[Snow King]

There are plenty of threads on this forum accurately stating that fuel system cleaners cannot clean the intake values on direct injection engines. Reading this over and over again, I falsely assumed it wouldn't make any difference in my car and would be just a waste of money.

Meanwhile, I've been having rough idling at cold or hot temps for several months. At speed or WOT, no issues, car runs smooth. But at idle it was so noticeable that some passengers noted "how shaky" it was sitting at a stop light.

I know, I know, I should have my intake values cleaned but I gave the techron concentrate fuel system cleaner a try after reading a recent thread with positive results. And like no joke half way through the gas tank all of my rough idling issues are now completely gone. I tried listening for any hesitation at stop lights during my commute to work and back. Many minutes listening and smooth as butter at idle now!

Must have been the original injectors that were plugged or rusted up inhibiting flow, cleaned that sucker right out. For those of you with rough idle or performance give it a try. Especially if you are running shitty ACN91 fuel, I'm no gearhead but I have a feeling that may have contributed to the idle issues.

[Titanium3er]

Placebo

[blacknbean]

it does clean the injectors and maybe the fuel lines, but thats about it. i still use it though.

[Gizm0]

Intake values?

[Surly73]

Snow King: You have a perfect understanding of what's going on, and a fuel treatment may help your issues but, as you point out, it isn't because of valves. Any kind of "instant" effect is probably not due to its cleaning. Cleaning isn't instant. An additive can change the way fuel burns etc.... Lots of people have said their cars run better with a maintenance dose (i.e. every tank) of Redline SI-1 in their fuel...

For what it's worth, Techron is one of the "good" cleaners out there that isn't just some cheap solvent with dye in it. However, the use of Techron has been frequently associated with increased lead wear metal in used oil analysis. I've seen it with my own eyes on my dad's E39. He burned Techron premium fuel during a two month stay in FL and his oil had a lead spike. (This is on top of lots of "Internet" evidence).

The direction I've seen is that cleaners with PEA are best of breed. These include Amsoil PI2, Redline SI-1, Gumout products with REGANE on the label (the non-REGANE ones don't have PEA). Redline SI-1 is my favourite but Regane is far easier to get in my area.

I started using an every-tank treatment in my E39 w/ M52 which completely removed all combustion chamber carbon (from what I could tell through the plug hole). There were two to choose from - Lucas UCL (upper cylinder lubricant) and LCD Inc. FP60 and FP+. My E39 lost noticeable power at lighter throttle angles (i.e. most in town daily driving) running Lucas. I noticed no ill effects from LCD so I kept running it. I still have a stockpile so I started using it in my E90 when I got it. I think the LCD FP+ treat rate is 1/2 oz. per 10 gallons - I put it in at every fill up. Maybe some DI operators should try something like Lucas UCL or FP+

http://www.lcdinc.com/products_fuel_power.php

[Meeni]

Cleaned your injectors and maybe deposits inside the chamber as well. Cleaning injectors is very effective on its own, even on engines that have no valve deposit issues.