Ultrasonic fuel injectors cleaning

[mhmmdqureshi]

Dear members,

I've a Honda City vario 03, it's giving bad avg and vibrations with ac in drive mode. I have cleaned its throttle changed plugs, scanned the car there is no electronic issue.

I'm using zic 10w40 fully synthetic, I change it every 3500kms. I've read about fuel injector cleaning using ANSU machine.

I want to know where I can find it in rwp/isb. How effective it is? Should I go for it or not?

Thank you.

[zakiuddin]

giving bad avg and vibrations with ac in drive mode. I have cleaned its throttle changed plugs, scanned the car there is no electronic issue.

I'm using zic 10w40 fully synthetic, I change it every 3500

Before you take out fuel injectors for cleaning, make sure that you've narrowed down on injectors.
There are two types of Fuel Injector issues that i've came across: a. Chocked Injectors, b. Leaking Injectors.
a. Chocked Fuel Injector can be identified by -ive fuel trims, sometimes accompanied by misfires
b. Leaking Fuel Injector exhibit symptoms like +ive fuel trims and rough/uneven PreCAT O2 sensor graph on idle; unlike a sinusoidal waveform which we are all accustomed to..

The last time i cleaned the injectors, i used this simple adaptor + Carb cleaner:
https://www.ebay.com/itm/Car-Vehicle-Fuel-Injector-Flush-Cleaner-Adapter-Cleaning-Tool-Nozzle-DIY-Kit/254699929409?hash=item3b4d4c7f41:g:hZsAAOSwVzpdpR77

You can also find solutions like fuel injector cleaning fuel additives which are easily available on daraz.

[mhmmdqureshi]

Thanks for the reply, as I've cleaned throttle, changed plugs and have every necessary maintenance done, but the problem is as it is, so now I think fuel injectors might be the cause because my car have 157k kms on it and not a single time injectors are cleaned. But car don't misfire and the other thing waveform and o2 sensor graph, I don't get it. Can you please explain it?

[zakiuddin]

The first thing you need to do is to hook up a scanner and look at your LTFT (Long Term Fuel Trim) and STFT (Short Term Fuel Trim). Ideally, your LTFT should be around zero (0) and STFT varying by +/-3 but still around 0 (zero). Practically, your LTFT+STFT should be less than -10%. Then you need to look at PreCAT O2 sensor and plot a graph of voltage it's generating.. You should get a sinusoidal waveform. With leaky injectors, instead of a smooth waveform, you get a cluttered and uneven waveform.

[mhmmdqureshi]

What type of scanner is good? Can you recommend me one.

[zakiuddin]

The cheapest one that i've used is a Bluetooth ELM327 Diagnostic Scanner with a mobile app "Car Scanner", you can get the ELM327 from any online shopping site. Even daraz.pk lists quite a few.