100% e85 black death

Raider

Raider

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I'm not in the loop on this and I was asksd. 100% E85 in the tank... causes the sticky "black death" locking up the high pressure pump.. doesn't occur if running a gas/eth mix. Was this ever figured out?
 
IIRC, 50% or less is the most you can go, and you needed to dump sl1 fuel system cleaner in the tank and HPFP every once in a while.
 
Mauro_Penguin said:
IIRC, 50% or less is the most you can go, and you needed to dump sl1 fuel system cleaner in the tank and HPFP every once in a while.
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I only remember mixing needed to prevent it.
 
Raider said:
I only remember mixing needed to prevent it.
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Incorrect; worst pump I've ever seen was off a pump gas only CX7 and the stock internals (which you can normally just pull out of the pump from the back without taking the retaining nut off) were seized. It was so bad, they couldn't get it unbolted from the part that bolts to the head, so that came with the pump too.

It's the oil that matters most. I'm on RP Dexos and have been full corn for a long time. Brotella will fuck your shit up right quick, and you should eventually tear it down and clean it anyways after so many miles (every oil change would be ideal but probably not required, depending).

Also being stuck in stop and go traffic may be a factor here as well (heatsoaking).

Ask some questions if you have them, happy to answer.

Mauro_Penguin said:
IIRC, 50% or less is the most you can go, and you needed to dump sl1 fuel system cleaner in the tank and HPFP every once in a while.
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There's nothing you can put in the tank to prevent/clean the HPFP. I clean my pump with lighter fluid (naphtha) and went so far as to put a full gallon of it in my tank with the fuel light on (almost empty) and it never recovered even after several minutes of idling. Also tried to "prime" the HPFP with it by draining gas out of the pump proper and refilling it with lighter fluid (and squirting it in there to "flush"). No dice.

Filling /lubing the pump after a cleaning with Redline isn't a fix either; it simply displaces most of the fuel and oil that would get in there and help prevent issues but over time it will be displaced itself, and you will wind up with sticky death (in the case of RP oils; from experience). The issues you get as a result are way more tame, however, and you can sometimes get it to kick back into action by stabbing it or bringing the revs up; just long enough to get home and clean it.
 
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Raider said:
I'm not in the loop on this and I was asksd. 100% E85 in the tank... causes the sticky "black death" locking up the high pressure pump.. doesn't occur if running a gas/eth mix. Was this ever figured out?
Click to expand...
hello and welcome to MSO, searching can yield some wonderful threads, I find it best to use Google "black death site: Mazdaspeeds.org" will filter results to here and yields this thread which is quite helpful and will answer many of your questions
https://mazdaspeeds.org/index.php?threads/some-newb-e85-questions.12189/

We also have an entire section dedicated to ethanol
https://mazdaspeeds.org/index.php?forums/mazdaspeed-3-6-e85-cornfed.115/

/S seriously though checkout that thread I linked some good info in there
 
Back with the same name, I'm the one who made the post detailing the Redline S-1 + RP Dexos fix based on (I think?) Littleloogy's evidence. Haven't touched my HPFP in 8 years. Cleaned it once with Redline, only RP Dexos Spec since then. Never had a single issue. Multiple corn stations in NY and now 5 different corn stations here in VA since moving, probably 30k miles including months and months in between on 93 after covid fucked the corn couch. Royal Purple Dexos spec is the cure, just gotta get rid of any existing death with something like the redline first.
 
Redline doesn't cure the issue, just covers it a bit. You should still clean your pump every couple of oil changes IMO (esp if you do a lot of stop and go), or at least siphon out whatever is in the pump and re-prime it with Redline to the bottom thread on the spill valve. Even if it starts to fuck up, you should have plenty of warning as it does; IIRC it starts with maybe a rough start now and then, and progressively gets worse over time.
 
I don't think Redline is the cure, I think the Royal Purple Dexos is the cure. Not so much cure as it is absolute prevention because it just seems to not break down like other oils do. I never cared enough to try any other dexos spec brand so not sure if its that or something else about the RP itself. The Redline just gets rids of whatever existing death is there really well but wont stop the actual problem of the oil diluting/separating or whatever its doing. Maybe my car is an outlier but again, havent touched the pump in 8 years, 30k miles and the only thing that has remained the same is RP oil changes. I haven't had a single rough start or any sort of fuel pump, pressure or flow issue. I've been away from the forums for so long I sort of expected to come back and have everyone blissfully running full E heh.
 
Easter Bunny said:
No need to fix the search function @Awafrican does it for you
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*Sometimes. I do try to be helpful and give folks the answers but I can't catch everyone. I've got many threads bookmarked for quick links, I should really put them into a useful threads thread like the old place had, sticky it and send it out on the welcome PM.

Now I did see one forum that's search actually went to Google with the "site:formaddress.com" filter applied to the end which I thought was great, don't remember which form I was on unfortunately.
 
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