Ted B

iTrader: (6)

I'm beginning to suspect the same. I've bought my fuel almost exclusively from one place. I'm going to evaporate a few gallons and have a good look at any residual remains.

xxNosTankxx

iTrader: (6)

I ordered a set of Precision 1000's to run 93 with my upcoming setup. I'm like 99% sure it said on the box "Not for use with E85" but I'm not positive. Later I'll dig them up and finds out...

Ted B

iTrader: (6)

"There is also a problem where Gasoline, MTBE, Ethanol, and Water come together. This combination can cause formations of a thick, gooey, black material that wreaks havoc on fuel systems."
Enertech Labs


"Examination of the injector tips revealed fouling with a gummy, black deposit that restricted the fuel flow and the ability of the injector to atomize the fuel properly for complete combustion in the cylinder. The exact cause of the deposit is being investigated."
E85 Powered Trucks


I feel is the most likely explanation as to why some experience these black, gummy deposits and others do not:

"In many cases, existing petrol, diesel, or other hydrocarbon fuelling systems may also be used to store and dispense fuel ethanol. An existing underground storage tank can be used to store E85/95 if the tank is either metal or fibreglass that is certified for E85/95. If another type of fuel was stored in the tank that will be used for the E85/95, it must be cleaned because storing petrol underground causes some particulates to settle out and form sludge. Introducing alcohol into these tanks will place this sludge into suspension and will lead to serious problems."
Storing_and_Dispensing_E85_and_E95.pdf

1QYK9

iTrader: (52)

FWIW...I have been running PTE 1000cc injectors (not blue tops) for over a year now on E-85 and haven't had ANY issues. I barely drive the car (once or twice a month on short trips) and so any ill affects of the E-85 on the injectors should be even more pronounced. My Walbro 255 fuel pump should be hating life two but it is still good to go. Maybe I am lucky.

Ted B

iTrader: (6)

I have a good hunch that it comes down to the particular retailer. It is said that many E85 stations do not have a clean bill of health when it comes to storage and dispensing equipment, possibly because there is no mandate. I suppose many of these retailers simply began filling tanks with E85, without cleaning the tank or determining if it is compatible with ethanol.

I could be wrong, but that seems to be the most plausible explanation.

john.schuber

iTrader: (3)

It is a shame that Deatschwerks does not offer 1000 or 1200cc injectors with all the positive things people are saying about them. This leaves all the stock, bbk, green, and maybe even the red turbos who want to run e85 out of the mix, since 880's are to small and 1600's are to big... hopefully someone can chime in with information on if there in-development or the reasoning behind Deatschwerks choice.

TalonFiero

iTrader: (18)

I just swapped out my PTE 1000cc injectors after 45,000miles and three years of E85 only, never anything but E85 on these injectors from day one. They worked great and are still in awesome shape, I simply needed more fuel so went with larger injectors.

Also my Walbro 255 pump has been running E85 for the three years and 45k miles too with no issues.

CO_VR4

iTrader: (83)

There is a long discussion on CoDSM about this issue, with participation from an industrial chemist. Summary: E85 has a gasoline component. Crappy gasoline in the E85 carries a gummy substance which has a crossover point that allows it to precipitate out and produce the "tar" at the injector. The proposed solution is to change the crossover point by adding a little amount of "better" gas to the blend when you fill up (changing the crossover point higher), or get another E85 source that uses a better gasoline component.

David Buschur

iTrader: (53)

COVR4, yes, agreed, after reading through that very good thread on CODSM that seems to be the conclusion. The solution though seems to be simply to run a tank of normal unleaded gasoline through the car from time to time and it cleans the injectors, valves and combustion chambers right back up.

CO_VR4

iTrader: (83)

That's true, Dave. If you want to avoid the problem in the first place, the addition of a small amount of race gas or high quality pump gas (a gallon or two) looks like it will change the cross over point enough to prevent the problem in the first place for those who want to continue to use the E85 that has the gum characteristic. The "gum" is highly dissolvable in normal gas, but not in E85..

Many people use sources for E85 that don't demonstrate this characteristic, presumably because the gas component they use does not have the suspended gum in it. I know of several people who buy the race E85 and none of them have this problem.

Either way, it's good to have a "fix"

jid2

iTrader: (62)

Yeah that chemist did everyone a favor by figuring out the true root-cause of the issue. I plan on pulling my injectors after a little more use to see if my E85 source is tainted, crossing my fingers for the good stuff.

DynoDude55

iTrader: (20)

Good info here! I have been running E-85 on my IX for well over 1800 miles with Precision 1200cc's and recently tore my engine down for a new build. I noticed this "black tar" coated on top of my intake valves which only have 1800 miles on them as well. I religously used E-85 from Hill Petro in Arvada, CO because they blend the full 85% year round and never switch to the winter 70% blend. Makes me wonder what type of gasoline they are blending it with.

Ted B

iTrader: (6)

I found this out recently when I attempted to remove the gum deposits on my injector tips and intake valves with ethanol - no dice. With gasoline however, it cleaned up fairly easily. If putting gasoline through it from time to time does a good job of cleaning any buildup, that's a cheap remedy.

I had my injectors flow tested to gauge the effect of the gum around the tips. The performance of the injectors was unaffected, so that is good news.

As all available evidence indicates, the occurrence of the gum deposits seem to be vendor specific. I dispensed 2 gal of E85 from the suspect vendor, poured it into a bucket, and let it evaporate. As of now, there is less than 1/2 gallon remaining, and the liquid has gone from virtually clear to that dark amber tint characteristic of the gum. I'll post a photo when only the resin remains. Meanwhile, Drifto gets his E85 from a different vendor, and his engine seems to be clean.

jid2

iTrader: (62)

As noted in the chemist thread the gum is clear or at least transparent in raw form. The black color comes from particulates picked up in the intake system. So your left over residue probably won't be black.

Ted B

iTrader: (6)

The gum is undetectable in the fuel because since it is dissolved by the fuel, the solution is clear.

When the fuel is sprayed from the injector, it atomizes. The gum cannot atomize, so it stays behind and just builds as the process continues. It's almost black right at the tip of the injector and everywhere else. If it becomes black as a result of the heat or if it starts that way, I do not know at this point.

What I am doing by evaporating the fuel is concentrating the gum. The fuel evaporates. The gum cannot evaporate. Fresh out of the pump, the liquid is turning more amber as it evaporates, so I do not see how what's left could possibly be clear.