Dual Edge MAP Enhancer Instructions

The Basics

First lets clarify some basics. MAP = Manifold Absolute Pressure. A MAP sensor measures the pressure in your intake manifold. MAF = Mass Air Flow. A MAF sensor measures the amount of air coming in to your engine. These devices are designed so similarly that a device that works for a MAP also works for a MAF. Further, their information to the ECU is used similarly, and therefore adjustments to these 2 types of sensor will have a similar result. In the early days of the HHO industry, the MAP sensor was often treated, and so you will see devices sold on Ebay called "MAP Enhancers". These could just as well be called MAP/MAF Enhancers because they will work on both. For ease of speaking, we usually just say "MAP Enhancer" or MAPe for short. But in all of these cases, we mean "MAP/MAF Enhancer"

Many vehicles have a MAF or a MAP sensor, but not both. In these cases you will treat the sensor you have. Some vehicles have both a MAP and a MAF sensor. In these cases you are best off treating only one of the 2 sensors. Treating both can cause too much variation and the computer can have trouble maintaining a correct air/fuel ratio. I usually start by treating the MAF sensor, however, some vehicles that have both types of sensor respond better treating the MAP. So if your vehicle has both sensor types, and your treatment of the MAF hasn't gotten you results, try the treating the MAP instead.

Two Types of Sensor

There are 2 types of each of these sensors. The most common is a "voltage type" MAP or MAF. The voltage type communicates to the ECU by giving it a voltage, and this voltage tells the ECU what the MAP's current pressure reading is, or the MAF's current volume of air flow. The ECU gives a control voltage to the sensor of 5 volts. The sensor then gives back a fraction of that 5 volts that signifies it's current reading. The vast majority of all MAF and MAP sensors are of this type. Our Dual Edge MAP/MAF enahancer handles these types of sensors.

The other type of sensor is a frequency type. In this case the sensor communicates with the computer by means of a frequency. Both MAPs and MAFs sometimes use this method. The sensor is measuring the same thing as the voltage type, but instead of providing the ECU with a changing voltage, it provides a changing frequency. Ford used to use this type of MAP extensively in the 80s, but has since changed back to using voltage type. But you need to know about this type of sensor. Our Dual Edge MAP Enhancer will not work on this type of device. Neither will the MAP enhancers you can get on Ebay, even if they say otherwise. If you have a frequency type MAP or MAF you will need our Frequency MAP/MAF Enhancer. This is a device that can read a frequency and then provide an adjustable lower output frequency to the computer.

Finding the Signal Wire

The first step to installing your MAPe is to find the signal wire. Of course the easiest way to find the signal wire is to get a wiring diagram for your vehicle. This can tell you the exact wire, and it's color code, and save you some time. For resources on getting wiring diagrams for your vehicle, see our article: Wiring Diagrams. But if you don't have a wiring diagram, you can still find your signal wire by measuring it.

A MAP or a MAF will have 3 wires. One will by 5 volts, which powers the device and is supplied by the ECU. One will be ground, or 0 volts. So if you measure the 3 wires, just eliminate the 5 volt wire and the 0 volt wire, and the remaining wire is the signal wire.

This is slightly complicated by the fact that many MAF sensors today also include an Intake Air Temperature sensor in the same housing. In this case you'll have 5 wires going to the sensor. But it's OK, it's easy to find the correct wires you need. The temp sensor will have a ground wire and a signal wire. The signal wire will be up near 5 volts when the sensor is cold, but as it heats up that voltage gets lower. But a temp sensor's voltage will not change when you goose the engine, and that's how you can tell the difference. Also, if you unplug the sensor, and measure the signal wire on the computer side, it will read 5 volts.

Tip: You can steal a straight pin from your wife's sewing box and push it through the insulation of the wire you want to test. Make sure you get into the conductor (wire) inside. This will be much easier than scraping away the insulation to test the wire.

Even if you find your signal wire using a diagram, you should still test it before proceeding. You must make sure that you see a voltage change when you rev the engine, and that the voltage drops back down when the engine slows back down again. If you see this phenomena, you can proceed to install the circuit. If you don't see this phenomena, then you have the wrong wire, or an incompatible sensor type. The biggest single cause of failure for any sensor modification project is to mis-identify the signal wire. So it's best to be absolutely sure.

Connecting the MAP Enhancer

The MAP Enahncer will need a hole drilled for the wire. We have not drilled this hole because we wanted to give the user maximum flexibility in how he mounted the MAPe. For a completely clean install, drill a hole in the back of the device so you can run your wire directly through a hole in your dashboard. This method will hide the wire completely. If you don't wish to drill a hole in your dash, then you should drill the hole in the side or the bottom of the box. The best size hole for the cable we provide is 3/16".

See the diagram above. You cut the signal wire. You then extend these 2 wires up to the MAPe. The diagram below shows which terminal to use for each of the wires. We recommend soldering the joints to your sensor's wires. You also must insulate them electrically. You can use heat shrink or electrical tape for this. We also recommend you use the same color scheme we have, so that you can later refer to these instructions and know what each wire is connected to.

Earlier versions of this product did not have the 12/24 volts out terminal. This terminal is for use in controlling other devices, such as your PWM, and/or EFIE or other electronics. It is controlled by the MAPe On-Off switch. You must not use this wire on the high current side of a PWM as it will burn up the circuit board. But you can use it on the control circuit. Nearly all PWMs have a separate control circuit that activates the PWM. This is a low current wire that if interrupted will cause the PWM to shut down. All FuelSaver-MPG PWMs have this wire which connects to the green terminal block. In this way you have a way to shut down all of your devices at once by turning off the MAP Enhancer.

Now, connect the ground and 12 volts power. The power connection should be switched power. Don't go directly to the battery.

Notes About the Power Connection

The power connection needs a little more explanation. Most MAPe's don't use a power wire at all. We feel that this is a problem. We use a power wire on this device was so that you can power it from the same place that you are powering your HHO system, or other fuel enhancement system. If power is off to the HHO system, then it is also off to the MAPe. Our MAPe is designed the same as all of our electronics products: when power is cut off to it, it will revert back to the stock signal. There is a relay inside the MAPe that connects the signal wire directly to the computer when the power is off. It only makes changes to the signal if it has power, and if the switch is turned on. This way you can never have your MAP signal altered when it shouldn't be, and vice versa. Furthermore, any devices connected to the <12/24 Volts Out> terminal will also be shut down.

Using Your MAP Sensor Enhancer

You will probably want to start your engine in factory position (Off-On switch set to Off). You may not want the air/fuel ration leaned out at start up. Starting the engine in full adjustment can sometimes turn on a check engine light. You'll have to test with your specific engine to find out how it reacts. Most don't have a problem, but alert to this.

Adjustment Procedure: First adjust both knobs all the way counter-clockwise – this will be to the full rich position. It is the same as no change at all to the sensor signals. Set the City-Hwy switch to City to start with. After the engine has been running for a few minutes, slowly turn the “City” knob clockwise. Continue turning clockwise until you feel the engine start to lug down a bit. Then back it off until the engine is running freely again. Next, switch to the Hwy setting. Adjust this in the same manner, however do the setting while you are driving at highway speed. When you are driving in Hwy mode, but need more power, such as when towing or driving up steep grades, you can switch to City mode. Usually the City setting is not as lean. Play with these settings as needed so that the engine never has any power loss, but fuel mileage gains are maximized.