This is a great idea since the majority of the time, all you need is a backflush.

 

After using eGuard for more than a year, I finally have enough run time with it to make some useful observations. I have been running eGuard at twice the recommended concentration to make sure that I'm giving it a chance to do something useful. (Champion tech support told me that there was no issue with running higher concentrations.) First thing I'll say is that in general, gunk buildup seems to be more prevalent in the warm summer months. All last winter and spring were totally fine.

However, in the latter half of this summer after some especially hot days, I started getting cold engine misfires, and my fuel trims started going positive. In watching engine behavior and fuel trims, what appears to be happening is that the injectors are gunking up in around-town driving, but when I get on the highway for more than about 20 minutes of steady driving, they clear up, and fuel trims go back to normal. This is consistent with the SAE article. An important contrast is that when I was not running eGuard, once my injectors gunked up, they would not clear up under any conditions.

So it appears that at twice the recommended concentration, eGuard has some benefit. I may try 4x the recommended concentration to see if the injectors stay clear in around-town driving.

 

Is eGuard financial responsible, or is it easier for most of us to just the occasional tank of pump gas?

 

Im on the 91 flush as we speak.

Just filled this evening w/a full tank. Will run a min of 2 tank fulls

 

I run pump gas unless headed to the track, anyway. But, if eGuard is reasonably priced and works, then dealing with the hassle of planning mileage, to swap fuels, would be one less thing to worry about. I'd consider it.

 

At 1 oz/10 gal of E85 (double the suggested concentration), it costs only 10 cents per gallon to use it, so the cost is quite reasonable.

The problem I have with running an occasional tank of pump gas is that I've seen my injectors gunk up very quickly, almost within one tank of E85. It really seems like hot weather can cause strong issues. So running an occasional tank of pump gas doesn't necessarily lead to injectors that are always clean. My goal for using an additive in E85 is to always have clean injectors.

Another option I may try is always filling with 10 gallons of E85 and 2 gallons of name brand premium fuel such as Chevron. This would produce E70 for the E85 in my area. Perhaps the additive package in the name brand gasoline may be good enough to keep the injectors clean.

Either approach has some amount of hassle associated with it.

 

If my injectors were gunking up after one tank.. then yeah. I could see running pump gas as not working so well.
I think I'd have to just stop running e85 at that point. It's fun, but not that fun LOL

 

I pulled out my ID1000cc injectors last month after building my engine. 19,000 miles on them. 95% E85 (E76-79)

They looked good as new, zero gunk or build up. I'll take some photos if nobody believes me.

 

7 years, 80kish miles, not a single tank of gasoline. California sucks in a lot of ways, but E85 quality is not one of them.

 

Not surprised, after reading the report posted in the other pages. You never know until you run it and check.

From what I can tell, my local supply is okay. I don't think anyone in my town has had a problem. A guy that lives in the next town, however, wasn't so lucky. The weird thing is, I always assumed he bought his e85 here. My injectors have always been clean. I tend to alternate 2 tanks of e85, then one 91oct, just in case.

 

I can totally believe it. Mine were super clean on straight E85 when I was living in the Tricities that has a different source of E85.

 

I live in Fort Wayne, Indiana And have been running E85 from local lassus station all year without any tanks of 93. In the winter when it gets to freezing temps, I do switch to 93 for the winter.

Is it better just to stay on the e85 all year till the winter hits and then switch over to 93?
or should I really be throwing in some tanks of 93 throughout the year?

*car is on walbro 255 with ID1000s and been running e85 for 30K+ miles now. I do clean the injectors in the fall before going to 93 in the winter.

 

Totally depends on your local supply and storage. To be safe, I run pump every tank, or two. My area hasn't had problems, from what I know..But not taking any chances.

 

I didn't read all the posts, but I will say that I talked with Injector Dynamics and they believe that the gunk is from RUBBER HOSE being SOMEWHERE in the fuel system. It could be IN TANK or the FUEL RETURN or the FEED or whatever. In time the E85 erodes away the rubber and it collects at the injector somehow. I don't run E85, so that is all I have to add to the thread.

 

The most accurate answer we have received IMHO is this pasted here: (Its starts on page 9)
The deposits primarily consist of "Poly Iso Butylene," or PIB, a cleaning additive in the gasoline portion of commercial E85 blends. As far as we know, the ethanol itself doesn't directly cause this type of problem with injector and valve deposits. This PIB additive was never designed for use in high ethanol concentrations.

PIB is designed to soften engine deposits, but below a certain concentration (by total fuel volume) it is actually counter-productive. What happens is that with insufficient PIB by volume, the normal valve deposits don't soften. The PIB actually combines with these normally occurring deposits and makes build up worse.

Running PIB-free E85 is basically impossible in a practical sense. GM engineers ordered special batches of PIB-free E85, but in the real world the E85 still becomes contaminated with PIB because the entire fuel refining and transport infrastructure has traces of it. Still, with this very low PIB concentration E85 deposits can still occur at similar rates.