Thoughts on Injector Cleaner?

Post by **hausmeister** » 09 Dec 2025, 14:02

Not sure how much cleaners do. PEA is mostly used/recommended for direct injection.
Probably good as a precaution, but not sure if it can fix a real problem.

I disagree on dirty or gummed up injectors causing a code... as long as they put in enough fuel and it ignites it wont. You can take out injectors and test /clean them. Spray pattern could be really bad, amount might be incorrect. In my opinion it is best to get some refurbed or new injectors for cars that old (or at least clean and test them). The ones in my 850 were really bad. Car still ran though, no way to tell.
I wouldn't expect any cleaner to fully clean 30 year old injectors that are in the car... for prevention, sure, why not. Once a year or something.

Post by **matthew1** » 11 Dec 2025, 17:01

Grocery store yesterday, made me think of this thread:

: IMG_1620.jpeg (365.15 KiB) Viewed 499 times

Cees Klumper · Post by **Cees Klumper** » 04 Jan 2026, 12:57

About 10 years ago I tested out the usefulness, or lack thereof, of injector cleaners. Bought a generic brand cleaner in our French grocery store and tried it out on both our first gen high-mileage S80 and C70. To my surprise, both cars' fuel economy materially improved - and wasn't bad to begin with. As in, about 5-7% improved, long-term. Since then I am converted and run a bottle (usually Techron) through all my cars and motorcycles once a year.

Post by **abscate** » 06 Jan 2026, 01:52

hausmeister wrote: 09 Dec 2025, 14:02 Not sure how much cleaners do. PEA is mostly used/recommended for direct injection.
Probably good as a precaution, but not sure if it can fix a real problem.

I disagree on dirty or gummed up injectors causing a code... as long as they put in enough fuel and it ignites it wont. You can take out injectors and test /clean them. Spray pattern could be really bad, amount might be incorrect. In my opinion it is best to get some refurbed or new injectors for cars that old (or at least clean and test them). The ones in my 850 were really bad. Car still ran though, no way to tell.
I wouldn't expect any cleaner to fully clean 30 year old injectors that are in the car... for prevention, sure, why not. Once a year or something.

The fuel management systems on these cars are closed loop on total oxygen in the exhaust, so if one injector is weak that cylinder will run lean and extra gas will be put into the others. You only get about 10%adjustment before a code, though

Post by **hausmeister** » 06 Jan 2026, 02:17

Ok, makes sense. Depends on how bad they are then

Post by **volvolugnut** » 06 Jan 2026, 07:41

I had read years ago that Techron was the best cleaner. If I use any cleaner, Techron is the one.
volvolugnut

magna224 · Post by **magna224** » 30 Jul 2026, 15:55

volvolugnut wrote: 06 Jan 2026, 07:41 I had read years ago that Techron was the best cleaner. If I use any cleaner, Techron is the one.
volvolugnut

When I got my car it had a lot of thick carbon around the valves and after running a bottle of techron (because I heard it was good for this) it disappeared. Maybe it would have just done it naturally over time anyways with a decent gas but it was surprising to see it go from visibly very bad to shiny and new looking. After that I just ran chevrons gas since it has it in and every time ive taken the manifold off its been spotless. I replaced the injector baskets and ran seafoam through them and replaced the fuel filter. The injectors had some stuff in the baskets after running the techron. Im not sure if the 'dirt' was caught in the basket before I ran the techron though. Ive never ran seafoam through the car though its always seemed sketchy to me and i never tried any other additives.

Post by **scot850** » 30 Jul 2026, 17:29

I have had lumpy starts in my 03 V8 4Runner for a couple of years. It was put down to various expensive issues by Toyota and Toyota 'specialists', all who had good recommendations.

It recently got to the point where on start up you could smell the unburnt gas in the garage, and it sounded like a light knock for the first minute of running and then the engine seemed to settle down. I don't do a lot of highway driving, but recently needed to a longish run. I topped the tank up and added a fuel system/injector cleaner. I had little faith, but I thought the issue was a leaking injector causing these issues.

Well the day after the trip, I went out and started the car. Not only was the start a lot faster, but ZERO light knocking and no strong smell of gas in the garage.

Since then I have thought about doing a 2nd round if I do another longer run.

Some of the reason for the injector issue I put down to my short trips and the excessively long time the Toyota takes to warm up. Ok, a bigger engine (4.7l V8), than our Volvos nut it takes more than double the distance to get up to temp, especially in the winter even though it is parked in a heat garage. It has also recently had a brand new OE thermostat and coolant flush and new OE coolant.

The car gets synthetic oil and oil filter change every 6000km (for my that is yearly) and is run on Premium (91) gas.

So I thought using injector/fuel system cleaner was a long shot, but for my case it seemed to have worked really well.

Neil.