Information on the Mazda LF-VE 2.0L Engine. This is refered to as an MZR engine and is found in the NC MX5 Miata.
They are also commonly referred to as a Ford Duratec engine, which differs from the early Zetec variants from Ford that were also called Duratec.
Volvo also use this engine under the B4204S3 and B2404S4 names.
The main focus will be on the MX5 variant.
Haltech ECU Options
Only Elite 1500 and 2500 models support these engines.
Cylinders
| 4
|
Displacement
| 1999 cc / 122 ci
|
Firing Order
| 1,3,4,2
|
CAN
This vehicle uses CAN bus for various devices throughout the vehicle. This can include the dashboard, ABS, and Body Control.
Model Variants
There are a number of variants of the Mazda LF engine. The MX5 version is longitudinally mounted however there are transverse mounted versions of this engine in other vehicles.
LF-DE
10.0:1 comp, no-VCT, no balance shafts (found in 2.5L versions), stainless headers and cat
LF-VE
MX5 NC variant, 10.8:1 comp, Mazda S-VT (Sequential Valve Timing) on inlet cam, increased inlet valve lift, variable intake length
2009-on forged crank, new pistons, valve springs, rod bearings, 7500rpm limit
LF-VD
Direct Injection (NOT SUPPORTED), later models get exhaust VCT and 12.1:1 comp
Known Issue
Intake
The plastic intake manifold on early versions has a major fault due to poor-quality materials. The manifold has swirlplates mounted on a square shaft at the aperture where it mounts to the cylinder head. Early four-cylinder Duratec engines can be ruined when the swirlplates break off and enter a cylinder. Most cases are of single swirlplates but also the shaft can wear and break. Early signs of this fault are evidenced by a ticking noise emanating from the front of the engine. This can occur as early as 25K miles, with failure typically occurring after about 90,000 miles.
OIl Consumption
Valve stem seals after 100k miles, rod bearing wear.
Thermostat
Commonly fail around 60k miles. Engine overheats or is slow to warm up.
Crank/Cam Sensor
This engines uses a Crank Position Sensor and a Cam Position Sensor.
The crank trigger wheel is part of the front crank pulley and has a total of 36x teeth. It has 1x group of 2x missing teeth, and opposite are 2x groups of 2x missing teeth separated by 1x tooth.
The cam trigger has 4x equally spaced teeth with 2x adjacent teeth having an extra tooth each.
Crank Trigger Pattern
Cam Trigger Pattern
Trigger Configuration
Crank Sensor
A Hall Effect crank position sensor is used.
Hall Effect Wiring
Pin
| Description
| Haltech Connection (Trigger 4-core)
|
A (G/R)
| Signal Ground
| Blue
|
B (G/Y)
| Signal
| Trigger+ Yellow
|
C (L/O)
| Power (5V+)
| 5V+ Orange
|
Cam Sensor
A Hall Effect cam sensor is used.
Hall Effect Wiring
Pin
| Description
| Haltech Connection (Home 4-core)
|
A (L/B)
| Signal Ground
| Blue
|
B (R/B)
| Trigger +
| Yellow
|
C (LG/B)
| Power 5V+
| 5V+ Orange
|
Ignition Coils
The ignition coils feature an internal igniter. These can be wired directly to the ECU.
They are ECU dwell controlled so they use Constant Charge with a Falling edge.
Alternately you can use the internal MAP sensor that comes with your Elite ECU. For higher boost levels an external MAP sensor should be used instead, connected to a spare AVI.
Variable Cams
The LF-VE engine comes with continuously variable intake cam timing control. Mazda refers to this as S-VT (Sequential Valve Timing).
This is configured in the Haltech ECU as Cam Control. The Intake Cam 1 Input should be set to Home. Use any spare output other than Ignition Outputs to control the cam solenoid.
Variable Intake Length
The LF-VE comes with variable intake length control. This uses any spare output to control the switched solenoid. This is switched to be ON below 3000 RPM.
Variable Tumble Valve
The LF engine comes with a set of throttle plates located near to the cylinder head in each runner. These are designed to improve airflow tumble under cold or idle conditions. This can be controiled by the Elite ECU via a Generic Output.
Idle Control
This engine uses the Drive By Wire Throttle to control idle speed.
Coolant Temperature
The Coolant Temperature Sensor is lcoated on the thermostat housing at the back of the engine.
Wiring is not polarity sensitive
Pin
| Haltech Connection
|
1
| Any Spare AVI*
|
2
| Signal Ground
|
An AVI with a selectable Pullup should be used. If not and external 1k pullup to 5V should be connected.
Calibration: Use "Temperature - xxxxxxx.cal"
Created for Haltech ECUs using a 1k pullup to 5V
Air Temp
The Air Temperature Sensor is part of the MAF Sensor. See the MAF Section for wiring information.
If the MAF has been deleted an Air Temperature Sensor should be installed in the intake.
Knock Sensor
A knock sensor is fitted to these engines and can be used with the Elite ECU.
Pin
| Haltech Connection
|
A
| Knock Signal
|
B
| Signal Ground
|
MAF Sensor
The MAF Sensor is part of the airbox lid. Although most users of Haltech ECUs will be deleting the MAF, it is possible to use a MAF if you prefer.
Pin
| Description
| Haltech Connection
|
A
| 12V+ Switched
| 12V+ Grey/Red
|
B
| MAF Signal Ground
| Signal Ground
|
C
| MAF Signal
| Spare AVI
|
D
| Air Temperature Signal
| Spare AVI with pullup enabled
|
E
| Air Temp Signal Ground
| Signal Ground
|
O2 Sensors
This engine comes fitted with a pair of 4-wire heated narrow band sensors. For accurate tuning the front O2 sensor should be swapped for a Haltech WB1 Wideband Kit.
Adding a Haltech Single-Channel Wideband WB1 Kit (highly recommended)
For correct operation a Haltech WB1 kit is highly recommended for this application, with the provided 4.9 sensors replacing the pre-cat sensors. Sensors use a 22mm socket or spanner to remove and replace.
Vehicle Speed Sensor
Only MX 5 NC models with Manual Transmission and no ABS/DSC system have a vehicle speed sensor. All other models receive this data over CAN from the ABS Controller.
This engine uses a Hall Effect Vehicle Speed sensor.
Injector Data
Flow
The injector flow rate is measured with the injectors held wide open at 100% duty. For fuel systems with a fixed regulator pressure (often returnless systems) that is not referenced to manifold pressure the flow needs to be mapped over Manifold Pressure for accurate tuning.
LF-VE Injector Flow: 240cc/min
Dead Time
When an injector is commanded to open for a certain amount of time, the dead time is the amount of time the injector is not actually open during this period. It covers the time to energise the solenoid and begin to open and the time to close as well. There are also transient periods during which the injector is opening and closing where fuel flow is not at full capacity so this lost peak flow period is also taken into account.
Location
The OEM ECU is located in the engine bay near the airbox.
ECU Pinout