Motiv Flex Fuel Installation Guide

[Jeffman]

Thanks, R.G. I’ll check for leaks when I get it installed.
Now, does anyone have any suggestions as to how best to access the tunnel area under the driver’s footwell? I now need to disconnect the short OEM flexible fuel in order to connect the Motiv short fuel line and ethanol sensor.
Thanks.

Edit: I figured it out. Removing just the bottom plastic panel beneath driver allowed me access to tunnel and fuel lines. After disconnecting short line in engine bay from hard fuel line was able to pry off the fuel line from the plastic connector attached to the tunnel. Disconnected the longer fuel line from a few of the clips heading towards the tank to create enough slack so that I could pull out the short line from the tunnel to have enough room to connect the Motiv engine bay fuel line and ethanol sensor. Then fished the Motiv line back up the tunnel from underneath the car.

 

[matreyia]

I experienced a crunching sound while installing the short Motiv Flex Fuel line. I’ve never used these kind of connectors before. I grabbed the male collar with thin vice grips and a wrench on the female side to tighten it and heard a crunching sound while tightening. Did I f something up?

I did not hear this sound when I installed.

 

[langsbr]

If mine did make a sound I couldn't hear it over my cursing the use of those fittings and their closeness to the block.

 

[Jeffman]

If mine did make a sound I couldn't hear it over my cursing the use of those fittings and their closeness to the block.

With the MOTIV short OEM hose replacement connected to the OEM hard line / LPFP Sensor, the ECA sits in the tunnel.

 

[langsbr]

With the MOTIV short OEM hose replacement connected to the OEM hard line / LPFP Sensor, the ECA sits in the tunnel.

I don't quite follow what you mean. I have the Motiv short line that replaces the stock flexible line between the fuel line under the car and the hard line to the LPFP. My continental sensor is more what I would deem "in the engine bay" than in the tunnel. I think if you have the full fuel line replacement it puts it under the car.

It just wasn't much fun tightening the fitting onto the hard line since it's so close to the block. Getting a wrench on it securely was a pain.

 

[Jeffman]

Hmm - I’ll snap a picture later showing where my short MOTIV line and Ethanol Sensor sits. I took off the hardline with LPFP Sensor to attach the short MOTIV line. It’s much easier that way (I learned this from a failed TBI line I once had installed).

Edit: here are two pictures showing where the ethanol sensor sits in the tunnel under the driver with the grey cable and orange connector leading away and up towards the firewall.

(I had just walnut blasted my intake so I still had various sensors disconnected and labeled with blue painter’s tape. Here’s the N20 TMAP hanging out with the steering rod and the driver motor mount lol. )

 

[pysical]

Anyone have a good explanation of how to route the wire from the ECA to the DME box?

 

[Jake@MHD]

Anyone have a good explanation of how to route the wire from the ECA to the DME box?

ECA should go in the DME box Make a small slice in the cable sleeve leaving the DME box (at the bottom) and route the ground wire and harness to the continental e-sensor out.

 

[pysical]

Ah, I was thinking the ECA was the piece that goes at the fuel line. Just want to make sure that cable is routed away from anything that could mess it up.

ECA should go in the DME box Make a small slice in the cable sleeve leaving the DME box (at the bottom) and route the ground wire and harness to the continental e-sensor out.

 

[fmorelli]

ECA should go in the DME box Make a small slice in the cable sleeve leaving the DME box (at the bottom) and route the ground wire and harness to the continental e-sensor out.

Just an FYI we didn't have to make any cuts in the cable sleeve (assume you are referring to the rubber bellow where the factory wiring enters the box). We used a long screwdriver, couple dabs of dishwashing soap to lube the shaft, pushed the screwdriver through from inside the box to outside (pop up the rubber bellow out of the box, makes it easier to work), taped the wire to the screwdriver tip, couple dabs of dishwashing fluid on the wire, and pulled it right on into the box. As they say, YMMV. There are a few photos here. I'm about to install small power distribution box inside of DME box as I have a few other things I want to power. We'll do the same with those wires.

Filippo

 

[NoQuarter]

Just an FYI we didn't have to make any cuts in the cable sleeve (assume you are referring to the rubber bellow where the factory wiring enters the box). We used a long screwdriver, couple dabs of dishwashing soap to lube the shaft, pushed the screwdriver through from inside the box to outside (pop up the rubber bellow out of the box, makes it easier to work), taped the wire to the screwdriver tip, couple dabs of dishwashing fluid on the wire, and pulled it right on into the box. As they say, YMMV. There are a few photos here. I'm about to install small power distribution box inside of DME box as I have a few other things I want to power. We'll do the same with those wires.

Filippo

I like that fuse block. Easier than the dongle I made up.

Getting power from the main battery/starter cable is ideal and switching it on via a relay from the DME orange power wire is the ultimate setup for this I think.

