Home Made Fuel Injector Cleaning Machine

[Tbay99Venture]

Well after providing Robert I with some useless advice back on the ALDL thread, I was debating whether or not to post this. But here's a link of a commercial chip meant for operating injectors. They give a sample diagram with transistor specs and so forth, that's not the problem.

http://www.national.com/ds/LM/LM1949.pdf

What this shows is you end up getting into a bit of electronics fabrication to accomplish what everyone hoped would be just a simple fan-out from one injector to 6. You have to find a supplier, build up a circuit board and so on -- not a show stopper but it's cutting down on the potential number of folks willing to do so.

Now I say that the controller approach is needed since you're trying to operate the injectors as they would go in a real engine. A current pulse much higher than the device can sustain is required to get them opening quickly, and then you drop to a steady hold-open current. If you string all of the devices in parallel the feedback to the controller isn't going to be right even if you have a transistor (or bank of them) able to drive them. So it looks like there isn't a short cut to parallel 6 of them. You might be able to get clever and run two or 3 per driver chip and cut down on the parts count though.

Food for thought.

[bszopi]

In a typical GM ECM, you either have 2 (batch fire) or 6 (sequential fire) injector drivers. So, it would only make sense in trying to create a controller that you would need multiple drivers to run all the injectors.

[robertisaar]

In a typical GM ECM, you either have 2 (batch fire) or 6 (sequential fire) injector drivers. So, it would only make sense in trying to create a controller that you would need multiple drivers to run all the injectors.

IIRC, the 7727 and 7730 type ECMs have 1 driver... the second pin isn't connected to a second driver, just bridged from the first.

[bszopi]

They are essentially connected on the outside, but that doesn't necessarily mean there isn't 2 drivers inside the ECM. What is the other pin connected to on the board? It has to connected to something...

[robertisaar]

They are essentially connected on the outside, but that doesn't necessarily mean there isn't 2 drivers inside the ECM. What is the other pin connected to on the board? It has to connected to something...

i'm saying i think they are bridged INSIDE the ECM as well... it's been a while since i cracked one open though... the ludis recreation docs would probably show it though.

AFAIK, the 1227749 is one of the few MPFI ECMs that uses two drivers.

EDIT: here we go:

http://www.exatorq.com/ludis_obd1/p4xref.html#1227749

"1227730 w/ one missing quad driver, w/ additional injector driver FET"

so either the 7749 has 3 injector drivers and the 7730 has 2, or the 7749 has 2 and the 7730 has 1.

[bszopi]

AFAIK, the 1227749 is one of the few MPFI ECMs that uses two drivers.

EDIT: here we go:

http://www.exatorq.com/ludis_obd1/p4xref.html#1227749

"1227730 w/ one missing quad driver, w/ additional injector driver FET"

so either the 7749 has 3 injector drivers and the 7730 has 2, or the 7749 has 2 and the 7730 has 1.

Too bad the schematic doesn't help any, since its the same one for both part numbers... http://www.exatorq.com/ludis_obd1/1227749sheet7.gif

[robertisaar]

mmm.....

i could probably pop the connectors off of the wife's GP, and do a resistance test between the two pins. low/no resistance would be a good indication that they are indeed bridged internally.

[60dgrzbelow0]

P-R ... Please forgive any notion that I might expect anybody to shell out any bread to further this project... I think the most I was hoping for was for someone to dope out a simplified schematic that included a breadboard layout and a decent components list that I could buy and build using Radio Shack parts, or their like. I am very sorry for your present employment dilemma and hopefully temporary financial straits... FWIW, I spied this site that, just in case you have not tried to scour this particular venue, you might find something that suits your job demands:

http://jobs.oodle.com/careers/elkhart-in-area/

On the subject of "Food for Thought" regarding the need to reduce the number of injectors from the complete load of six (6) down to three (3) for better functionality... that line of thinking has already been eaten, chewed and digested well back in this epic post ...somewhere contiguous with the helpful suggestions by Superdave and Roberisaar concerning the use of an ATX power supply...when I discovered that in order to make all six work during the cleaning, it took the use of two OTC devices as the necessary evil to make them fire and clean reliably.

