The 034 EFI STAGE II ECU is a progression of the original low cost, feature packed 034EFI ECU. The original was a fuel only engine controller that allowed a straightforward approach to replacing factory CIS, carbeuration and other EFI fuel control. The STAGE II ECU continues with an even faster microprocessor used in some of the newest factory OEM applications. Unlike other controllers on the market with processors developed in the 80's, the STAGE II ECU uses the fastest, most up-to-date microprocessor available. Ignition programmability is now also a part of the 034 EFI product, including Direct Fire Distributorless! For the ultimate in tuning accuracy and performance, now fuel and ignition can be programmed precisely for every application. STAGE Iic is now available, and all a, b and c levels of the STAGE II ECU use the same hardware, so upgrading to the next level is a simple software flash away, upgrading the controller will never be necessary.The ECU uses what is often called the speed density method for fuel calculation. The basic operation is simple. The ECU receives trigger information from the hall sender or a timing wheel, and fires ignition and injects fuel with a pulse width that is proportional to the engines current load. The 034 STAGE II ECU uses many other variable parameters in order to precisely control any engine. These parameters are variable because different engine systems need different values to control an running performance. This is why few people successfully adapt OEM engine controllers for use on different engines that were not designed for that system.
See our Featured Users section for setup examples here.
STAGE IIa - $ See catalog for pricing
(Fuel Only, 1 GPO, includes raw wiring and ECU connectors, flying lead harness available for $30)
STAGE IIb - $ See catalog for pricing
(Fuel, Distributor Ignition, Idle Control, 1 GPO and more, includes raw wiring and ECU connectors, flying lead harness available for $40)
STAGE IIc - $ See catalog for pricing
(Features Direct Fire Ignition, 4 GPO's and more, includes raw wiring and ECU connectors, flying lead harness available for $50)
Other available 034 EFI Solutions available HERE

The 034EFI STAGE II ECU is developed to be:
- Powerful - Flexible - Accurate - Value packed - Easy to tune - AND Affordable Please read more about the 034EFI Stage II Specifications below...


  • 8 ignition and 8 injector drivers will support up to 8 cyl direct fire/sequential, or up to 16cyl semi-sequential and semi-batch fired.
  • Operating Temperature -40 to +85° C
  • Battery Voltage Range +6.0 to +20 VDC continuous
  • Current Consumption 0.05 - 20 Amperes [@ 100% duty cycle]
  • Injector impedance: High or Low impedance, 12+ ohms recommended for multiple injector per channel. Coil Support, built in driver (TTL) or standard 2-wire grounded coil.
  • Maximum RPM 25,000+, tested at over 35krpm.
  • Trigger Modes:
    -Stage IIa and IIb: Hall Effect or VR Sensor (multi- window (or equal # of cylinders, cam driven) factory distributor or cam gear equipped)
    -Stage IIc: Hall or VR, 60-2, 60-1, 36-1, 24-1, 20-1, 12-1, Chevy LS1 and others. 0-5 volt signal or low current 12v signal.
  • Injection Timing Resolution .001MS (1 microsecond) to 65.535 millisecond [16 bits]
  • Ignition Timing Resolution 1/4 degree.
  • Communications High Speed RS-232 with STD 9 pin D interface
  • Packaging Stamped aluminum casing with dampening rubber feet, black powerdercoating, 10.5"l, 6.5"w, 1.5"h (including connectors and feet)
  • Programming/Tuning VIA WIN95/WIN98, XP, etc and RS232 port
  • Engine Support: Fully valve timed sequential fuel with distributor fire ignition for Stage IIc

Sensors Supported:

  • Hall Sensor 5volt or VR sensor
  • Throttle Position [TPS] 3-wire universal
  • Coolant Temp [GM Type, 2700ohm @ 25° C], most Bosch water temp. including Motronic.
  • Induction Air Temp [GM Type, 2700ohm @ 25° C], most Bosch including Motronic (except some ME5.x)
  • Auxiliary Input [0-5vdc]
  • Manifold Pressure 1, 2.55 or 5 Bar Absolute [Provided in enclosure].
  • EGO Sensor [1,3 or 4 wire only]-closed loop operation, programmable by user. Wide band 0-1v converted signal also supported.

Screen Shots:










See ECU pinout documents (.doc files) ConnectorStage IIaStage IIbStage Iic
See ECU Manual
See 034EFI Stage IIa Ignition Supplement (PDF)
See Tuning manual for 034EFI Stage II