 

[Jeffman]

I completed my MHD / Motive Flex Fuel install yesterday. I had installed the ethanol sensor on the fuel line several weeks ago while I had the manifold off to walnut blast the intake and install a Mishimoto low side OCC. Before closing her up I routed the cable from the ethanol sensor up the fire wall, behind the high and low catch cans, and over to the DME box. The wire bundle just sat there on top of the DME box with electrical tape on the wire ends until I had time this past weekend to wire it in. I kept the Motive Flex Fuel ECA (the box with the USB connector) disconnected from the wire bundle until after I had prepared my custom Flex Fuel bin from my latest 93 octane and E60 bins. Once my custom Flex Fuel bin was ready I purchased the $99 MHD Flex Fuel module and flashed the bin (long write, 10 minutes, use charger). Next, disconnected the charger and battery. Finally wired in the Motiv Flex Fuel bundle, connected the Flex Fuel ECA box and fired her up. Other than needing to extend the ground wire and look at some JB4 install YouTube videos to help me with the DME connectors, all the parts and instructions of the Motive Flex Fuel kit, the MHD Flex Fuel module, and Jake’s Flex Fuel XDF and instructions for converting custom bins worked flawlessly. Now it’s tuning time!
Photos below.

I opened the DME box to look around to familiarize myself first before flashing the FlexFuel bin.

Flashing my custom FF bin. New logic, so it’s a long write. Here showing 5 minutes left (out of about 10 minutes total with the latest cable).

To feed the grey cable from the ethanol sensor into the DME box I sliced the bottom of the rubber sealing grommets closest to the firewall. I extended the grounding wire with about 5 inches wire and fished it through the rubber sealing grommet furthest from the fire wall and out the rubber sleeve to the grounding post.

Lifting the larger connector off the DME. Thanks to Sean and his JB4 install YouTube videos!

Everything all connected. You can see the Motive ECA box sitting in the front empty slot with its USB connector sitting up.

After flashing ... the moment of truth... does it work???

Ignition on before starting...so far so good. See ECA voltage, % ethanol (only have 93 octane pump =10%) now and interpolation is about 0. Looks good so far.

Engine running!
All looks okay. I’ll be reporting separately about the tune.

 

[Jake@MHD]

Nice write-up and pics Jeff Hope you enjoy tuning it!

 

[tan_rich]

For the flex fuel sensor aluminum fittings, how tight should we tighten them? They seem easy to strip.

 

[Jeffman]

For the flex fuel sensor aluminum fittings, how tight should we tighten them? They seem easy to strip.

Good question. I cranked on them until I heard crunching and my muscle memory torque wrenches told me “Tight ‘nuff”.

 

[tan_rich]

Good question. I cranked on them until I heard crunching and my muscle memory torque wrenches told me “Tight ‘nuff”.

If I cranked until I heard crunching, my sphincter would squeeze tighter than the density of a black hole :|

 

[Jeffman]

Indeed mine did LOL!

 

[NoGuru]

Any more then one good crunch and you went to far.

 

[matreyia]

Where a

I completed my MHD / Motive Flex Fuel install yesterday. I had installed the ethanol sensor on the fuel line several weeks ago while I had the manifold off to walnut blast the intake and install a Mishimoto low side OCC. Before closing her up I routed the cable from the ethanol sensor up the fire wall, behind the high and low catch cans, and over to the DME box. The wire bundle just sat there on top of the DME box with electrical tape on the wire ends until I had time this past weekend to wire it in. I kept the Motive Flex Fuel ECA (the box with the USB connector) disconnected from the wire bundle until after I had prepared my custom Flex Fuel bin from my latest 93 octane and E60 bins. Once my custom Flex Fuel bin was ready I purchased the $99 MHD Flex Fuel module and flashed the bin (long write, 10 minutes, use charger). Next, disconnected the charger and battery. Finally wired in the Motiv Flex Fuel bundle, connected the Flex Fuel ECA box and fired her up. Other than needing to extend the ground wire and look at some JB4 install YouTube videos to help me with the DME connectors, all the parts and instructions of the Motive Flex Fuel kit, the MHD Flex Fuel module, and Jake’s Flex Fuel XDF and instructions for converting custom bins worked flawlessly. Now it’s tuning time!
Photos below.

I opened the DME box to look around to familiarize myself first before flashing the FlexFuel bin.
View attachment 14097

Flashing my custom FF bin. New logic, so it’s a long write. Here showing 5 minutes left (out of about 10 minutes total with the latest cable).
View attachment 14098

To feed the grey cable from the ethanol sensor into the DME box I sliced the bottom of the rubber sealing grommets closest to the firewall. I extended the grounding wire with about 5 inches wire and fished it through the rubber sealing grommet furthest from the fire wall and out the rubber sleeve to the grounding post.
View attachment 14099

Lifting the larger connector off the DME. Thanks to Sean and his JB4 install YouTube videos!
View attachment 14100

Everything all connected. You can see the Motive ECA box sitting in the front empty slot with its USB connector sitting up.
View attachment 14101

After flashing ... the moment of truth... does it work???

Ignition on before starting...so far so good. See ECA voltage, % ethanol (only have 93 octane pump =10%) now and interpolation is about 0. Looks good so far.
View attachment 14102

Engine running!
All looks okay. I’ll be reporting separately about the tune.
View attachment 14103

Where you getting the ethenol module for mhd?

 

[Jake@MHD]

Where a

Where you getting the ethenol module for mhd?

https://bmw.spoolstreet.com/threads/n54-stock-dme-flex-fuel.1185/page-41#post-44124