Wondering why you couldn't use a fuel pump for a WI setup? me and my uncle were sitting here talking about it why couldn't you use it?

 

Most fuel pumps have the motor/windings/etc. running IN the fuel to cool them. Fuel is nonconductive, water you would use is conductive (Chemists: I know completely deionized water is an insulator but that's very much a lab oddity and not usable in the real world). I would imagine there's internal corrosion issues as well, similar to the use of fuel injectors with water. Even the stainless ones are reported to internally rust up in a couple of days. Please don't misunderstand me, this is no flame; thinking out of the box and coming up with thought experiments is awesome!

-Mike

 

I'm currently doing some testing with a fuel pump and injectors. I'll let you know how it goes; I've only run them twice, and a week apart. No rust yet. There doesn't appear to be any issues as far as shorting inside the pump. I've run up to 70 psi and the current draw isn't out of the ordinary. The corrosion issue I'll understand better with time. I think the reason a lot of people run other pumps is that they want more pressure than typical fuel pumps can provide. I'm still evaluating whether the spray pattern I get out of the injectors at lower pressures is acceptable. FYI I'm using new 2004 cobra mustang injectors and a summit racing inline pump and an SX FPR with windshield washer fluid.

 

pmrobert. I understand. i thought that the fuel helped lubricate the pump thats why i thought you couldn't use water. I never gave the rusting/ corrosion a thought and thats common sense lol. if you ran meth or alky would that help with not corroding so fast? seems like pure water would make corrosion faster. Also what do you mean by conductive?

Maximum. I have like 3 or 4 walbro 255's laying around so i was going to try and use one along with a a n/a rx7 injector or turbo one i have a couple rc injectors laying around also what CC injector is the cobra injector? how do you have your system wired up? Im really interested in how your setup is.

 

My setup is pretty customized. The cobra mustang injectors are 440cc. Two of them can supply about 21% of my fuel injectors' capacity. I picked them because they are a relatively new design so it is likely that they were intended to be compatible with ethanol and by extension might hold up alright with water/methanol mixes but that remains to be seen. I had a custom rail made and mounted them in my greddy elbow. I am driving them with a microprocessor and a driver circuit I put together. I'm hoping to do flow testing with washer fluid soon so I'll report after I get that done. It's still going to be a while before I install the system in the car - I have plenty more bench testing I need to get done. Maybe at some point I'll write a post about the whole setup but I'd like to get a little further with testing to see whether injectors are worth using at all. I just haven't found enough definitive information about how well they work with water/methanol so I'm doing my own.

If you just want to run a simple on/off system (not progressive) you could just power an injector with 12V directly but obviously you'll have to do some fab work to get a rail together. I encourage you to do so and share your results.

 

well i would like it to be driven setup not just a on off switch. i would like it to come on at let say for instence. 5psi-25 psi but at 5psi its only running at 25% then ramps up to 100% threwout the power band. you get the idea... wonder how i can make this setup. maybe with a old ecu or something idk im going to ponder on it

 

Conductive== electrically conductive. It doesn't flow enough electricity to cause a dead short but rather causes electrolysis, a destructive process that occurs when dissimilar metals are placed in a conductive liquid even without any outside applied electricity. Boats have a massive problem with this, that's why there are zinc plates, etc., placed on boat hulls and engine lower units. Zinc will sacrifice itself so the aluminum and steel last more than a month or so. Maximum, that's very interesting! Let us know how this holds up. The info I was working from involved Ford flex fuel injectors from a dual fuel Ranger which are stated by Ford to be stainless. They reportedly lasted a week. If you've found injectors which will last in water, that would be great! It would be so much easier to map a precise % of fuel/H2O using, as you already apparently have, a uprocessor.

 

just startn - You're describing a progressive system and your options for putting one of those together are to build a system like I have, buy an off-the-shelf progressive AI system, or use an ecu that has an auxiliary output.

pmrobert - Thanks for the input. I'll let you know how things go. There is no visible corrosion on the injectors as of right now but I haven't had a chance to run them since the last time. However if I do get a chance to run them and they work again it will at least prove they last longer than a week! What is your source for that piece of information? I'd like to get a look at it because I couldn't even find anything that specific. I was considering FFV injectors but I heard that most of the more recent injectors had the same design and materials used. The reason I'm building my own system with a microprocessor is that it allows me the flexibility to have all the functions I need. I'm not going to run a map per se, I'm going to have it determine AI injector duty cycle based on a percentage of fuel injector flow. I've heard that some of the newer units have adopted this method since I started working on it. Makes the most sense since it's a heck of a lot easier to tune.

 

I run microtech co there should be a AUX. port that will run this? but i just don't know how about how to do it all set it up in the system or anything. idk im goign to have to start putting my brain storms into action and figure things out

 

I'm not horribly familiar with standalones other than PFCs but I wouldn't be surprised if you had an auxiliary output on your microtech. If that can output a pulse width modulated signal related to your fuel (gasoline) injector duty cycle, it can definitely drive your injector. You may need a simple circuit to supply the current to them, but that's easy. You can copy such a circuit from the megasquirt schematics.

 

i know it has aux outputs i just don't know how to go about using em with this

 

http://www.megamanual.com/ms2/pcb.htm scroll down to the output injector circuit.

 

ic ic. i still just am mind fragled lol

 

FYI I ran the pump and injectors again yesterday after they had sat for a few weeks. Still no signs of failure. Plenty more testing awaits though.

 

a Bosch 044 variant (909) powers my 100% meth system. installed last august. i run it at 107 psi w a return line & Weldon pressure regulator.

hc

 

Good info but I think running any percentage of water through the pump is what makes things questionable in this thread.