Home Made Fuel Injector Cleaning Machine

[robertisaar]

well, that's a neat trick.

[Azrael]

Dry nitrogen is very cheap and readily available too. The aviation industry uses it everywhere. But yes, very dangerous. A number of people have killed themselves filling tires with high pressure bottles and not paying attention.

[ollopa]

Okay... As much as I am seriously interested in this Gentleman's idea about creating his own OTV means to actuate and variably control Electronic Fuel Injectors... I'm a bit frustrated with the idea that he has not addressed this matter openly in this forum thread where he and others would have a better chance of interacting about what he is attempting to do. Instead, he is trying to accomplish this in the vacuum of sending and receiving personal emails to me on the matter. The attached screen prints are of his latest communique, stressing that in all matters relating to my end of this project... and my response to his request.

The man may already be a member here... but since I have no way of knowing or confirming this to be the case... I made my latest ( and last) request for him to join us all here and try to help him with the development of his unique EFI "Driver" device. I will not be interacting on this matter unless it takes place on the site of its original posting: www.60degreev6.com. There are many of us here who might enjoy working with this engineer in making something that I would very much like to try out on " The FrankInjector Machine" and end the problem and complications of having to employ two OTC units to get the job(s) done correctly. It has been a very long time since this thread was started in order to answer this very specific question.. .and it has not been solved yet... But I think this fellow is very capable of doing the job...and I am hoping he will come here and share his ideas with all of us and complete the last and final necessary piece of work.

Hello,

I'm the person referred to in this post. I emailed 60dgrzbelow0 a few months ago after reading this thread. I thought we should get in touch since we have overlapping interests and I intended to do some work on the electronics end of this project. I'm not sure what I was thinking at the time. I was excited about my own plans for my piles of injectors, but also empathetic to 60dgrzbelow0's frustrations with finding a cheap stimulus for driving the injectors. I felt the way a plumber must feel when people helplessly complain about leaking pipes and faucets. To the plumber, changing an O-ring or soldering copper pipes is a routine and trivial task. To electronics guys, driving solenoids is also a fairly trivial task and that OTC device is way overpriced and unimpressive. So I fired off a message.

The only catch is that I have been involved in another endeavor and I knew I would have to put all distractions such as this on hold until... Well.. Now. I thought I made that clear, but apparently it was only clear in my mind and so my absence here was taken the wrong way. I didn't want to post in this thread, get a bunch of people excited, then disappoint while I was off doing something else for a few months, and then finally return like a reborn savior to deliver on my promises. Too late now I was a little shocked to see our emails made public and a little upset that my address was not redacted. In fact, I sent my original message through this board and not directly via email. The board sent a message with my username and also the email address I used to register here. Although we corresponded on that address, it is not the one I would prefer to use for this project. My original message contained my preferred correspondence address, but apparently the forum here had already used my registered address as the reply address.

So, grievances and explanations aside, let's get this ball rolling.
I have several sets of used fuel injectors of dubious size and health. I would like to clean them but I would also like to characterize them for EFI tuning purposes. I'm interested in flow rate at various voltages as well as opening time and flow rate/consistency at very short pulsewidths. Some of what I want to do is not at all necessary for simply cleaning injectors, but there really isn't anything to be gained by stripping features out of the driver. The hardware platform I would use would be virtually identical in either case.

We need a power supply, output driver, and pulse generator.
The power supply could be a car battery, a computer power supply, or a high quality bench supply. Small wall-wart adapters are not going to cut it. Peak currents should be on the order of a few amps. This is no problem for an off-the-shelf power MOSFET, but it can load down a cheap power supply. Most people here will probably wind up using an old computer power supply. For myself, I am considering designing a variable switching supply for my voltage characterizations. This will be a separate project, though, since it does add cost and complexity.

The output driver can be any power transistor. BJTs would work but are a poor choice due to their high loss when used as switches. They would just heat up and waste power/further load the power supply. IGBTs are a common choice for this sort of thing, but they are expensive and they do not offer many advantages (if any) over MOSFETs at this power level. It's not worth it, IMO. I would not use any type of relay, solid-state or otherwise, for this application. Relays are large, slow, lossy, expensive. Relays offer electrical isolation and bidirectional current--neither of which is important for this project.

