Fluid to use in Injection Tester

@Thewespaul @typ4 @Agnem or anyone else with experience

I used to have an easy way to get filtered Diesel to put in my pop tester but I haven't had that setup in a while. The pump shop I used to use always told me that they only used something called a calibrating oil but I can't find it available to the public. Is there a "canned" alternative available similar to buying a gallon of Kerosene or pre-canned 2 cycle fuel from a hardware store that would likely be filtered from the factory better than my local gas station? Would kerosene give inaccurate numbers? Would they be higher or lower than #2 enough to make a difference? Mostly I'm just trying to make sure they are a close match and not push crap into my injectors but if I know a little more I can educate my guess a little better, thanks for any ideas.

The reason you aren’t going to find a public option is quantity. You can really only buy calibration fluid in 50 gallon drums for a small fortune. The reason fuel shops are only running calibration fluid is it’s non flammable, and it’s a manufacture provided fluid that is exactly the same in viscosity as the current fuel. You should be able to go into a fuel shop with a 12 pack and some cash and they will fill up a clean 1 gallon container for you. If you can’t find anyone, you can just run atf and it will be pretty close.

Thanks Wes.....so the viscosity of the fluid won't affect opening pressure of the spring, I was thinking that already but wanted to verify? Will ATF still show me an accurate representation of the spray pattern? I guess since I'm just comparing against the others and looking for dribbles it should be ok? How long do you leave the injector pressured up to check for leaks at the pintle? Just a few seconds and watch the tip or so or leave it for a minute and watch the gauge pressure? I do clearly remember the warnings to keep injector spray away from my skin and avoid breathing the fog but if you have a chance to offer any quick tips I'd appreciate it.

IIRC, at the shop I used to work at, we used a 50/50 mix of ATF and diesel. I didn't use it very often and I left in 2001 so some of the little details are fuzzy.

I'm not going to say that it was perfectly representative of diesel, but I like to use ATF in mine. Seems to give me more... consistant readings.
And honestly, it doesn't matter if everything ends up 1% off - what matters is /relative/ pressures (and spray pattern to some minor extent...) and leakage.

ATF will be close enough for your purposes, honestly the calibration fluid wont even be 100% representative of how it will fire with an IP behind it that isnt a simple sine wave pump and is super heating the fluid. Just check for dribble under pressure and sitting after firing, you only want to engage the gauge when testing opening pressure, shut it off for testing leakage.

Thanks for the tips guys, that's what I was looking for and will get me where I need to be for this one.

Calibration fluid is also stable if the parts are stored for an extended time. I do have a source that will sell and ship 1 gallon containers of calibration fluid.

I test with the fuel that the truck will be running.
What Macrobb and Thewespaul said, but testing with the actual fuel will tell you exactly how the injectors will behave.

Hey, Macrobb. It's been a while since I've seen you on here. I was starting to wonder if something happened to you. I don't know about the calibration fluid, but using ATF should help clean out he injectors some too.

IDIBRONCO said:

Hey, Macrobb. It's been a while since I've seen you on here. I was starting to wonder if something happened to you.

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Yeah, I've just been really busy lately. Haven't done much of any work on my vehicles after the last batch with my '00 PSD... Both it and my red '93 are running DD's and keep on going, so... I haven't done much.

IDIBRONCO said:

I don't know about the calibration fluid, but using ATF should help clean out he injectors some too.

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Yup, this is definitely a plus. Also it doesn't evaporate.

Looks like amazon sells calibration fluid in one gallon containers
https://www.amazon.com/OTC-OTC20862...s=otc+calibration+fluid&qid=1578644262&sr=8-1

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Philip1 said:

Looks like amazon sells calibration fluid in one gallon containers
https://www.amazon.com/OTC-OTC20862...s=otc+calibration+fluid&qid=1578644262&sr=8-1

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Ouch. If any one really wants some PM me, My source is a 1/3 of that or at least it was 4-5 years ago.

Nope, not buying it... $60...
I'll just use atf when I ever get one of those round to its and make pop tester...

Philip1 said:

Looks like amazon sells calibration fluid in one gallon containers

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Thanks for at identifying a part number for me. That is pretty pricey but with a part number I'll use my google fu and see if there's a better deal to be had for future reference.

FWIW I tested the two sets of injectors we were debating putting in the motor we're assembling. One set of original 300k+ "G" and a pretty low mile set of "E"s. My dad brought a gallon of PS fluid with him instead of trans fluid (thought it was trans b/c it was in a big white valvoline bottle) so we used it instead. I don't think I'll be doing that again b/c I'm not happy with the way the test went, we should have quit and gotten ATF or tried to filter some #2. I expected that the pop/chatter that I remember would be have been dampened with the heavier oil but I think my results were still pretty disappointing.

For most of the "G" injectors I was able to a distinctive opening and closing event albeit very soft and weak and usually a little chatter as I elevated above the opening pressure but most were still pretty low with a weak spray and squirted more than I expected. Only one seemed to just dribble continuously above 1000psi.

"G" Code
#1 1500
#2 Dribble
#3 1450
#4 1550
#5 1475
#6 1375
#7 1425
#8 1600

For the "E"s, I was hoping they would be clearly better but they just seemed odd to me. I couldn't get any to chatter or give a distinct crack as they opened, it was just the needle peaked and dropped a bit with a disappointing squirt or dribble. Pressures were definitely higher but behavior was strange to me and all of them seemed to leave a much larger drip on the tip after it closed than the "G"s. If I tried to just force some oil through it, it gave me a squirt for sure, not anything resembling a spray.

"E" Code
#1 Dribble but weirdly high starting @ 1700 like it had trouble closing
#2 1575
#3 Dribble
#4 1650
#5 1650
#6 1550
#7 1550
#8 1650

Then I ran across a post from Wes comparing the spray patterns of some super secret injectors he's hording to "E"s. He says "Overall, these injectors don't ever real get to the "water hose" level, even at 150 psi they have a spray pattern of sorts, unlike say an E code that goes straight into injector ******* at 1500 psi"

So what's with the "E"s? I thought they were the "emission" injectors and was kind of expecting the best atomization from them. Are the ones I tested maybe behaving as expected except for the couple odd ones? What should the "E"s open at? I remembered 1800 being the target and was expecting something lower but as I said before this was strange.