FUEL CONTROL Stage IIa, b, and c
Sequential Valve-timed operation:
Each phase drives a single injector typically in the intake port, and near the intake valve. This configuration fires a single injector pulse to each injector every two-engine revolutions. The phasing of the injection can be timed to TDC or any position of valve actuation desired.
Closed Loop Operation:
Using a standard 3 or 4-wire narrowband, or 0-1v wideband output from a 3rd party wideband controller (recommended) O2 sensor, the ECU will run in closed loop operation according to a programmable MAP x RPM matrix where different air/fuel ratio values can be entered.
Acceleration Enrichment:
Acceleration enrichment values are programmable according to TPS speed and minimum and maximum pulsewidth values ensures smooth running, shifting, throttle response and acceleration.
Temperature Compensation:
Air and Water temp. inputs are programmable to allow the fuel curve to be adjusted by air and water temp increases/decreases.(Temp Compensation Screenshot)
Cold and Warm Start Supplementary Pulsing:
Extra pulses at a user dictated pulsewidth and temp range can be programmed to replace the cold-start-injector function to allow smooth starting when engine is either hot or cold.
Data Logging:
A Time vs. Signal map will accurately track and save-to-file sensor outputs for further analysis. Sampling rates from 2 seconds to 100ms. Logging can be exported to Excel and manipulated, including graphing, statistical analysis using Solver and other tools. A great tool for monitoring water temps, intake air temps, air/fuel ratio, RPM, Injector PW, MAP, Aux. Input, etc. (Plotter Screenshot)
TPS mapping:
A RPM vs Throttle Opening matrix allows detailed mapping of part throttle fuel manipulation where WOT can be more accurately MAP based due to a more stable manifold pressure, but more inconsistent manifold pressure at part throttle openings can be dictated by throttle opening vs. MAP.
Fuel Map Downloading:
At any time, all the parameters in the ECU can be downloaded to a file on the computer for future reference, or for differing conditions. Maps can be downloaded or uploaded "On The Fly" to analyze differences between different fuel maps, or to compensate for different injector size, boost pressure, camshaft specification, altitude, weather condition, track/street driving, fuel type, etc.
Auxiliary Sensor Input:
This input is provided to allow the user to connect a signal-conditioned sensor to modify the engines performance. Possible Uses would be to allow a cockpit fuel trim control (using a 0-5v regulator), or allow some other sensor such as an exhaust temperature sensor or MAF to add or subtract basic fuel according to the tunable Auxiliary mapping table. A 0-5v range is required.
4 Auxiliary Driver Output "GPO" (General Purpose Output):
4 separate PWM (pulse-width-modulated) outputs are available and programmable using RPM, MAP, Water temp, throttle position and aux. input. These drivers can be used for electronic boost control, water injection, nitrous-oxside, launch control, variable valve timing, cooling fan, fuel pump relay trigger and many other uses. (GPO Screenshot)
Closed Loop Boost control:
Uses one of the GPO outputs to control a solenoid valve to manipulate pressure to the wastegate actuator. 9x9 fully programmable boost map allows tailoring of the boost 'curve' for any application.
32 Bit Graphical Programming Package:
To ensure that programming and tuning of the 034 EFI Stage II is as simple and pain free as possible, it has been developed as a software package that runs under 32-bit Windows programming that is both intuitive and packed full of features that power users want and need for flexibility. Each unit comes with programming software, which allows full monitoring of all sensory inputs, and allows full tuning capabilities.
3 Dimensional 16x16 matrix Fuel Mapping:
16RPM (X axis) points by 16Manifold pressure (Y axis) forming an 16 x 16 Matrix (256 points) allows very detailed programming of the fuel curve. The engine specific behavior can be adjusted as required to accommodate poor volumetric efficiency due to cam overlap, engine resonance, or other engine specific issues that can be attributed to a specific manifold pressure/RPM range. Many engines require little or no adjustment of the mapping parameters, while modified, high compression, or heavily cammed engines may need some work in the mapping, particularly at lower RPMs where manifold vacuum is poor or unstable.
Sensor Power Voltage Protection:
Since it is necessary to provide an external +5v supply to some of the external sensors, we have provided a self resetting circuit breaker that will open in the event that a +5v to ground short occurs on any of the sensor channels. This circuit also functions to save the ECU from damage, when a +12v line is accidentally connected to the +5v supply.
Configurable RPM range:
To Calibrate tachometer settings, Stage II ECUs allow a full scale RPM range to be specified so that the user will be able to get the most possible resolution from the RPM axis in the 3D mapping. It wouldn't’t make a great deal of sense building a 5000 RPM RV engine, but having 10000 RPM mapping range if the engine never sees the second half of the RPM portion of the map. (Configuration Screenshot)
Configurable Rev-limiter:
Rev-limiter can be set to any RPM within the functional range; it is a soft-touch limiter that cuts fuel to every other injector, unlike the factory all or nothing fuel cut out. Typically, the factory rev-limiters are set in the 6800RPM range, the stock rev-limiter should be disabled to set the ECU rev-limit higher than that point.
Barometric Pressure Compensation:
This configuration that allows tunable compensation from a sensor that reads the local barometric pressure. This feature is useful for vehicles that are expected to perform well in significantly varying altitudes.
Sequential Fuel Injection Via Camshaft TDC Hall Sender:
The 034ECU pulses each injector based on 5 pulses for each time the cam turns one revolution. It will read this signal from any factory hall sender that uses a 5-window distributor such as in all the normally aspirated 4kq and 80/90q cars. The turbo cars are equipped with a one window distributor, and thus will need a hall sender mounted near the cam gear with 5 steel pins will be required, or the use of the 5-window distributor. The 1-window hall wheel can also be modified to the proper # of cylinders. Iic system degree based and thus Sequential regardless of cam TDC reference.
Fuel Pump Relay Output:
Allows battery savings when engine is not turning. Can also be used as a rollover fuel shutoff control. Will prime fuel pump temporarily just like the factory systems, shuts off fuel pump as soon as RPM stop. This output is a ground trigger, always power fuel pump with a load reduction relay.
Tachometer Output:
The ECU will drive any standard tach through a convenient output.
Battery Polarity Reversal Protection:
Should the battery be installed, or jumped incorrectly, no permanent damage will occur to the ECU.
Power Spike Protection:
A high current surge-arresting device has been fitted to the ECU that protects the ECU from high voltage transients such as a starter motor load dump.
Back EMF Protection on ALL driver outputs:
Circuitry includes protection for driving inductive loads on every driver output. The back EMF voltage is clamped to approximately +40 VDC.
External Input Protection:
Each of the sensor connections and external inputs have protection circuitry to prevent damage to the ECU in the event of an unplanned connection to a voltage source outside the normal operation of that channel. This is especially useful in preventing damage to the ECU from improper connections, or accidental shorts of sensory inputs to the +12v supply.
Battery Voltage Compensation:
A Pulsewidth affect value for voltage compensation can be entered.