Nonetheless... I am pleased to see more dialog happening about the possibility of some "Doodad" being created that works both independently and in conjunction with "The FrankInjector Machine". As a side bar issue concerning the need to maintain the quality, cleanliness and re-usability of what ever EFI cleaning fluid is used in the machine... I have been looking at yet another "Mousetrap" that will not only be small enough and discreet enough to provide metered air pressure to the Aluminum EFI Cleanser Pressurization Cylinder... but also allow for the filtration and elimination of atmospheric water from contaminating the re-cycling fluid. This item shows some promise in solving this problem, albeit a relatively small one because unlike the use of an air compressor for something like spray painting, where a large volume of moisture laden air gets in close contact with the fluid being pressurized...The FrankInjector simply has air pressure applied on the top of the liquid cleaning solution and remains essentially static while doing its job of "pushing" the Chevron Techron through the fuel filter and down through all six (6) EFIs. But still... I would like to avoid contaminating what is already designed to be a naturally hygroscopic cleaning solution that is attracted to moisture by its very design. (No sense in "Watering Down" the cleaner any more than is necessary). Here is the item(s) from eBay:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=330430709325&ru=http%3A%2F%2Fshop.ebay.com%3A80%2F%3F_from%3DR40%26_trksid%3Dp4712.m570.l1313%26_nkw%3D330430709325%26_sacat%3DSee-All-Categories%26_fvi%3D1&_rdc=1

[pocket-rocket]

I appreciate the thoughts, really I have a line on a job at Keystone RV. I'm hoping things work out because from the looks of it that place looked like a good place to work and has always been known as a place that makes good money. Sad thing is, if that place doesn't work out (because it's pretty much been my only line on a job lately) I'm going to end up losing my house, which is going to screw the people we are renting from because their plumbing business isn't doing so hot at the moment either. In reality, this area still really really sucks as far as jobs go. Thanks for the link to that site, but sadly as far as "real" experience goes (the way the real world sees it) I have none. I've got my A+ and Net+ in computers, but that amounts to about as much as having a pair of wire strippers and calling yourself an electrician.

I wish I could whip up a schematic, but I haven't done anything other than simple stuff lately and would have to go back to my books to pretty much relearn some things :/

[robertisaar]

but that amounts to about as much as having a pair of wire strippers and calling yourself an electrician.

wut? you mean my crimp connectors don't work on computers?

if i knew how the components worked and had pinouts, i could make a decent diagram, if this is any indication of good.

http://www.robertisaar.co.cc/web_images/max232_aldl.pdf

[pocket-rocket]

It's good, but the (chassis) ground symbol looks like:



and an electrolitic capacitor looks like:



Otherwise the symbol for a capacitor is more like:



But yeah, If I were doing something with your circuit, I would have no problem reading it

[robertisaar]

But yeah, If I were doing something with your circuit, I would have no problem reading it

that's what i was looking for...

[60dgrzbelow0]

