Build A Map Maf Sensor

Below is a circuit for the MAP sensor and should work on most MAF
sensors that are voltage based.
I am not sure where I got this but whomever it was I am thankful.
I works very good and is really simple to build.

Parts are from Radio Shack

Parts List

  1. Multi-turn Cermet Potentiometer 1000 ohm
  1. LM317T Adjustable Voltage Regulator
  1. 220 ohm metal film resistor
  1. Small project box
  1. Small perf board
  1. Heat sink for Regulator
  1. SPDT toggle switch

I ran my hookup wires directly to my board connections and soldered.

I then Tied a knot in the wires and ran them through a hole in my project box and sealed it with silicone.

Mounted the box under the hood with a big dot of silicone.

The switch allows you to toggle between the factory 5.0 volt input and the adjusted input that you dial in. In case something were to go wrong with this MAP adjuster you could easily switch back and not be stuck somewhere. You could also eliminate it and use bullet connectors on the wires and just unplug the MAP output wire and connect it back factory mode till you can make repairs on your Adjuster.

The MAP sensor voltage adjuster has five wires:

*5.0v from wiring harness to left terminal of switch

*MAP sensor input from middle terminal of switch to MAP sensor

*Adjusted voltage from voltage adjuster to right terminal of switch (internal connection on board)

*12v supply to voltage regulator

*Ground wire from variable resistor (pot) to firewall

This is one I made.

Map Adjuster

Back side of board

Bottom View of Map Adjuster

Adjustment of the voltage from the adjuster is easy. Just hook up the positive lead from a digital multimeter to the adjusted voltage terminal and the negative lead to the ground. Read the voltage and adjust as required. Stock MAP sensor input voltage is 5.0v. If you turn the voltage higher than that, the air/fuel mixture will be enriched. If you reduce it to below 5.0v, the air/fuel mixture will be leaned.

Map Schematic

Map Schematic

Right Click on link below and select save as to download.

Map Schematic

Be Sociable, Share!

Technorati Tags: , , ,

Posted under

This post was written by Michael on October 28, 2008

Tags: , , ,

6 Comments so far

  1. admin November 18, 2010 9:43 am

    I can’t understand why you can not see the pics. They show up for me. You may have images blocked from the server by your browser.
    I would check your security settings in your browser options first. You can also download the schematics. The pictures just show how I built
    my MAF controller.

  2. Ron November 9, 2010 12:35 am

    I can’t see any pictures either!! Thank You for the article though !

  3. Michael February 28, 2010 6:35 pm

    Hey, I’m really wanting to make one of these, but I can’t see any of the pictures. Could you help me out? šŸ™‚

  4. Michael March 17, 2009 2:37 pm

    You are not actually feeding the sensor. You are feeding the ECU as the sensor is cut out of the circuit. And you need to reduce the voltage to in order to lean the fuel.

  5. Michael March 17, 2009 2:33 pm

    I am now experimenting with a resistor and pot in the circuit and it seems to work very well. You can dial it in until the engine will actually die. This is for a MAF sensor on a Ford.

  6. alex February 26, 2009 3:50 pm

    Wait a second! By using this princip you feed the sensor with voltage bigger than the normal one!
    1. you could burn the sensitive element down
    2. to confuse the ECU and to put mistakes into it.
    Isn`t it better to use a resistor?!
    I mean imagine + pole coming from the ECU, the active sensor`s end and -pole!
    If you connect a resistor between the – pole and the – itself you`ll increase the voltage given to the ECU in any instant with amount proportional of Rmaf(Qair)/R?!?!

Leave a Comment





CommentLuv badge

Spam Protection by WP-SpamFree

Security Code: