Comments on How to build a simple DIY fuel injection ECU controller

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Chazz 4 and 5 are not sequecial steps they are 2 different options. You cannot install both ways. The latter posses less risk to premature failure of the sensor due to feedback caused by adding resistance to the signal wire. The latter modifies reference voltage so there is no feedback to the sensor. The ECU can handle the feedback easily, and is designed to do so on that particular circuit.

Gorman, Their are third party experiments on this technology by the ASE that are over 20 years old, and suggest that the technology is valid, but they were under a lot of pressure back then not to necessarily endorse it as such. People were still getting fitted for concrete shoes when they built water cars back then. I could spend a lot of money having the united laboratory list these devices with a 50%-50% chance of success, and spend hundreds of thousands doing so, or I can put them on peoples cars and save everyone money right now. They work really well when properly manufactured, and professionally installed. I have ASE master technicians who install them, and would bet their certification that it works.

Step 4 and 5 contradict each other, is 5 or 4 we should be following?

Binder, I just read the posting from stevehaley about the MAF sensor. I also have a MAF in my 97 ford F150.I just finished building VR controler and want to install it.Will it work on the MAF sensor? If not is there a plan for an O2 sensor controler?

The MAF sensor works by heating an element in the path of incoming air. The computer gets it's reading from how much power it takes to keep the wire a constant temperature. It should work as long as you didn't put it on the heater wire which you may have done. The check engine light won't go off until the sensor input is corrected, and then you disconnect to reset the fault codes. Owing to the voltages, and manner in which the sensor works, and the computer reads it, the simple VR (variable resistor) controller might not work. In that case you will have to use an O2 sensor controller.

Binder, dose this work with a two wire Mas Air Flow (MAF) Sensor as well as the MAP? I found out my Subaru has the MAF sensor so I hooked it up to the only wire that had voltage and it did nothing except make the check engine light to light up. I tried to reset by disconnecting the battery and it will not go off. Any recomendations?

Binder, dose this work with a two wire Mas Air Flow (MAF) Sensor as well as the MAP? I found out my Subaru has the MAF sensor so I hooked it up to the only wire that had voltage and it did nothing except make the check engine light to light up. I tried to reset by disconnecting the battery and it will not go off. Any recomendations?

Binder, dose this work with a two wire Mas Air Flow (MAF) Sensor as well as the MAP? I found out my Subaru has the MAF sensor so I hooked it up to the only wire that had voltage and it did nothing except make the check engine light to light up. I tried to reset by disconnecting the battery and it will not go off. Any recomendations?

Binder, dose this work with a two wire Mas Air Flow (MAF) Sensor as well as the MAP? I found out my Subaru has the MAF sensor so I hooked it up to the only wire that had voltage and it did nothing except make the check engine light to light up. I tried to reset by disconnecting the battery and it will not go off. Any recomendations?

Binder, dose this work with a two wire Mas Air Flow (MAF) Sensor as well as the MAP? I found out my Subaru has the MAF sensor so I hooked it up to the only wire that had voltage and it did nothing except make the check engine light to light up. I tried to reset by disconnecting the battery and it will not go off. Any recomendations?

Do you have any recomendation of adjusting the city and hiway pots? Can a volt meter give an accurate measurement of expected results or optimum values? Thanks

OK what is the difference between a MAP sensor and a o2 sensor? Where is the MAP sensor located? If the o2 sensor controler is better why do I only see MAP sensor controllers on ebay?

This is a MAP sensor controller. Yes it lowers voltage, but you cannot simply step down voltage from the O2 sensor, wide or narrow band, it isn't that simple for the O2 sensor. The MAP signal however is just that simple. However in closed loop operation the ECU will constantly learn around this device (via the O2 sensor) so it must be re-adjusted periodically to compensate. An O2 sensor controller is much more desirable, but also much more complex. Almost all cars have wide band O2 sensors.(over 95%) If your O2 sensor has 5 wires it is narrow band. Mostly exotic cars are narrow band.

Your ECU controller appears to lower voltage and I have read that this would work for a Wide Band O2 sensor. A narrow band o2 sensor adds voltage uo to 1.5v. How do I find out which O2 sensor my cars have? That will dictate the type of ECU controller to make, yes?

Your ECU controller appears to lower voltage and I have read that this would work for a Wide Band O2 sensor. A narrow band o2 sensor adds voltage uo to 1.5v. How do I find out which O2 sensor my cars have? That will dictate the type of ECU controller to make, yes?

Thanks so much.

The ground side of each variable resistor has the 33K resistor on it to trim the 50K pot., or in other words give it more useable adjustment range by making it less sensitive. The schematic is drawn very simply to avoid confusion for the novice. The ground can be wired common with just 1 33k resistor on the ground side. The switch isolates 1 pot. or the other so it works either way. The ground symbol before the resistors in each diagram is a typo, don't ground before the resistor.

In your diagram in step 3, you have a ground on each side of the resistor? is this correct? Thanks

i have seen a different fuel controller that is put on the o2 sensor. They claim that by showing the O2 sensor that there is still oxygen that the contoller will work better. Is this the same type of controller you have here? What do you think about this?

This is very informative, thank you.

what is the best way to set the pot? which is high and which is low?