DIY Fuel Injector Cleaning and Test Bench (Arduino Nano)

[MaritimeBay]

Hi all,

Just sharing a recent project I've been working on. I'd been daydreaming about this for about a year now since I bought a load of fuel injection parts that came with around 16 bus fuel injectors. Knowing that sending all of these injectors away to a company in the States to have them cleaned would break the bank, I set about to learn how to create a test bench and cleaning system that I could use at home. After much research on the internet, I settled on using an Arduino-type microcontroller along with a MOSFET module to pulse the injectors in way similar to a fuel injected vehicle. Using the code found on this website (with some modification)http://www.sergentbrico.com/fabriquer-testeur-injecteur-arduino.html., I was able to rig up the electronics part of the project relatively easily.

My general process was:
1. Test injector spray pattern and volume outputs on the test bench (to get a baseline), and check for leaks.
2. Clean the injectors in ultrasonic bath while running the same cycling as the testing except a longer delay before the program starts a new loop.
3. Replace pintle cap, filter, rubbers on all injectors.
4. Test injector spray pattern and volume outputs on the test bench.

If there's interest, I can post a more detailed list of parts used, code for the arduino, and general cleaning/testing process or answer any other questions.

This is probably not close to the level of cleaning you would get from some of the pro shops mentioned on these forums, but as a Canadian (and stubborn individualist), I just couldn't justify sending my injectors away given the shipping and exchange rates. That being said, after cleaning one set of injectors this way, I've noticed a huge improvement in the spray patterns and volume output. The amount of fluid put out of the four injectors after a few test cylces is much more uniform after cleaning than it was before, and that's really what I was after.

The rig in all it's glory:

Injectors in the ultrasonic bath:

Power from car battery goes through resistor pack before heading to injectors:

Arduino Nano:

MOSFET Module that routes 12v battery power to resistor pack:

Used a #8 screw in a vise to pull injector filters out:

New injector parts:

Finished babies (no new paint this time around):

More where that came from:

_________________
1977 2.0L FI Westfalia.

They call my home the land of snow.

[telford dorr]

[Wasted youth]

[oscarsnapkin]

Man, you need to enter that setup into a school science fair. Very cool. I made a hydraulic brake setup mounted to plywood for a high school physics class, yours is much cooler and a lot more sciencey.
_________________
- 1977 CEI Sunroof Bus 2.0L F.I. Hydraulic Lifters
- 1973 Thing

"It’s so easy to laugh, it’s so easy to hate, it takes strength to be gentle and kind."

[furgo]

This is fantastic, good work and thanks for sharing!

[Wasted youth]

[telford dorr]

The point is IF the injector is energized, THEN it needs some fuel flow to cool the drive coil. All that energy has to go somewhere. The ultrasonic won't contribute any heat (although some models have a heater to heat the cleaning fluid, but you wouldn't use this feature with hydrocarbon type cleaning fluid, for obvious reasons). Ultrasonic cleaners can be found on ebay used. They also work wonderfully for cleaning carbs, and other small parts. Pulsing the injector while being cleaned would allow deposits on the pintle and its seat to be removed, but I would prefer fuel also be passed through the injector to force these loosened debris to be flushed out of the injector, and to keep dirty cleaning fluid from working its way into the injector. Now this fuel will increase the volume of fluid in the ultrasonic cleaner, so it would have to be periodically removed and discarded. You would only have to run low pressure to the injector, so the amount of fluid growth could be controlled.
_________________
'71 panel, now with FI
'Experience' is the ability to recognize a mistake when you're making it again - Franklin P. Jones
In theory, theory works in practice; in practice, it doesn't - William T. Harbaugh
When you're dead, you don't know you're dead. The pain is only felt by others.
Same thing happens when you're stupid. - Philippe Geluck
More VW electrical at http://telforddorr.com/ (available 9am to 9pm PST)

[BayCreamPuff]

This is awesome! I've got a few piles of FI parts and injectors and have been wanting to build something like this for a while. I also have an Arduino Uno and a starter kit that should have everything I need.

Please share the code if you would. I'm a software engineer and would be happy to help extend it in any way (make it send you a text message when it's done? Call the fire department if it catches on fire?)
_________________
Cream Puff
'79 CA Stock FI Deluxe Campmobile

Earl Grey
'87 GoWesty 2.2 Westfalia

Marsha Mellow
'00 Eurovan VR6 Full Camper

[telford dorr]

[furgo]

[MaritimeBay]

Hi Guys! Thanks for all the feedback. Below is the code I ended up settling on. Note the comments after the '//'. There was really only one modification to the original code.

Essentially what it does is pulse the injectors at increasing widths up to 70% of 29ms. The increase after every ten cycles is 0.05ms. Once it gets to a 70% duty cycle, the program stops.

This does not mimic our FI systems perfectly, because it really only replicates a 0-70% duty cycle at around 4100 RPM. If I were to make this a bit more 'realistic', I would be testing 3%-85% duty cycles at total cycle widths that match 850-4000 RPMs. Close enough for now.

Future iterations will include actual button options (test/clean/manual) and an LCD display.

[MaritimeBay]

[furgo]

Thanks for the answers!

[MaritimeBay]

[quote="telford dorr"]

[telford dorr]

Thanks much for the link. Now have two on order.

For orders shipped to the USA, use this URL: https://www.amazon.com/Gikfun-Expansion-Terminal-A...al+Adapter. The Canadian one won't ship to the US. Otherwise, it's the same vendor.

Side question: what did you use for the 5 volt supply for the Nano? Didn't see anything definitive in the pics OK, it's running off the computer USB connection - DUH! Disregard...
_________________
'71 panel, now with FI
'Experience' is the ability to recognize a mistake when you're making it again - Franklin P. Jones
In theory, theory works in practice; in practice, it doesn't - William T. Harbaugh
When you're dead, you don't know you're dead. The pain is only felt by others.
Same thing happens when you're stupid. - Philippe Geluck
More VW electrical at http://telforddorr.com/ (available 9am to 9pm PST)

[IgnasKl]

I really liked your project, but what size resistors you used ? I'm talkinkg about Resistor pack. What size is the resitors, and how did you conected them ?
Thank you for your answer!

[SGKent]

[telford dorr]

Otherwise, 5 ohm 10 watt.
_________________
'71 panel, now with FI
'Experience' is the ability to recognize a mistake when you're making it again - Franklin P. Jones
In theory, theory works in practice; in practice, it doesn't - William T. Harbaugh
When you're dead, you don't know you're dead. The pain is only felt by others.
Same thing happens when you're stupid. - Philippe Geluck
More VW electrical at http://telforddorr.com/ (available 9am to 9pm PST)

[MaritimeBay]