Cleaning Injectors, the cheap way

[jmgtp]

I want to do this the cheap way.

The Setup:
Meaning, clamp a piece of fuel injection hose to the feed of the injector, fill the hose with gm top end cleaner and then use regulated compressed air to force it through at around operating pressure. My thought was that I could use a 12v source to open the injector and allow for flow.

My question:
Is there harm to be done by 'holding' the injector open? It is designed to be rapidly pulsed, so is there a chance the coil can be damaged by holding it open? Will 12v right off a battery be ok? I don't want to fry them or damage them by holding them wide open for a minute. What if the seafoam runs out and I force some air through the injector... bad news?

This is for a set of used injectors that I want to give some kind of cleaning to, and also be sure that they dont leak down when there is fuel pressure but no signal to fire.

[WrathOfSocrus]

I'm pretty sure the injectors run on 5 volts like most of the engine sensors. It is a solenoid so holding it open isn't a big deal. Of course you would need the polarity correct in order for it to open, otherwise it will just try to force itself closed. I have used a regulated power supply on old injectors and I'm sure something could be rigged up with an old 'wall wart' plug such as what might be laying around with an old router or cell phone.

I have rigged up a spare fuel pump and run a very small setup where it just picked up and dumped alcohol inside a container. I have thought it would be very simple to put the whole LIM, fuel rail, and injectors into a large enough container where it could have the pump in the bottom and the injectors recirculating back to the pump. I already have a few top ends and rails around so I can save money there not having to buy any connections beyond some new O-rings which the injectors would need anyway. I have a 3500 fuel rail and a bit of hose that I would just have to find a way to attach to the fuel pump I have.

I guess you could put air though it but I don't think full blast 120PSI would be good for it. Perhaps with clean air at half that pressure it would work. My friend had bought a fuel pump when he had trouble with his truck but it turned out to be something different, and we kept it in case his does go bad. So I just used that to toy with a bit. If you ever intend on possibly using the setup more than once it might be an idea to keep an old pump or find someone parting out a car that will let you have it for cheap/free.

[Weatheralls Auto]

Colmen Lamp fuel or Varsal metal can.
Cut sqaure hole in top
cut a piece of square sheet metal just a bit larger
Drill two holes in center, 3/8" and 5/16"
2 pieces of tubing 3/8" and 5/16
braze/seal tube in square lid you made
neoprene hose on 3/8" tube to a fuel pump.
wire fuel pump with clamps for battery etc
5/15" & 3/8" neoprene for outside tubes.
Collect many different fittings for cars you work on or just your own if that is what you use it for.

Warm engine up, disconnect fuel pump, eng off, remove both feed and return lines, hook your connections up to fuel rail, connect battery connections (ooops fill your can with cleaner first) and start engine, I raise off idle, run till engine quits due to all the cleaner has been burnt of.

I made that about 20 years ago before we had cleaners at the dealer, I may even have bits and pieces of it around lol.

[robertisaar]

injectors are 12 volts... and if you try putting too much pressure to them, they will be hydraulically locked and WILL NOT open.

[pocket-rocket]

And as far as I've messed with electronics, solenoids don't care which way you energize them. They are an electromagnet attracting something towards them when hot which turns on a circuit by closing contacts, lets fuel flow by the pintle coming up off of the seat allowing flow, ect since they don't have permanent magnets in them (like a starter, which would turn the wrong way if hooked backwards).

[WrathOfSocrus]

Well I'm not very well experienced with it but the one old injector I messed with didn't do anything with the polarity the one way and made horrible sounds after hitting ~5.5V then again the injector sitting in a box for a few years may have played a role in it. I haven't gotten to the point where i need injectors cleaned very soon so I haven't put much thought time or effort into it.

[pocket-rocket]

I had a Tahoe I worked on have stuck injectors after the fuel pump quit working and the owner tried to start it a few times a day for a week... Getting dried, stuck fuel injectors to unstick in a CSFI mess in a Vortec 350 is an absolute pain...

Down towards the bottom and you will see what CSFI is and why I hate it.

http://60degreev6.com/forum/f102/behold-the-power-of-the-ranger-t40259

[Superdave]

If you run straight 12 to it it'll be fine as long as there is fluid flowing through to keep the injector cool. If you notice it starting to get warm i'd stop.



i run mine on 12VAC so they pulse at 60hz while in the ultrasonic cleaner.

[pocket-rocket]

I forgot to add. When working on that Tahoe I sat in the engine bay straddling the engine. They have a fuel pump test lead like my W body so when I needed fuel pressure I bumped it back up with the test lead. Then I used my 12v DeWalt cordless drill battery pack to pop the injectors open one by one to listen for fuel flow to see which were not opening. The 12v battery pack worked great for it once I shoved my DMM leads in it to make life easier for bumping the injectors with.

[60dgrzbelow0]

"This looks like a job for... "The FrankInjector"

LOL...

