work correctly:

Analyze the incoming signals
Determine the proper fuel and ignition advance required
Determine what signals and values to change
Change it's output signals to the ECM, Injectors and Ignition to achieve the desired result

And do it in a constantly changing environment

I'm not sure the the exact method they use to achieve their results but I'm pretty sure it's a combination reading the ECM inputs and manipulating the signal pulse width to the fuel injectors and delaying or advancing the signal to the ignition coils.

This is all controlled by map files that you or your tuner manipulate and download into the PCIII.

The newer USB version offers an accelerator enrichment function (not really needed on our bikes since that is part of the basic function of the ECM) as well as the ability to modify the front and rear cylinder independently.

The PCIII cannot increase the rev limiter or adjust for the 28T front pulley upgrade on '02 - '03 bikes.

Techlusion Variants (TFI / DFO / Race Fueler / Gill's box)

The Techlusion Variants are piggy back devices but less intrusive than the PCIII. This means it is installed in parallel to the EFI wiring harness. It remains attached to the bike after installation.

These devices can be thought of as "Jet Kits" for EFI controlled bikes. Rather than utilize programmable maps like the PCIII they utilize an enrichment program that's RPM and load dependent, just like the internals of a carburetor. They are relatively easy to hook up but require you to splice into the EFI wiring in 4 places. There are prewired harnesses for most of these that eliminate this need.

RPM, Acceleration, Deceleration and steady state operation is detected and monitored by the device and fuel is added based on internal programming and external trim pot settings. They are very "analog" in their approach to fuel enrichment and seem to work very well for the majority of the users who have simply changed pipes and air filters. The adjustments are typically for fuel enrichment in RPM ranges as well as crossover adjustments to define those ranges. They also offer an accelerator enrichment function (not really needed on our bikes since that is part of the basic function of the ECM)

These devices cannot adjust ignition timing or raise the rev limiter.

I hope this is informational and answers some questions. I'm pretty knowledgeable about the Race Tuner but I have limited exposure to the PCIII and the TFI variants. If I've made any mistakes please let me know.
 

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SNAFU
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Discussion Starter #5
Race Tuner instructions

I have posted the Race Tuner instruction manual for people to read who are thinking about purchasing the Race Tuner. While this is not copyrighted material and is delivered in .PDF format it is not sold as a separate item. Please don't try to sell it on ebay :bash:

UPDATED with V4.7.6 info
 

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SNAFU
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Addendum for close loop (Oxygen Sensor) models:

The Harley closed loop ECM is an extension of the existing Speed Density system with narrow band O2 sensors installed to allow the bike to operate in a closed loop mode under certain conditions. These conditions are primarily partial throttle, low engine load regions where precise fuel metering can significantly improve the bike's exhaust emissions while still retaining good drive ability.

This narrow band system is not able to compensate for engine, exhaust or intake modifications like some aftermarket systems. Being narrow band it only has the capability to tell the ECM whether it's under, at or over the target 14.7:1 air/fuel ratio. A true closed loop system that can adjust for engine changes uses a wide band sensor and can report the precise AFR based on a free air calibration.

Because of this, tuning is still required when pipes are changed or any other modification is made to the engine system. Below is an excerpt from the manual in the previous post explaining how this is accomplished with the newer race tuners.

Tuning with Closed-Loop
Only calibrations that are closed-loop capable can be used for closed-loop operation. When a calibration is opened in Tuning Mode, a box in the upper right region of the screen will indicate if a calibration is intended for open or closed-loop operation.
The AFR table controls the operating conditions in which the ECM will enable closed-loop. The AFR cell must equal 14.6 for the ECM to enable closed-loop operation. This allows the user to control if and when the bike is in closed-loop simply using the AFR table.

For tuning of the VE tables, the recommended method has not changed. The AFR table should be set to 13.2 in all cells; this will put the bike into open-loop operation. The VE tables are then tuned to achieve the 13.2 in all conditions. Upon completion, the AFR table should be returned to its previous settings. This will return the bike to closed-loop operation.
The new table that has been added this year is the Closed-Loop Bias table. This table is used to shift the AFR richer or leaner during closed-loop operation. This table is a function of engine speed and map load. The cell values are the switching voltage that the ECM controls to. A lower voltage will control leaner, and a higher number controls richer. This table is used by the ECM in addition to the AFR table to determine what AFR to control to.

Example: Using calibration 141NX001. Looking at 1750 rpm and 40 kPa, the AFR table shows 14.6 and the Closed-Loop Bias table shows 447mV. With these values, the ECM will be in closed-loop operation and will control to approximately 14.4. In order to change the fuel delivered to the engine in this condition, the Closed-Loop Bias table would be used. 500 mV will make the mixture slightly richer, and 400 mV will make the mixture slightly leaner.

Changes to the Closed-Loop Bias table are done for the same reasons the AFR table would be changed: power, fuel economy, knock, etc.
 
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