We have a couple choices for pulse generation: 555 or a microcontroller. Analog circuits using a 555 are cheap and simply, but not flexible, extensible, or stable. A microcontroller is still inexpensive, extensible, and stable. It's a no-brainer for me--I will use a microcontroller. I want to have precise control over duty cycle, frequency, duration, etc. I want to be able to vary these parameters whenever I choose. Changing these parameters with a 555 means redesigning the circuit. With the uC, it means loading a new firmware.

Now it is possible to drive all injectors off of one transistor, two transistors, four, eight, etc. It's possible to gang transistors in parallel. Let's explore that for a second. I'm flatly against combining transistors in parallel. Saturated transistors in their on state will have slight variations in their conductance and so the current flowing through two transistors in parallel will be unbalanced. You need to include resistors in the design to satisfy the gods of physics or else Bad Stuff can happen. It's better to just spec a bigger transistor. It's nothing to find 400V/25A transistors, which are way overkill for this project.

It's also possible to assign each injector its own relatively small transistor and drive them in batch or in sequence. I'm leaning towards this. Small transistors are less than a dollar a piece, so cost is not a concern. Driving the injectors in an interleaved or sequential pattern will also reduce the impulse load on the power supply. It may be possible to use much smaller and cheaper supplies in this way. The cool thing about this arrangement is that you can choose to drive all injectors simultaneously, in batch, or sequentially at-will and without altering hardware. It's a more extensible design, IMO.

For the user interface, it could be just some buttons and switches like the OTC controller, or it could be a rotary encoder (knob with a pushbutton) like what was in that youtube video. I've got both in my junk drawer. For an extra $2-$5, we can add on an LCD display from a wholesaler. I'm going to use an LCD for my device, but it does not have to be mandatory.

With a microcontroller at the core of this device, there should be room for oddball features if anyone can think of something.

Well that's pretty much it for now. I have already ordered and received parts for prototyping and I'm now ready to work on this project actively. I'm interested in discussing the features you guys want as well as the user interface and what type of enclosure to house the electronics in.

Let's buzz some injectors
-Rick

[60dgrzbelow0]

Rick...

Welcome...

"My Profuse apologies... Great Buckaroo Banzai..." For posting the personal email information... But in the absence of anything in your original message not to do so... and since I had already broached your idea to the forum... I was held hostage to "make good on delivery" of this idea you had in mind to do. The people who populate this forum have a rich and unsavory taste in their mouths when promises are made that cannot be met.... especially when so many are waiting with baited breath to get things like "Full Roller Rockers" and the like that saturate the V-8 markets but leave the V-6 markets wanting. For my part... I have designed and delivered on each and every phase of the development of "The FrankInjector Machine" and shared everything completely with all members here...warts and all. My posting of your email was done to prove to everyone that you really did exist and that I have made good faith efforts in encouraging you to come here for all discussions... It is here that you will find your client base and potential customers... and whatever you come up with... will work independently of... but also nicely augment the analog cleaning gear creation that has come from my end. So... Welcome... "TRON"... We simply can't wait to see your first working Prototype....What will you call this creature? "THE TRONJECTOR"...... ?

[60dgrzbelow0]

There is a parallel posting concerning a simplified method for ON-THE-VEHICLE EFI Cleaning that merits a link here... just to avoid having to redundantly list in here what is being covered there that cross relates to this project:

http://60degreev6.com/forum/showthread.php/45708-Cleaning-Injectors-the-cheap-way/page2

[60dgrzbelow0]

Brad.... Just a heads up...in case you get inundated with hits on the forum...

This is a message I posted on a another Q&A site in response to the question "What is the Best Way to Clean Electronic Fuel Injectors". I have listed the point of origin as this forum and provided links to my photobucket in the message... so I will be curious as to the responses from the general public inquiries out there...seeing as how our group is uniquely interested in V6 issues... Here is the link to my response there:

http://www.howtocleanstuff.net/auto/mechanical/how-to-clean-fuel-injectors/comment-page-1/#comment-57660

EDIT:

Ahhhh... Guess what... the Mods at this site muct have reviewed, got scared and then bounced my posting there... I was looking around at the "Advertising Bling Spots" all over the page...and they are being supported by companies that do commercial, Off The Vehicle EFI cleaning... so apparently they didn't dig the idea of "The FrankInjector Machine"...nope... not one little bit! It would seem they don't want people actually having control over when and how to clean their EFI systems.... Hmmmmm... Well... F*ck Meee!

