TwinTurbo.NET: Nissan 300ZX forum - My E85 conversion post
People Seeking Info

Subject My E85 conversion post
Posted by komplexZTT on November 19, 2020 at 9:09 PM
  This message has been viewed 869 times.
Message Never put much thought into E85 before, but was looking into fuel pumps and ended in the thought process of, well if I do X, then I only need Y and Z… and sold myself on going full E85/flex fuel. I have two E85 stations not too far from my house, and one is even on the way to work, so hopefully it stays that way for the foreseeable future to enjoy the benefits...

There is scattered info about that I’ve found, and several ways and parts options to do it, so here is what I did. Disclaimer – my engine bay and body look 30 years old…but one thing at a time.

Replaced ALL the rubber fuel lines with Gates 5/16” Barricade fuel injection E85 compatible hose. Fuel lines being 30 years old, it’s a good piece of mind. I replaced all the engine bay hose clamps last year with the double spring (tired of winter fuel leaks), so re-used those.

The lines between the tank and body hard lines were not too hard to do – I think 2+2 might have more room under there compared to coupe (as well as gas tank completely behind the read sub frame, wide open).


Went with a single Walbro 485 pump (so small and light compared to factory pump). Made a simple bracket from stainless to attach the fuel pump and used Gates 5/16” submersible E85 fuel hose to connect. I bought the Walbro installation kit which also comes with a nylon hose, but it was too long and made for larger diameter hose barb than what is on the stock fuel pump hanger. I removed the factory wiring on the bottom side of hanger and soldered in the Walbro connector pigtail.

Stock pump

Ended up shortening hose and bracket about half inch or so from this picture, and moved the connector on the inside of bracket.

On the top side, I ran a new 14AWG wire to body ground and spliced into couple inches of factory wiring on top of pump hanger (and removed the FPCU). I think the factory power wire looks big enough overall, and only a few inches of downsized wire at the topside of hanger. Will see how wiring holds up.


Went with a TOMEI adjustable FPR since I wasn’t convinced the stock FPR could properly handle the flow/pressure from Walbro 485 pump, also removed the fuel damper. Got a new OEM fuel filter and relocated it below clutch master cylinder. Moved the wiper box into the wheel well, and made a bracket for the FPR to use the wiper box mounting location. The ethanol content sensor is on the return line after FPR, attached to fuel pump bracket bolt. Used GM quick disconnect to 5/16” barbs on the ethanol content sensor. Previously had my ignition box and boost solenoid in that area, so relocated those to where fuel filter used to be.


Installed the Zeitronix ECA-2 for ethanol content monitor/display. The main box is in the radio area (wired to radio ignition power) and the gauge is in the center console armrest, pop it up and take a peak after fill.


For ECU, went with the SZ flex fuel tune and map switcher using factory clock. I had a audio AUX-in jack and USB jack in the clock location, moved the AUX to center console armrest, and just removed the USB. Adjust H/M to select map to match ethanol content (map 6 for 6x%)


Started up first try and ran completely normal, couldn’t even tell I did anything (until you get on it).
I used to spin tires in 2nd gear 16psi 93 (SZ chip), but once I got new wheels/tires about this time last year, they just gripped. After the E85 conversion (running ~60%), no change to boost controller, it’s spinning tires again, so definitely making more power with just the gas/tune. Only been a few weeks, but so far so good. Exhaust stinks less with E85, so that is a plus too.

Queue up people on I should have gone Haltec... =)

Also got around to installing my fender braces and headlights that have been sitting in the closet. Can definitely tell the fender brace is working when coming into my driveway (awkward hump) – front end used to feel like a worm going in, now it feels flat. So much organic debris came out of those fenders,lol.



Fun Times!

2+2=4; 2+0=2; 4>2 : 2+2 > 2+0.

Follow Ups  
Post a

You cannot reply to this message because you are not logged in.