You need to upgrade your fuel tank. E85 and steel don't play well with electric fuel pumps. This is one reason the EPA regulations for flex-fuel vehicles that can run E85, require a composite fuel cell.
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02:59 PM
3.1 88FieroGT Member
Posts: 233 From: antigo, wi, usa Registered: Jun 2010
^ Really, I'm not so sure if your right.... Mitsubishi Evo's have sheet metal gas tanks and they run E85 all the time...I helped put in a DW300 in my buddy's evo and he hasn't had any issue's so far.
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04:16 PM
3.1 88FieroGT Member
Posts: 233 From: antigo, wi, usa Registered: Jun 2010
^ Really, I'm not so sure if your right.... Mitsubishi Evo's have sheet metal gas tanks and they run E85 all the time...I helped put in a DW300 in my buddy's evo and he hasn't had any issue's so far.
I guess maybe the EVO tanks are isolated better from the chassis than the Fiero one is then. But E85 is more conductive, and having the steel tank grounded well to the chassis, will create a very good place to short the fuel pump electronics out.
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04:50 PM
darkhorizon Member
Posts: 12279 From: Flint Michigan Registered: Jan 2006
I guess maybe the EVO tanks are isolated better from the chassis than the Fiero one is then. But E85 is more conductive, and having the steel tank grounded well to the chassis, will create a very good place to short the fuel pump electronics out.
There is a lot of truth to this... Testing is still ongoing.
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05:07 PM
3.1 88FieroGT Member
Posts: 233 From: antigo, wi, usa Registered: Jun 2010
sending units are not the issue.. the pump is going to be grounded via the wiring no matter which way you look at it.
The issue is the tank being grounded, which creates a potential "short" per say from the positive wire (or in our case the positive brush inside the pump) to the outside boundary of the fuel tank.
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05:25 PM
Blacktree Member
Posts: 20770 From: Central Florida Registered: Dec 2001
I think he was referring to coating the outsde of the tank. Then you would just need to have an insulated pass through for the ground wire to the pump and float.
sending units are not the issue.. the pump is going to be grounded via the wiring no matter which way you look at it.
The issue is the tank being grounded, which creates a potential "short" per say from the positive wire (or in our case the positive brush inside the pump) to the outside boundary of the fuel tank.
Alright I get this but then why is it that the fuel pump doesn't blow when using reg. gas? Is there something in E85 that cause's this?
Originally posted by 3.1 88FieroGT: Alright I get this but then why is it that the fuel pump doesn't blow when using reg. gas? Is there something in E85 that cause's this?
Ethanol is more conductive than regular gas. It has a much higher dielectric constant. Gasoline is 2.0 at 70F, E100 is 24.3 at 77F. So E85 would be somewhere around 18-19.
Assuming you want to run the same injector duty cycle, and assuming you want to run similar mass air flow rates, injector flow rate must be scaled in proportion to the stoichiometric ratios of the fuels.
14.7:1 gasoline
9.7:1 E85
Fuel flow rate will also be scaled, so you need to check the flow rate versus pressure graph of the pump you're using, and see if you still have enough flow rate for the fuel rail gage pressure at maximum boost.
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10:31 PM
Aug 25th, 2011
buildamonster Member
Posts: 196 From: greenfield,in Registered: Nov 2005
I run E85 and have a sump added on for my A1000 fuel pump. The inside of the stock tank is coated with plastic from factory. There is no need to worry about it rusting from e85 unless it's damaged or scratch some how. I ran a cheap e-bay 255lph pump for a long time no issue. I don't know why the other guys are having problems.
