[cj847]

Not sure where to post this. Moderators please move if needed.
One thing I have been reluctant to try is having fuel injectors cleaned. I finally tried it the other day and wanted to post the why and the results.
First, I think in general fuel injectors don’t need to be cleaned. Gasoline at the pump has enough detergents to keep them in good shape. The first pic is a shot of one of my LS swaps. The LTFT and STFT are near zero, indicating no problem.
On my other LS swap, I had very high long term fuel trims. They were +25 which is when the CEL is supposed to come on. Along with that, the short term fuel trims were +15 to 20.
There are multiple things that can cause fuel trim to be out. First, I checked for vacuum leaks and found none. Then, I checked the MAP readings they were OK. The MAF was giving believable readings as well. Fortunately, I have another LS swap, so I pulled the MAF from it. It showed immediate drop in LTFT into the low 20’s. So, I replaced the MAF. Still, LTFT should be <10 generally. I decided the only thing left was clogged injectors.
I pulled the injectors and sent them to Advanced Injector. Turnaround time was just a few days. The injectors came back with a full before and after report. As you can see, even though my junk yard LS probably has close to 300k miles on it, the original injectors only varied about 5% from original specs.
After re-assembly, the LTFT’s have been slowly dropping. It takes a while for it to update. As you can see from my live data, LTFT are down to around 8 and the short terms are still mostly negative. So, I’m calling it a successful venture.
In conclusion, I think that your fuel injectors probably don’t need to be cleaned unless you have some issue that points to a leaking or clogged injector. Or, you are building a high HP motor and need the injectors to be balanced.