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2,100 Posts
You have a Delphi.

While the PCIIIr will work with either MM or Delphi systems it appears the Delphi bikes are significantly less happy in the long term with them then the MM bikes.

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2,100 Posts
Possibly the SE EFI tuner, but it is new and requires significant knowledge as well as time investment.

With a few exceptions you will not find these, in particular the willingness to invest time, at a dealer service department.

I'm willing to wager, despite it's significant capabilities, that unless you are able to program it yourself it will be no better then a reflash, and it isn't cheap.

If on the other hand you have tuning knowledge and significant computer literacy it will likely turn out to be the best thing that ever happened for bikes that run the Delphi.

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251 Posts
Get the SE EFI Tuner kit. It obsoletes anything else for tuning 2001/2002 HD EFI ECM. I use it on my 2002 Ultra and it is the real deal. To know what calibration you are currently running if installed by a dealer look at page 452 of "The Book". While you can pay to have these flashed you cannot purchase them to modify. The EFI Tuner has equivalent calibrations which you can modify and load - just a different number and not as EPA friendly. This ways after you screw it up the dealer knows you have been in the ECM and gets to charge you $150 to reflash you back to where you started.
Should be able to buy the SE EFI tuner for $350 on 20% off.
Its all about ping and power!!

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25 Posts
Hippo, new guy here...what is the difference between the MM feul injection and the Delphi ? Also, what does the MM stand for ? This may sound like a dumb question, but Daddy always said I would never know unless I ask.

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2,812 Posts
This'll explain the 'Delphi' ESPFI

tbone said:
...what is the difference between the MM feul injection and the Delphi ?

Have fun! :D

Introduction-Harley-Davidson EFI Systems



This completely new engine management system was released starting with select 2001 model year Softail motorcycles. This system is a speed/density, open loop, sequential port fuel injection design that also controls spark timing and spark intensity.

Speed/Density System - When the ECM monitors manifold air pressure, air temperature, throttle position and engine rpm to manage fuel delivery.
Open Loop Control - When the ECM monitors sensors positioned on the intake side of the engine and does not monitor the end result of internal combustion at the exhaust.
Sequential Port Fuel Injection - When the injector nozzle is positioned in the manifold near the intake valve and is precisely timed to deliver fuel to each cylinder.

This ESPFI system is the exclusive design used on select 2001 and later Softail models and select 2002 and later Touring models.


The following is a list of the major components of Harley-Davidson's current ESPFI system. It is important to have an understanding of what these components do before learning how the ESPFI system functions. Refer to the appropriate Harley-Davidson Service Manual for the vehicle you are working on for additional information on component design and function and for the physical location and testing procedures
for each individual component.

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.

CKP - Crank Position Sensor - this sensor provides input signals to the ECM that indicate engine rpm, (how fast the engine is running in evolutions 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.

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.

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.

ET - Engine Temperature - this sensor provides input signals to the ECM as it reacts to the engine temperature of the front cylinder head. The ECM uses the signals from this sensor to determine if the engine is at operating temperature, or warmingup.

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.

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.

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.

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.

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.
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.

Electric Fuel Pump - a 12-volt high-pressure fuel pump, (located in the fueltank) supplies fuel under pressure to the fuel injectors.

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.

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.

As mentioned, the ECM is the brain of the ESPFI system. And, like our own
brain, it has memories and it makes decisions. The ECM memories are located in Look-up tables.
The ECM uses several different Look-up tables to make decisions on fuel and spark management. The Look-up tables that are in constant use by the ECM are the VE, (Volumetric Efficiency), AFR, (Air Fuel Ratio) and Spark Advance tables.

One type of Look-up table the ECM always uses is for VE, which 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%. And, if the engine flows
about 157cfm at 5600 rpm it would have a VE of about 110%. That's right, 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. The VE Look-up tables in the Screamin' Eagle calibrations are calculated from data they gather while testing live engines on engine and chassis
dynamometers, and with data acquisition equipment in conjunction with track testing.


The front and rear cylinder VE Look-up tables, which are programmed into the ECM, tell the ECM how much air, (volume) is flowing into the engine at different engine rpm and throttle positions.

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 determinedby monitoring manifold absolute pressure and engine rpm) to produce the performance that's desired.

The front and rear Spark Advance tables, which are programmed into the ECM, tell the ECM the spark advance desired for specific engine loads to produce the performance that's desired.

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

- 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 when it refers to the VE Look-up tables. From this information the ECM knows the volume of air that should be entering each cylinder at this moment, under these 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. Air density tells the ECM how much oxygen is in the air entering the engine.

-Now the ECM knows exactly how much oxygen is entering each cylinder and it refers to the AFR Look-up table for the AFR that's desired. It then sends the appropriate output signals to the fuel injectors to achieve the AFR it has been programmed to deliver for the current engine rpm and engine load.

-The ECM also refers to the Spark Advance Look-up tables for the desired spark advance for each cylinder according to 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.

-When the engine is experiencing a temporary condition such as when the bike is being started on a cold morning, it uses additional Look-up tables that are also programmed into the ECM. 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 look-up table and directs the fuel
injectors to remain open longer, (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 a Warm-up Enrichment look-up table that it uses to add the additional fuel needed while the engine is still cold. The table is designed to diminish its affect, (referred to as "decay value") to zero as the engine comes up to operating temperature.


The ESPFI systems on 2002 Touring and Softail series bikes also incorporate a sophisticated heat management system that operates in three-phases to keep things cool in extreme conditions.

Phase I: 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.

Phase II: 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.

Phase III: 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.

The 3-Phases just described function seamlessly, and the rider may not notice the transition from one phase to the next.

· Registered
138 Posts
Harleyhog-->Where did you pull this info. from?

· Registered
379 Posts
What was the V-speeds again, particularly VR. .... nah, very nicley written harleyhog. I'm sure people will be refered to that which you have written for along time to come.

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2,812 Posts
2DEUCE said:
, very nicley written harleyhog.
Why,Thank you very much (psst, its a copy)
Just don't go tellin the MOCO copyright people! :D
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