I have been led to believe that I NEED a MAP Sensor Enhancer.
If you have a MAP sensor then you NEED a MAP Sensor Enhancer if you want to optimize fuel economy.
Not only will a MAP Enhancer ‘correct’ for manifold air pressure loss if using a fuel saver like the HyCO 2A, it will help the computer correct ignition advance for fuel savers like the HyZor (BG or HHO addition).
I had read somewhere that a simple potentiometer needed to be place on the MAP sensor. I cannot find that document for all my trying and cannot remember where I saw it. My MAP sensor has 3 wires. One ground, one 5watt power and one that adjusts voltage based on vacuum. Which wire do I attach the potentiometer to?
It’ll be 5 Volt power (not 5 watt). That’s the Power Supply voltage. The ground is ground. The signal wire (varies voltage) is where you want to apply the potentiometer (usually about 15K ohms). You put the pot. in SERIES into the signal wire.
The MAP sensor is a variable resistor that REDUCES the voltage signal going to the ECU (via the signal wire) by increasing resistance as the vacuum increases (lower absolute pressure). Here’s an example chart:
Lower pressure (supposedly) means there is less air (and or lower engine demand for fuel) so the ECU cuts back on fuel (and retards the ignition timing) to compensate.
What this means to you is that you can ‘fool’ your ECU into reducing fuel by ‘modifying’ the voltage signal going to the ECU.
More resistance (in series) lowers the voltage, which lowers the fuel consumption.
So I recommend wiring your potentiometer so that clockwise LOWERS resistance (more fuel) and counter-clockwise INCREASES resistance (less fuel).
You can buy assembled MAP Enhancers on eBay for cheaper than you can buy the parts, unless you already have them laying about.
I haven’t seen anything (at Eagle-Research) about a MAP Sensor Enhancer.
I do not currently sell a MAP Enhancer because they are being sold on eBay for less than I can build them. Usually they are just a 15K variable resistor (for variable voltage MAP sensors).
I have a 1989 Ford F-150 4 X 4 with a 302 cu. in. engine. The MAP sensor on a Ford does not send a voltage signal back to the computer but a Digital Frequency Signal. You cannot measure a voltage drop on the signal wire. You can only measure a frequency change.
The Frequency varies from 100 Hz to 156 Hz at my elevation. I guess it is up to 159 Hz at Sea Level. The way it works is, as the vacuum increases the frequency drops. It varies based upon how many inches of vacuum in the intake manifold. That frequency signal from the MAP Sensor is also calculated and factored in by the computer to regulate how much fuel it pumps through the fuel injectors.
The truck only has one (1) Oxygen Sensor and I have purchased the kit here for that.
Thank you 🙂
Do I need the MAP Sensor Enhancer in addition to the EFIE?
This other place is saying i need both and they have a special one for the Fords that have a digital frequency signal but I don’t think they are adjustable.Their info says they are “set and forget” as it was stated on their site. That doesn’t seem like the optimum solution to me.
It’s not. It should be adjustable so that you can balance gains and performance for your vehicle and application.
If I do NEED the MAP Sensor Enhancer is there a way I can send my own digital frequency signal down that line to the computer and bypass the sensor completely?
Yes you can, but it wouldn’t be wise. You’d lose the whole reason the MAP sensor exists, which is to optimize air:fuel ratio and ignition timing ‘on the fly’ and automatically. Best to use a ‘correction’ circuit.
Could I just use a low, VERY LOW frequency generator? That way I could dial in different frequency settings for different driving conditions and circumstances. Does anyone have an idea about how to make this work or if it would work?
It would even help if I could just somehow put a circuit in-line that would raise the frequency by 10 to 15 Hz or more if possible. Any ideas?
Actually you want to LOWER the frequency because you want the CPU to ‘see’ a higher vacuum (less pressure) and yes, I have designed such a circuit. You put a 15K resistor in the power line (positive feed) leading up to the (frequency based) MAP sensor. This lowers the voltage that the sensor is getting and slows down the output frequency. But this solution also lowers the MAP sensor output signal voltage which MAY, in some cases, cause the CPU to think that the MAP sensor is bad.
So you add a ‘voltage pullup’ P-channel MosFet to the circuit, wired thus:1. MosFet Source is connected to the positive wire going to the MAP Enhancer BEFORE the above resistor.2. Signal the MosFet gate with the MAP sensor output signal. 3. MosFet Drain then goes to the CPU (in place of the original MAP Sensor signal).I like this particular MosFet for this application.http://www.mouser.com/Search/Refine.aspx?Keyword=IRFD9014YEAH! problem solved, you now have a simple low cost solution for frequency based MAP sensors.