[robertisaar]

"just about the only gasoline you can purchase in Mexico, Pemex, is notorious for not only skimping on detergent but also selling dirty (and even watered-down) gasoline"

note to self: avoid mexico.

[60dgrzbelow0]

For you Turbo Enthusiasts...some recognition and interest (and sarcasm) in "Frank" can be found here...

http://www.realhomemadeturbo.com/forum/index.php?topic=9974.msg168178#msg168178

[bszopi]

My thought is, the more traffic to the site, the better!! In the past 12 months, we've used less bandwidth than we are allowed in like 2-3 months. So yeah, bring 'em over!

[robertisaar]

"starting with the prototype version called "The Heat Seeking Moisture Missile Receptacle""

LOLOL....

[60dgrzbelow0]

"starting with the prototype version called "The Heat Seeking Moisture Missile Receptacle""

LOLOL....

Oh...You mean... "The HumpInjector Machine"...? LOL .......... R.I.S. ... One can be a a serious and inventive person...AND still... maintain an incorruptible sense of humor...Yes?

They fooled me into thinking there site was exclusively for car stuff... but go there and look around... but stop drinking your morning cold milk and eating those DD Oreos...or you will suffer the pain of laughing so damned hard that it shoots out of your nose! Damn that's funny...but DAMN THAT HURTS!!!!

http://www.realhomemadeturbo.com/forum/index.php?board=1.0

[60dgrzbelow0]

Ahhhh... Guess what... the Mods at this site must have reviewed, got scared and then bounced my posting there... I was looking around at the "Advertising Bling Spots" all over the page...and they are being supported by companies that do commercial, Off The Vehicle EFI cleaning... so apparently they didn't dig the idea of "The FrankInjector Machine"...nope... not one little bit! It would seem they don't want people actually having control over when and how to clean their EFI systems.... Hmmmmm... Well... F*ck Meee!

http://www.howtocleanstuff.net/auto/mechanical/how-to-clean-fuel-injectors/comment-page-1/#comment-57660

[ollopa]

Well there hasn't been any input on my end of the project, so I'll just check in with where I'm at and what I'm thinking. I just got a wideband O2 sensor and am in the midst of fine tuning a heavily modified engine for a 302->351 swap, so I have been a little distracted after all. I grabbed an injector and threw together a MOSFET driver for it. It works great, so I've been thinking about the digital drive. I know I can get 1ms resolution without any trouble, but I'd like to try and get 0.1ms or 0.5ms resolution for some rudimentary injector characterization.

Driving all the injectors simultaneously would be really harsh on the power supply, so I'd like to have some options for driving patterns: simultaneous, sequential, and bank (batch). Sounds a bit like EFI options The tradeoff here is that the more injectors you drive at one time, the sturdier the power supply you need, but the fewer you drive at one time, the longer it will take overall to fire all the injectors. It's only software, so why not make all the options available and let the user decide, right?

So we'll be able to select the number of injectors connected from 1 to 8, and the drive pattern of sequential, simultaneous, and bank. Bank drive will have a couple different configurations depending on the number of injectors connected. For example, if you have injectors then you could fire four banks of two or two banks of four (2/2/2/2 or 4/4). If you have 6 injectors, you could configure banks of 2/2/2 or 3/3. Whatever your power supply can handle and whatever you personally like.

Duration will be programmable and will have a couple modes. You can either specify the number of pulses to send or go into continuous mode where you push a button to start sending pulses and it will keep sending until you push the button again to stop.

I'll post a video of the prototype this weekend. I haven't built a FrankInjector yet so I can't show injector spraying, but I'll be able to demo the user interface and let you listen to injectors clicking.
-Rick

[robertisaar]

something to keep in mind maybe?

i read that the multec injectors take around ~400uS or pS to open fully, i can't remember which, and if that was meant for the high impedence or low impedence injectors....

[ollopa]

That must be low impedance injectors and uS. I haven't given much consideration to low-z injectors yet since I don't have any for testing and they are less popular. There are a few options available, though: I could use hardware PWM to drive maybe two low-z injectors at a time, some current-limiting series resistors could be added to the harness, or I could make an external peak and hold driver board add-on. I'm leaning towards the resistor option right now since they are really cheap and get the job done without any fuss.