Frequency MAP/MAF Installation Instructions

These are the instructions are for our new Frequency MAP/MAF Enhancer, or "MAPe" (MAP enhancer) for short. Before proceeding you should have a look at our article, A Simple MAP/MAF Enhancer. It has a good deal of information about MAP and MAF sensors, the different types that exist and how to find the signal wire you'll need for the installation. Our Frequency type MAPe will also work on voltage type devices. But you still need to determine which type you have. The link above will help you with that.

Once you have your signal wire, its very important to know if you have a frequency or voltage based signal wire. By measuring for DC volts, you can't really eliminate a frequency device. A DC meter will still show a DC voltage on an A/C signal. It kind of averages the voltages out. Usually it will even show you changes to the "DC" voltage when you goose the engine. So the bottom line is that the best way to find out if its a frequency type device is with a frequency function on your meter. If you have not yet purchased our frequency MAPe, then it would be a good idea to buy or borrow a meter with the frequency function, and test your signal wire. You may be able to use a cheaper, voltage based MAPe.

If you don't have a frequency function on your meter, but have already purchased our MAPe, you can also set it up for frequency usage, then hook it up. The green LED will only light up if its a frequency type device. It will light up almost instantly. If its voltage type, the green LED won't light up. Don't worry, it won't hurt the device to test it in this way. If the green LED doesn't light up, then you can hook it up as a voltage type device and it will work.Note: We've had reports from guys with Dodge diesel engines, that the MAP doesn't start putting out a frequency signal until after the engine has warmed up. So, realize you may not get a frequency signal right away. However, once a frequency signal is available, the green LED will light up instantly.

Once you have found the signal wire, then you will cut it, and run the 2 ends into the MAPe. The diagram below will show which terminal to use for the sensor wire, and which to use for the computer wire. Note that there are different terminals for frequency type or analog type signal wires. You must use the correct terminals for the type of signal you are trying to handle. Note that the MAPe can only be used for one device. It can't be used for both a frequency MAP and an analog MAF at the same time. Only one set of terminals will work, and that is based on the positions of the switches (see below).

Terminal Block Key

Frequency MAP Switch Positions

Setting the Switches

The image above shows the switch that is used to configure the Frequency MAP/MAF Enhancer. The list below shows the functions:

  1. Used to switch between different types of voltage signals - see below for details.
  2. On for voltage type signals, off for frequency type signals.
  3. On to raise the frequency, off to lower the frequency. On is for raising horsepower only.
  4. Not used.

For frequency applications, all 4 switches should be in the "off" position. This will cause the frequency to be lowered by the amount of the pot position. However, performance guys that want more horsepower, at the expense of fuel mileage savings, can put switch 3 to "On" to get more fuel.

For analog applications, switch position 2 must be on. That is vital. In nearly all applications switch position 1 will be off. However we have seen a rare instance of a voltage MAF sensor with reversed logic that needs this switch set to "On".

Switch position 1: Most analog voltage applications require that the output voltage be lowered in order to lean the mix. In that case switch position 1 should be "Off". Rarely, some analog voltage MAP/MAF devices work in the opposite way. In these cases you need to add voltage, rather then subtract voltage. It is very rare. But to work with these devices, put switch position 1 into the "On" position. This will cause the voltages to be higher when the pot positions are increased, rather than lower. I've never personally seen one of these types of device. But I have seen the documentation on them.

Setting the MAPe

Frequency Mode: When setting the MAPe in frequency mode, start with Pot B at zero (all the way counter-clockwise). Make your adjustments using Pot A only. The more you go clockwise, the more frequency adjustment there will be. If you turn Pot A all the way to maximum and still need more adjustment, then use Pot B. Leave Pot A at maximum and start adjusting Pot B.

Analog Voltage Mode: Set pot B at its midpoint. Get a rough adjustment using Pot A. You can do that by ear. After you have gotten roughly the correct adjustment, use Pot B for fine tuning your adjustment. Pot B is 10 times more sensitive than Pot A, and is used for fine tuning only. Anytime you are going to change the position of Pot A, I recommend putting Pot B at it's center position so you will have maximum flexibility for fine tuning the new adjustment.

Terminal Block Key

We are assuming you are using some type of combustion enhancement technology, such as an HHO system. There are many types of these including fuel warmers, fuel vaporizers, water mist injections systems, gas cracking chemical additives, systems that improve the respiration of the engine, etc. Any of these technologies may need an electronic enhancer to get the full mileage gains that the technology can provide. However, we don't recommend using this device, or any other type of electronic enhancer by itself. It will cause the engine to run out of spec, and this can be detrimental to the environment and to the health of your vehicle. But coupled with a valid and working combustion enhancement technology, you can reap rich rewards in reduced fuel costs and a reduced environmental impact of your vehicle.

With that in mind, as with any electronic enhancement, you will be going for the best fuel mileage. That's how you'll determine the final setting for your new MAPe. Do a rough setting as described above, and then drive for a tankful. Keep track of the amount of gas used to till the tank, and the mileage driven on the odometer. Note whether you mileage improved or got worse. If it improves keep adjusting in the same direction. If it gets worse, adjust back in the opposite direction. After you've tweaked it a few times, you will find the sweet spot that gives you the best fuel mileage.

As with any of our products, if you have trouble with this device, contact We will be happy to help you however we can to be successful with your project.

Special Situation Where a Different Output Pulse is Needed:

Nearly all frequency type devices, and more importantly, the computer inputs for them, are able to read the output of our device. It puts out a pulse of 0 to 5 volts. Even if your device puts out a lower pulse voltage, a computer input reading the pulses would still recognize a 5 volt pulse in nearly all cases. However, we have had one customer whose computer complained about the size of the pulses. We were able to cut the pulses down to approximately one half by adding a resistor. You can use a 220 ohm resistor between the frequency output port and the ground port on the MAP Enhancer. This will pull the pulses down so that they will be 0 to about 2.5 volts. Other resistances can be used to get different sized pulses. Again, this should almost never need to be used.

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