Thanks Gentlemen... But sadly for me...and oddly...just like the great Michael Faraday... I might have the same urgent need to be creative and solve problems involving these powerful and invisible forces, but for the fact that we both share the lack of a deeper mathematical understanding and the requisite electronic acumen that you all seem to posses allowing you the ability to look at a diagram such as the one Robert I. Saar just shared and understand it completely. When I gaze at it, I see nothing more than what amounts to a pile of arcane squiggly lines and Hieroglyphics to magnify my lack of understanding. And even if I can spot a series of One Microfarad Capacitors and a few Resistors here an there... I am constitutionally incapable of translating that "special road map for Electrons" into the individual parts that must be aligned, connected and finally... soldered into place...and then test to see if it even works. More importantly... when it comes to electronic things... on the grand scale of finished pieces...I don't have the faintest idea WHY they work... or WHAT they do while doing it. The only thing that seems to work with me is to see actual pictures of each part...and then seeing them arranged properly so I can simply "Monkey-See-Monkey-Do" them together with a small soldering iron. I'm sorry for this vast and empty space in my body of knowledge... I wish it were otherwise. The only reason I have been able to build things in my life is because what I have lacked in fundamental and theoretical understanding... I have tried to make up for with the sheer force of my determination and a willingness to try things out...and fail at them...and yet... keep trying again and again until I can get things to work. It is often so very primitive and I sometimes feel like the Nine Pound Sledgehammer vs. that Thin, Brass Screw that keeps coming loose from the hinged arm on my eyeglasses when attacking these issues and searching for solutions. And so... I have such a deep and abiding respect and real envy for those who can dope out entire electrical and theoretical problems... and find their perfect solutions ...right there... inside their heads.

[60dgrzbelow0]

This is a fairly universal set of Multec EFI "O" Rings and Spacers, etc, covering most of what we drive... and since its nice to be able to buy them dirt cheap... these are worth look ... I like to freshen up the ones I use on "The FrankInjector Machine" every once in a while, too.

http://cgi.ebay.com/ebaymotors/84-00-GM-Fuel-Injector-O-Ring-Kit-O-Ring-Lot-Assortment-_W0QQcmdZViewItemQQhashZitem562bd58368QQitemZ370102600552QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

[60dgrzbelow0]

Just a new little wrinkle in the aspect of improved portability aspect of using "The FrankInjector Machine" in remote places that are not near electrical power supplies... such as rural farms or places where finding the means to support the need for air compressors to maintain a constant or metered air pressure inside the cleaning fluid supply cylinder are either impossible or impractical... Keeping in mind that the OTC units can be powered by the car/truck/SUV 12 Volt Battery...

On the wings of having recently to make certain that all of my HVAC SilFos brazing of all copper tubing and fittings remained free of internal water, oxygen, air contaminants and carbon flaking, etc.... I obtained a small cylinder (Size 20) that holds around 2,000 PSI of Dry Nitrogen and the necessary high to low pressure regulator to manage the flow of this inert gas at between 3-5 PSI during actual brazing... and later up to around 150 PSI for pressure testing the HVAC system and using "Predator Blood" glommed on all the fittings and joints to reveal any potential leaks or bad brazing spots prior to the infusion of any refrigerant gas into the system. It occurred to me that this gas would also be a perfect solution to the problem of using regular bench shop air compression of water saturated atmospheric air that over time and many repeat cleaning cycles, tended to degrade the purity of the filtered and re-filtered Chevron Techron Cleaning Fluid with water. Since the amount of pressurized gas necessary for a cleaning cycle is small and in fact almost static once the proper fuel pressure is adjusted... one cylinder of Dry Nitrogen would serve to function very well for a very long time in this application and very well extend the life and utility of the filtered Cleaning Fluid as well. The use of Dry Nitrogen in this manner essentially makes "The FrankInjector Machine" completely portable!

But as a Safety Side Bar...This is NOT a trivial issue...

I want to discourage any use of any other type of highly pressurized explosive or flammable gases that are not completely inert and the need to use a proper and definite purpose step down set of Pressure Manifold Gauges to avoid detonating the Aluminum Cleaning Fluid Cylinder by accidentally instantly over-pressurizing a cylinder designed to handle only 90 PSI with 2,000 to 3,000 PSI and risk death or serious injury by trying to accomplishing this without proper gas flow regulation. Trying to control and limit the release of any gas from any highly pressurized cylinder by hand on the main valve is akin to pulling the pin on a hand grenade and then trying to put the pin back in after its too late...

(Just watch the closing scenes in the movie "Raising Arizona" with Nicholas Cage if you want to see what will happen...)

http://www.youtube.com/watch?v=4wTT1Gz8Qeo