View Full Version : E85 in RX7
NoDOHC
05-13-2010, 10:10 PM
So I had a few spare moments from work and I decided to do some beta testing for an air-cooled VW project (which will be running E85). It seemed an excellent idea to run E85 in my Mazda to test for startability (I had heard rumors that E85 did not start well).
The good news is that the car started just fine on E85.
The bad news is that I got approx. 300 miles on E85 before I started having Injectors sticking (this made the car not idle properly). I replaced the bad injectors and went back to regular gas, but now it appears that my fuel pump has given up the ghost.
Has anyone else experienced similar problems running E85?
TitaniumTT
05-13-2010, 10:14 PM
Ethanol sucks, that is all.
Was your fuel tank ever coated with anything?
What was the condition of the tank prior to running the e85?
The great thing about ethanol is that it's a great cleaner/sludge remover. The horrible thing about ethanol is that it works really well as a cleaner/sludge remover. It'll also melt fiberglass/epoxy coated fuel tanks.
What injectors were you running?
12arotary
05-14-2010, 09:52 AM
Ethanol sucks, that is all.
Was your fuel tank ever coated with anything?
What was the condition of the tank prior to running the e85?
The great thing about ethanol is that it's a great cleaner/sludge remover. The horrible thing about ethanol is that it works really well as a cleaner/sludge remover. It'll also melt fiberglass/epoxy coated fuel tanks.
What injectors were you running?
basically all the reasons 94octane is just better
NoDOHC
05-21-2010, 07:39 PM
I didn't do anything to the fuel system, it is bone stock.
Stock '86 460 cc/min injectors (rebuilt 30,000 ish miles ago for my NA engine and transfers to the TII since it was still NA)
Stock TII fuel rail
Uncoated and unlined fuel tank
Original fuel lines
Original Fuel pump
You get the idea.
Looking back, it was not the smartest idea I have ever had, I did prove my point though, E85 starts just fine on a low compression ratio (8.2:1) engine if you have programmable EFI. Several friends who still use carbs were convinced that E85 required at least 12:1 compression ratio to start on a 40 degree day.
I should have thought of the 20+ years of trash in my tank when I did it though.
When I get a chance, I will go ahead and replace the entire fuel system, I needed a new fuel pump at 212,000 miles anyway :)
TitaniumTT
05-21-2010, 09:29 PM
That blows, sorry man. I'd be really curious to see what's on the inside of the tank. I'd bet that the sock is clogged, the pump is rotted. I'd be concerned about the fuel lines. Cleaning them out will be a bitch and there's no real way to be 100% certain that they are in fact.... clean. Cars suck, I think I'm going to start collecting stamps or coins
AnthonyNYC
10-18-2010, 01:46 AM
So I had a few spare moments from work and I decided to do some beta testing for an air-cooled VW project (which will be running E85). It seemed an excellent idea to run E85 in my Mazda to test for startability (I had heard rumors that E85 did not start well).
The good news is that the car started just fine on E85.
The bad news is that I got approx. 300 miles on E85 before I started having Injectors sticking (this made the car not idle properly). I replaced the bad injectors and went back to regular gas, but now it appears that my fuel pump has given up the ghost.
Has anyone else experienced similar problems running E85?
I've been running E85 for a few years now with no issues. Over 50% of the rotaries in the NY area are on ethanol. I've tested the winter blends as well as the summer blends and have no issues starting in the cold.
I've gone as far as 30psi on E80 and no knock. I honestly believe ethanol is by far the best fuel for rotaries. You have to see how clean the motors are when taken apart.
I've also used E98 but that's another story....
If you have any questions let me know.
Anthony
TitaniumTT
10-18-2010, 04:36 PM
I'm considering building my FD around E85 and I don't even know where the nearest station is. I agree it does have benefits, but I still think that the car needs to be built around it. My biggest question is -
What are your EGT's like at various boost levels?
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