- posted
10 years ago
fuel injector cleaning question
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- posted
10 years ago
I can't speak to in-port fuel injectors, but I've run a throttle body injec tion unit (2 injectors spraying into a carburetor-like body) for 358K miles without ever once cleaning it until last week. It seems to run fine. Whe n I disassembled it I found nothing in terms of buildup on it, which contra sts sharply with some opinions on the internet. ("You'll be amazed at how much crud you'll find.") I can't explain this; fuel quality? I buy the ch eapest fuel I can. There's no way I know of to quantify exactly how good y our spray patterns are, though people have installed removed injectors in a benchtop manifold and taken flash photos of the spray pattern, which will show obviosuly bad patterns, caused by partially clogged nozzles. In the a bsence of such an exercise, it seems like guesswork to me if fuel injector cleaning is needed. A chemist friend used to tell me, "without data, you'r e just another person with an opinion".
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- posted
10 years ago
I pulled the injectors out my old Pontiac at 150k miles to replace leaking O-rings. The injectors had a slight discoloring to them but otherwise were clean.
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- posted
10 years ago
Somewhere, I a tech bulletin issued by Ford in the early 1990s that says they switched to clog-resistant injectors around then and that cleaning isn't necessary. I don't remember if it says cleaning isn't recommended. Also in the mid-late 1990s, gasoline got better (more or better detergent additives) because of EPA requirements and demands from auto makers, making injector cleaning even less necessary.
If you want to use an additive, get a bottle of Chevron Techron, but don't use it too often.
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- posted
10 years ago
"Clog Resistant" belongs in the same BS bin as "Affordable Health Care"
What it amounts to is a different screen and tip design. They still develop problems. The thing is that most chemical cleanings only work if the deposits in the injectors are something that the chemicals can dissolve. Rust, dirt, solid particles won't come out. For those it's rebuild or replace time.
The alcohol in the fuel these days frees up a lot of crap, but usually you won't notice because the filter catches a lot of it, then the screens catch some. They can flow more fuel than the injectors so until a major blockage happens things don't change much.
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- posted
10 years ago
Two problems:
- Gunk building up at the tip. Used to be a problem, isn't anymore.
- Gunk building up in the screens. Never used to be a problem, is now.
On the older Bosch injectors for the BMWs, pulling them apart and cleaning the screens isn't that big a deal.
Some of the fuel system cleaners are solvents that dissolve gunk, some of them are detergents that help them unstick. For the most part the solvent kinds don't do much good if they are mixed with gasoline rather than run directly into the injectors.
--scott