Thanks for the heads up.

If your ever in Skokie IL, the Shell on Howard and McCormick intersection has kept my injectors clean.

 

Thanks man. The E85 Station in Hoffman, off Higgins before you get to Sears HQ has kept mine clean as well. I always fill at the station but use the Crystal Lake on one on weekends occasionaly because it is near home.

The station on Hoffman I had 6 months of use from with no other stations in the mix and never had a problem. Two to three tanks from Crystal Lake and bam, clogged injectors. So strange.

 

I have this tar like residue on my FIC 2150's after ~6k miles.

unfortuantely the 2 e85 stations are supplied by pearson fuels.

My location is in San Diego, Ca.

My car is an '03 & the only additional fuel lines that have been added are for the double pumper.

 

Try calling Pearson Fuels HQ and direct them to this website/thread. See what they are using for the gasoline component and if/what they are using for additives. They may be unaware of any issues and might be able to get some tech help.

How old are the two stations you buy from?

 

Well, after all this discussion & reviewing this issue for over 1 year I pulled my injectors to inspect
1 year’s worth of full time E85 & approx 6000 miles. (Never switched to 91) Here are the results ( I was expecting worse for sure)

All fuel purchased from Pearson Fuels

Peace

 

Some were discussing the difference between type of injector (ball and seat, etc) and the build up, but I really think there isn't much of a difference.

Merely soak the tip in some gas and it will go away. It is dependent on where you get your E-85 from, and it appears that your place is using the right type of additive package for ethanol. Few others weren't so lucky.

 

Wait.... now I know that the mixing of e85 can either go great or very bad... very quick. But in order for Pearson or any of the other e85 suppliers to check their product would call for Flexfuel cars to be showing the same issue. It's kinda hard to say your product sucks when non Flexfuel cars are using it. There could be some ecu logic that helps them burn this goop off that we are seeing. But its still good to bring this up to them. ( I think these additives should not be there but... we'll see as time contuines. )

 

subscribed

 

This is somewhat true, but also realize that we are seeing this type of build up in a high heat and higher flow environment. The question of flex fuel cars was brought up a few pages ago and is still a valid argument, however you must think about what is different between the two cars. I am a believer that a certain type of injector (pintle, disk, ball and seat, etc.) are more prone to the buildup. Another point is that how often is the build up seen. Flex-fuel cars are switching back and forth between 93-87 and E-85, and as shown, the "gunk" is soluble in normal petrol. The problem is most likely rare, confined to stations who mix their own additives on site, and its effects are masked by the fact that very few people run E-85 round the clock. Whenever they make to 93, the evidence of the problem is washed into the combustion system and lost.

 

Hi,

I don't post often on this particular forum but I just came across this thread and the other one in the Engine / turbo / drivetrain section. I am an engineer, and I have been following industry developments in alternative fuels.

I doubt many of you are aware of this, but GM had a production port injected turbo flex fuel engine all the way back in 2007. It was a Saab variant of the Ecotec engine family. Saab did extensive testing on a lot of boosted E85/Flex fuel issues and published some work on it. See Bergstrom, "The New ECOTEC Turbo BioPower Engine from GM Powertrain," 2007 and Bergstrom, "Alcohol Based Combustion Engines - Challenges and Opportunities," 2007. Deposit formation is one of the dirty little secrets of E85; another is pre-ignition.

GM found the exact deposit problems many of you are experiencing. I have read a lot of different ideas on here about the nature of the problem and I have read a lot of speculation about solutions for it. Here is what we know for sure about the deposit issue, based on GM's internal research.

Chemical Origins of the Deposits

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.

A lot of people on here have speculated something along these lines.

Effect of Drive Cycle

Deposit formation is highly dependent on vehicle use and overall drive cycle. This whole issues is complicated, but aside from the makeup of the actual E85 blend, drive cycle is the #1 factor in these deposits.


Bergstrom, "The New ECOTEC Turbo BioPower Engine from GM Powertrain," 2007, Internationales Wiener Motorensymposium 2007, p. 29

On the left is a multi-hole type (not pintle type) fuel injector after 15,000 km running a GM in-house designed drive cycle to simulate major stop-and-go city driving. On the right is the same type of injector after 60,000km in a high-speed (mostly highway) drive cycle. Both engines were running the same commercial E85 blend in Sweden, consisting of 95 RON fuel and denatured ethanol.

Drive cycle variations may not explain absolutely everything but it is a reasonable hypothesis for why two vehicles running the same E85 blend can have such variability. This can also partly explain why somebody doing a lot of highway driving (rural driver or suburban commuter) who always runs E85 may never experience noticeable deposits.

Using Fuel additives and Normal Gasoline blends

There are a lot of fuel additive blends out there and they change all the time so I can't speak for all of the various formulations. What we do know based on GM's research is that PolyEther Amine or "PEA" , which can/used to be found in Techron products, cleans valve deposits but does not clean injectors with this problem. In fact, too much of fuel system cleaner could make the problem worse.



So how do we clean up the deposits if an engine is prone to them for whatever reason? Put "normal" gasoline blends in the tank and it will go away within 1 tank. You don't even need to pull the injectors.



Most of you already knew that. It's not really news; it just confirms with reliable sources what has been widely understood.

Conclusion

So yes, I didn't have any earth-shattering solutions to present, but I did clear up some of the mechanisms for this deposit formation. The deposits are caused by the gasoline portion of E85. The two biggest factors in deposit formation are the additive mix in the fuel and the way you drive the vehicle. Fuel system cleaner products are innocuous at best, counter-productive at worst. The type of injector or fuel system you run might matter some but they are not part of the mechanism of deposit formation.

So if you figure out that your engine is prone to these deposits, be mindful of stop-and-go traffic and put gasoline in your engine sometimes to clean it out.

Hope that helps.

 

Thank you very much for gathering that info up and posting it here... explains alot. I planned on taking my injectors out a regular interval, maybe I'll just run a tank of pump gas through it every so often, but I'd rather visually confirm so maybe I'll just buy up a case of injector o-rings and plan on it anyways.

 

Yes, for sure, looks like good info. I hope youre correct about the Poly Iso Butylene.

I was concerned that the ethanol was deteriorating the insides of the fuel system.

Im going to pull my injectors out this morning & take a peak again after another years worth of ethanol usage

Joe

 

Thanks for the post. Very good reading.

 

Thank you for good info.

 

Great info, I knew there had to be an OEM that had experienced this and did a study on it! Great find and great information!