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View Full Version : Voltage versus fuel curve



DrBrown
10-20-2008, 01:18 PM
I had built a megasquirt ECU for my old car, which is a totally custom home built stand alone engine management system so it was controlling everything from my spark angle to the fuel curves. I noticed that when my battery was low on voltage due to a faulty alternator my car ran super rich to the point of stalling just from flooding it. So when the voltage dropped my ECU made it run richer. With an OEM ECU in a car would it result the same when the voltage to the computer drops? The reason I ask at all is if the alternator has this additional load from the HHO cell will it reduce the actual voltage the car's ECU sees, possibly causing a loss of efficiency or richening the fuel curve? I wasn't sure if the battery will still have 13-14v even if the alternator cant keep up or not. It could be why some folks dont have as significant of gains. Possibly having a weaker alt could reduce the effectiveness?? Just thinking out loud! :)

Keith's Garage
10-20-2008, 04:33 PM
If you have a weak alternator that can't keep up with the HHO generator, then there will be electrical issues. As far as that being why some are not getting the gains, I don't think that is why. The problem most are having is caused by them not using the computer to lean out the motor. When HHO is introduced to a motor, the exhaust becomes more oxygenated, which in turn makes the O2 sensor tell the computer to richen up the motor. In order to realize MPG gains, one needs to enhance at least one of the sensor signals.

DrBrown
10-20-2008, 04:48 PM
In order to realize MPG gains, one needs to enhance at least one of the sensor signals.

Even people with EFIE's and like devices are still not realizing gains though. That is what I am talking about. I think some ECU's are just programed entirely different than others and have different closed loop settings. But in general I do agree that if you aren't manipulating the o2 voltage you will probably not have luck unless its a very simple OBD1 or older engine.