No but seriously... some of the components used in the making of this machine might be helpful... especially using the OTC unit instead of the straight 12 Volts with High Amps that might melt the electromagnetic coils if left in "WOT" too long...

http://s557.photobucket.com/albums/ss19/60dgrzbelow0/HOMEMADEEFICLEANER/

Oh... when using compressed air...install a metering gauge ahead of the fluid being pressurized...and don't exceed 43.5 PSI on the fluid pressure if possible... it is helpful to have an analog fuel pressure gauge interfaced between the fluid as it comes out the bottom of your pressure cylinder...and the feed to the injector(s)... so you can fine tune the pressure... B4 activating the EFI pintle(s). When the fluid evacuates... the pintles can still be activated to bleed off air pressure in time to turn off the source B4 damaging the innards of each injector.

[60dgrzbelow0]

Found another superb price and a great sale on eBay for the parts and pieces necessary for an "On-The-Vehicle" EFI cleaning procedure that would require very little modification from its intended A/C Flush purposes. This is the identical AC Flush Kit I employed when building "The FrankInjector Machine"...:

http://cgi.ebay.com/ebaymotors/FJC-2710-A-C-System-Flush-Kit-R12-R134a-R22-/350237821450?cmd=ViewItem&pt=Motors_Car_Truck_Parts_Accessories&hash=item518bcd0a0a

...but as always... the smart man will add an Adjustable Air Pressure Regulator fitted to the Air Inlet Side of this Aluminum Tank (only pressure safe when under 90 PSI inside!!!) and have a steel canister in-line fuel filter and a proper fuel pressure gauge between the air pressurized aluminum cylinder output line and the inlet Schrader fitting connecting to the Fuel Rail Manifold and NEVER exceed the recommended OEM Fuel Pressure ratings...whatever they happen to be for any particular vehicle. And Gentlemen... Please ...Always have a decent ABC Fire Extinguisher nearby when operating anything like this on a running vehicle....

[scott0999]

anyone have info on how to make a DIY back-flush setup? I have basically everything except that:

DMM, ultrasonic cleaner, injector pulser, bulk order of injector filters/orings/caps ect

[Superdave]

the exact pressure isn't too vital, i just set my dial to 50 when i check the spray pattern. they won't open up much past 70 PSI unless you increase the input voltage and current but that's pointless. Most of them draw around 1 amp each when held open with 13.8V and they will get hot fast with no fluid going through.. it's very easy to damage them.


My 60Hz rig burnt up, now i run a small DC motor with a cam that actuates 2 micro switches as it spins. I have the switches aligned so that it makes a nice pulse pattern.


DO NOT run straight injector cleaner or any other harsh cleaners through them without being diluted. For spray pattern tests i run WD-40 (you can buy it in non spray-can form), it would also do a pretty good job cleaning them as well. Remember that the screens on the input side is where most of the crud ends up and a few shots of WD-40 down in there will foam most of the stuff out.

[60dgrzbelow0]

anyone have info on how to make a DIY back-flush setup? I have basically everything except that:

DMM, ultrasonic cleaner, injector pulser, bulk order of injector filters/orings/caps ect

For the "Whole Nine Yards" on how to do this successfully... Please see this link to my Epic Post on this Project.

http://60degreev6.com/forum/showthread.php/42889-Home-Made-Fuel-Injector-Cleaning-Machine?highlight=frankinjector

Here is the link to my photobucket that shows all three generations of how to build your own Off-The-Vehicle "FrankInjector Machine" and nearly 300 images and 30 videos on the build(s). The attached image shows what all the aforementioned components look like when properly and safely assembled.

http://s557.photobucket.com/albums/ss19/60dgrzbelow0/HOMEMADEEFICLEANER/

Ordinarily... I would not disagree with Superdave on these issues... but from personal experience... inducing too much Fuel Pressure causes the Rochester Mul-Tech EFIs (P/N 17103007 and P/N 17108326) to hydro-lock or misbehave. Dave uses much larger injectors... so I bow to his experience with those and "Tooning" them.

If you want to skip all the agony of wondering whether these methods (or any others) have actually cleaned the filter baskets as clean as they can get...it might be easier to just replace them completely with new filter basket kits you can get off eBay for under $25.00. Here are the links to a video showing you how this is done in a very simple and straight forward manner and the link to the available product. (Only the portions describing how to R&R the Filter Baskets are relevant to the Multec designed Injectors). If you buy three V-8 kits... you will have enough to replace all the filters in four sets of 6 Cylinder EFI engines. Please notice the poor color and condition of the Multec Filter Basket as it comes out... That Brown Mung is what all the extra cleaning efforts being made are trying to extract...and often this is just an impossible job to do very well... especially when trying to dissolve and eject all that varnished on crap in reverse via The Back Flushing Method.

http://www.youtube.com/watch?v=V2sD5UsOnJs

http://cgi.ebay.com/ebaymotors/Rochester-Multec-Fuel-Injector-Service-Kit-8-Cylinder-_W0QQcmdZViewItemQQhashZitem53de0cc241QQitemZ360207663681QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

[Superdave]

I run mine at 50 minus pressure drop so it's pretty close..