Distributor Ignition Control:
Will fire with most stock and aftermarket distributors using hall senders with one window for each cylinder.
High Current Coil Output:
Will drive most standard and high performance coils past 45KV and up past 25,000 RPM
Ignition Timing Retard:
Based on MAP, RPM, and MAT (Manifold Air Temp), up to 20 degrees of dynamic retard can be programmed from a static initial advance setting giving fully accurate timing control under varying conditions in varying applications. (Ignition Mapping Screenshot)
Configurable Coil Settings:
Allowed to accommodate a variety of coils and to tune to the maximum capability of any coil including Target Dwell Time, Min. Dwell Time.

Stage IIc Features

CAN Based Expansion and datalogging support:
Supports CAN protocols for both expanding with other 034EFI modules, like a wideband and EGT controller, as well as constantly outputting a datalogging stream in the Bosch MS3.1 standard. This means that virtually every race dash on the market is able to log information from the 034EFI ECU high speed, and real-time. Keeping all of your test and race data in one place when you're out on the track.
Full Distributorless Ignition Control:
Using a toothed wheel for RPM and TDC Reference, will run any engine from 1-16 cylinders, Coil-On-Plug 1-8 cylinders, and waste spark up to 16 cylinders. Timing accuracy to 1/4 degree, the ultimate in ignition timing accuracy and power!
Degree Based Ignition Control:
Where distributor systems and even some DIS systems often run on inaccurate "event based systems" where 1 trigger signals the ECU to an upcoming ignition event, 034EFI Stage Iic calculates timing on a fully "Degree Based System" meaning the ECU always has complete information on crankshaft position, down to a very fine degree. This is the only accurate way to calculate ignition timing for high performance, "distributorless" systems.
Cylinder-By-Cylinder timing Control:
Because the system is degree based, different ignition phases can be "advanced or retarded" by the degrees the event occurs at, this allows the ultimate ignition tuning strategy not only for the entire engine, but for each cylinder! (Ignition Mapping Screenshot)
Ignition Timing Retard:
Based on MAP, RPM, and MAT (Manifold Air Temp), up to 20 degrees of dynamic retard can be programmed from a static initial advance setting giving fully accurate timing control under varying conditions in varying applications.
Dual Stage Rev Limiter:
A dual stage rev-limiter is implemented in Iic to provide a smoother, more accurate rev-limiter of engine speed. In addition to the standard fuel cut rpm limiter, a programmable timing retard is also used to pull power before the fuel cut is realized. Thus, the driver will begin to anticipate the fuel cut by feeling power drop off as ignition timing is pulled back. Timing values from 0 to -50 can be used to accomplish this. For more information, see the Tuning Manual.
Launch Control and Anti-lag:
Using the Aux. input, a second stage timing retard based revlimiter can be implemented to facilitate Launch Control or Anti-lag capabilities.
Configurable Coil Settings:
Allowed to accommodate a variety of coils and to tune to the maximum capability of any coil including Target Dwell Time, Min. Dwell Time, as well as adjusting dwell times based on manifold pressures
High Current Coil Output:
Will drive most standard and high performance coils past 45KV and up past 30,000 RPM (tested)


IAC Configuration Settings:
Using a universal GM-style IAC the 034 EFI Stage II system will drive to a high level of accuracy idle speed, fully programmable.
Idle Temp Compensation Map: 
Different idle speed settings can be configured based on engine water temperature.
Ordering Information
ECU's are available immediately. We can usually ship the unit within 2-3 days of an order.
**NOTE: This is NOT a bolt on system, and is not smog legal. Anyone with little fabrication experience, or those who want a turnkey project car should stick with the limited, stock fuel system. Though this system is easy to program, and will result in magnificent performance, it will require a period of tuning until the fuel and timing curve is acceptable under varying conditions and circumstances. If you like to fabricate, like to tweek, are patient, and find enjoyment in a project well done- please contact us with any questions and uscan move forward.