Cleaning (and Rebuilding) Your Injectors

[usury]

When I removed my cam housing and intake manifold, naturally the fuel rail and fuel injectors needed to come off, too. It's a good time to clean them and replace the rubber bits and filter screens.

I used my ultrasonic cleaner (iirc around $50 from eBay a couple years ago - very handy, and seemingly nicer than the more expensive version currently sold by Harbor Freight), bathing the injectors in "B12 Chemtool Fuel Injector Cleaner" (from my Friendly Local Auto Parts Store).

Since the injectors are much smaller than the capacity of the ultrasonic cleaner, I used a small disposable food storage plastic "tupperware" to contain the injectors and "B12 Chemtool" and placed that in a bath of hot water in the ultrasonic cleaner, which allows you to use much less B12 Chemtool and still get the same results.

Injectors in Cleaner 01

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B12 Chemtool Injector Cleaner

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Injectors in Cleaner 02

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I think I ran them through two eight-minute cycles in the ultrasonic bath. "B12 Chemtool" is a clear colorless solvent when new, but not after cleaning the injectors. To be fair, some of that was gunk from the outside of the injectors.

After cleaning in the ultrasonic, I used a contraption and a catch can to run B12 Chemtool through each injector. I connected about sixteen inches of rubber supply hose to each injector and filled that hose with injector cleaner. I manually applied maybe 10psi of air pressure to the supply hose and, using a small 12V battery (like from a motorcycle, uninterruptible power supply, or a portable jump start unit), I simultaneously pulsed each injector, also manually, until all the injector cleaner passed through, catching the cleaner in a jar. After I did that a couple times, I backflushed each injector by connecting the "supply" hose to the injector output and repeating the procedure with the injector upside down. I might have forward flushed each injector again after that with fresh injector cleaner.

I replaced the nasty, likely original, o-rings and plastic bits with a "Bosch EV1" injector rebuild kit I got on eBay for around $16USD. I don't know exactly what "EV1" means in this context - it has nothing to do with the General Motors early electric car model of the same name. The EV1-style of Bosch injector was widely used on all kinds of vehicles in the 80's and 90's.

The kit I got was for an America V8, like a Mustang, which is why you see eight sets of new parts pictured below. I figured having some spares around won't hurt. Make certain you get a kit that includes the little filter screens that sit inside the fuel supply opening of each injector.

The old screens can be removed by inserting a #10 screw a turn or two into the old screen and pulling with a pliers.

Old Crusty Injector Parts

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Bosch "EV1"-Style Injector Kit

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New Mesh Filter Installed

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[stitch2k1]

Link to where to get those rebuild kits? I should've looked into that before I overpaid for the three sets I've done in the past.

[usury]

Link to where to get those rebuild kits? I should've looked into that before I overpaid for the three sets I've done in the past.

Sure thing! This is the exact listing I purchased...

https://www.ebay.com/itm/203832719166

For people finding this post in the future, this eBay search should help...

https://www.ebay.com/sch/i.html?_dmd=1& ... uild%20kit

[DMRK]

Thanks usury, nice tip!
I have found that a 9V battery works great to open the injectors.

[Lowencash]

Fantastic, thanks for sharing!

For what it's worth, I used this inexpensive device to clean the injector and check the spray pattern.

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[usury]

For what it's worth, I used this inexpensive device to clean the injector and check the spray pattern.

That cleaning device looks much easier than the air compressor/rubber hose/jumper wire contraption that I used. Great tip!

[dr bob]

Great stuff!!

For the injectors, the suggestion about using the 9V battery is spot-on, especially if you plan to leave the injector energized continuously for cleaning. The 9V battery is plenty to open the injector, and is actually closer to normal actuation voltage that the injector sees in service.

My final clean and spray-test "rig" is the fuel rail itself, off the car with injectors installed. It's easy enough to fill the rail with cleaner and pressurize it with air, then actuate the injector under test.

I buy that Berryman's B12 by the case at the local WalMart. By far the lowest-cost source I've found. It gets added to the fuel tank regularly, works great for on-the-car cleanings with my injector system cleaning cannister setup, plus great in the ultrasonic as you show. I do put the injectors in a small ziplock bag, no air, and seal it before dropping them into the ultrasonic. Keeps the flammable-fumes danger down while cleaning in the ultrasonic for sure. Most ultrasonic cleaners are not intrinsically safe. Use them safely outdoors if you have flammables, not in the wood garage that's attached to your wood house.

More On the flammability part -- Be sure to do your spray testing outdoors safely away from structures and anything that might suffer if you have a fire. Your nice clean injectors are spraying a perfectly-atomized flammable fog. Spark comes from the electrical connection especially with battery clamps as you disconnect. Whoosh! Keep that fire extinguisher or a charged garden hose handy. Don't Inhale Flames -- it's always fatal, and not a great way to exit this life.