Fuel injector cleaner in the tank: the case of the missing photos

My son gave us a membership as a present to Sam's Club a while back so that we could partake of their cheap gas. Which we did for a year. Then I discovered much to my chagrin that unlike all the major gas stations and Costco it wasn't top tier gas. Oops. So, remembering back to the bad old days when gas wasn't full of detergent and injectors would often work poorly, it seemed like a good idea to put some injector cleaner through. Poured a bottle of Techron in and hoped for the best. (Both cars were running OK, if they were gummed up, it wasn't too bad.)

Then when I thought about it, I realized that in all the "injector cleaner in the gas tank" videos, web pages, advertisements, and blog posts I have come across, there was one thing I had never, ever seen. That is: before and after pictures of the spray pattern for an injector which has been treated with a bottle of injector cleaner in the tank. Also missing: measures of the flow rate before and after. There are lots of pictures of the tops of pistons, which is all well and good if one cares about a little carbon on top, but doesn't really say anything useful about what happens inside a gummed up plastic injector at vastly lower temperatures and much higher solvent concentrations. There were before and after pictures from injector cleaning services, but their cleaning conditions are usually very different, like running normal gasoline through an injector while it turns on and off tens of thousands of times in an ultrasonic bath.

These products have a reputation for being snake oil, so if I was a manufacturer trying to sell this product, I would be sure to present this information to the consumer. But they don't. Perhaps because it really is snake oil, or at least, is only useful for keeping the injectors clean but will not clean a dirty one?

Anyway, if anybody has a link to the missing photos cited above, please post it!

 

I think you may be referring to the picture shown about 1/4 of the way down here:

Techron® Concentrate Plus | Caltex Hong Kong

Notice the asterisk: "results may vary"? There is no information provided to support the idea that picture is representative. For all we know that picture is a 1 in 1000 result, with 999/1000 having no significant improvement.

Again, I'm not saying that Techron in gas at the pump isn't very good at keeping the fuel system clean. But that's a much easier task than removing crud that is already firmly attached.

 

Back on topic, here is a video about Techron from Chevron. Notice anything missing?

Now that I'm looking for it, the ads for this entire class of products are remarkably data free.

There are also "on car" injector cleaners. These plug into the fuel rail and run their cleaner (often a 50/50 mixture of some cleaner and gasoline) straight into the engine. The gasoline engine runs until the cleaner mixture runs out. So far I have not found before/after measurements of fuel injectors for this type of cleaning either. This method is more likely to get the injector clean than an in tank cleaner, since the cleaner is much more concentrated as it passes through, but that may also be more likely to damage the injectors for the same reason.

The injector cleaning shops are the only ones which reliably provide before/after numbers and/or pictures.

So, I thought about how one would set up a reliable test for comparing in tank fuel injector cleaners, and it becomes evident in short order that the hardest part would be making a "standard" dirty injector so that all cleaners face the same challenge. Looking at the injector cleaning shop reports they often find a wide range of performance for the injectors from a single car, which have been exposed to as close to "the same" conditioning as one could reasonably manage. One can imagine some "gunking chamber" which runs a standard low quality gas (no detergents) through a large set of injectors, and temperature cycles them to approximate what happens in a car. Probably for 24 hours a day for months. However, if the in car results are any guide, the likely outcome would be unacceptably nonuniform "dirty injectors". To work around that one could test the "before" performance of each injector, assemble closely matched sets, install them in identical cars, run the cleaners, then pull the injectors and test again. Sounds like a time intensive and very expensive experiment. Chevron could afford it, but they don't have much incentive to do this, since they sell tons of Techron on nothing more than "trust us"! Also they would likely find that the product failed at an embarrassingly high rate, which they would rather not document, and they certainly wouldn't want to advertise it.

A cheaper test might be possible on cars with individual cylinder fuel control if that data can be read from the OBD2 port. Find cars with a wide variation in the per cylinder values (with brand new plugs to eliminate that variable), and then run cleaner through them. If it works they should even out, if not, then they won't. Mechanical defects at the cylinder or in the injector would greatly complicate the analysis.

 

This is still anecdotal, but if the guy is remembering the details accurately, it contains a description of some reasonable tests:

https://hummer4x4offroad.com/forum/threads/injector-cleaner.6639/#post-115588

Just in case that site ever disappears, I am going to quote the whole post here:

 

This gets more and more bizarre. Recall how Top Tier gas is supposed to limit deposits on valves, cylinders, and in the fuel injectors? Turns out that the testing requirement for fuel injectors was removed in 2015. That test used to be part 4.3.1.3 of the standard, but it no longer is:

https://www.toptiergas.com/wp-content/uploads/2022/10/TOP_TIER_Detergent_Gasoline_Performance_Standard_revF_2019-12.pdf

I have not been able to locate an earlier revision that contains the old fuel injector test requirement. Which is too bad, as it would have been nice to know how that test was performed.