Motiv Flex Fuel Installation Guide

[JOEinSD]

My ECA voltage is showing 4.05, and ethanol is pegged at 100%... and wiring seems to be good. Suggestions are welcome.

Bad module? This one is part of the first or second batch from almost exactly 2 years ago. I’m just now getting around to getting this installed.

 

[martymil]

most likely, but test the wiring with a multimeter, check for wire damage and check earth wire on ethanol sensor.

 

[AddictedToBoost]

Now that I have a new throttle body, back to the FF issue. Motive sent me a new module. When I install it, voltage reads above 4v and E content pegs at 100%.
With the old module plugged in, it reads around 1.5v and 25% E which is where it should be, until I floor it and it pegs to 100% E around 4.4v and stays there.

Is there maybe something I need to do to have the new module read correctly? I tired driving around and shutting off the car for a few minutes and restarting it but no change.

The only thing that has not been replaced in the FF system is the sensor. So I am leaning this way but wanted to know what your thoughts are?

I am having this same exact issue, what did you have to do to resolve this voltage spike on WOT?

 

[AddictedToBoost]

My ECA voltage is showing 4.05, and ethanol is pegged at 100%... and wiring seems to be good. Suggestions are welcome.

Bad module? This one is part of the first or second batch from almost exactly 2 years ago. I’m just now getting around to getting this installed.

Did you ever find a solution to your problem?

 

[NoGuru]

I am having this same exact issue, what did you have to do to resolve this voltage spike on WOT?

It's not fixed yet. Motive is looking into a solution still.

 

[AddictedToBoost]

It's not fixed yet. Motive is looking into a solution still.

What have you tried replacing so far? MOTIV Flex Fuel Box and harness ? Hobbs switch if you're running a Stage 3 LPFP? Now you're giving me doubts that a new harness and flex fuel box might not fix my problem with the voltage spiking and E content jumping up to E100 and staying there during WOT but normal cruising it's fine.

 

[NoGuru]

What have you tried replacing so far? MOTIV Flex Fuel Box and harness ? Hobbs switch if you're running a Stage 3 LPFP? Now you're giving me doubts that a new harness and flex fuel box might not fix my problem with the voltage spiking and E content jumping up to E100 and staying there during WOT but normal cruising it's fine.

I did replace the wire harness and the FF module. I'm not running a hobbs yet. Need to get this resolved so I can install my port injection.
Motive is making me a new harness to try. I will post my results when I test.

 

[AddictedToBoost]

I did replace the wire harness and the FF module. I'm not running a hobbs yet. Need to get this resolved so I can install my port injection.
Motive is making me a new harness to try. I will post my results when I test.

Have you tried swapping old and new FF module? Did one work better than the other? I have a new wire harness on the way I'm going to try replacing and cross fingers it will fix the issue. I'll keep you all updated with results.

 

[NoGuru]

Have you tried swapping old and new FF module? Did one work better than the other? I have a new wire harness on the way I'm going to try replacing and cross fingers it will fix the issue. I'll keep you all updated with results.

Yep, tried every combination. The new module will only read 100%E. I am sending all the new hardware back after I receive the new Wire loom. If it does not work with my old hardware I will test with the new stuff as well before sending it all back.

 

[AddictedToBoost]

Yep, tried every combination. The new module will only read 100%E. I am sending all the new hardware back after I receive the new Wire loom. If it does not work with my old hardware I will test with the new stuff as well before sending it all back.

Did you remember to reset your adaptations in MHD after doing so?

 

[willQ]

hey guys

I had just dealt with a similar FF issue. I've been running FF for about 5 months with no issues what so ever. yesterday, I did a WOT pull in 2nd under a bridge for fun. right after I pass under the bridge, E-reading soars to 100% and ECA to 4.1-4.5. but when I come to a complete stop (intersection/stop sign), readings go back down to normal and ECA reads at 0.74v. As soon as I put a little load on or go over a tiny bump, E jumps to 100% and ECA to 4.1-4.5.

I limped it home last night and took a peek this morning hoping it was just a loose wire or something.

checked all connections and wiring. nothing loose. With the car on while looking at my MHD tablet, I physically shook the FF box and rustled around the wires to see if it would get any better/worse.

after about 5 mins of sporadic idling and wild E readings, tapping on the box and shaking it up, the idle finally calmed down, ECA is stuck at .74v and reading 11% as it should be. drove around for about 15 minutes around the neighborhood and the FF is functioning as it should and all readings stayed the same.

I don't have an explanation of how/why it happened and how the FF 'fixed' itself?


hope this helps someone!

 

[NoGuru]

Make sure and email Motive to let them know about these issues. If no one tells them they won't know there could be a problem.

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[NoQuarter]

Where you guys getting your +12v from?

 

[NoQuarter]

An electrical DIY install that works a long time then not is often a power connection issue. Be sure to change your source or ground while troubleshooting.

Alligator clip that power connection to the battery post there in the engine bay

 

[fmorelli]

An electrical DIY install that works a long time then not is often a power connection issue. Be sure to change your source or ground while troubleshooting.

Alligator clip that power connection to the battery post there in the engine bay

This is wisdom right here. Grounds are a big issues on cars, especially as they get older. And some things are ridiculously sensitive about resistance on the circuit...

Filippo

p.s. You can always install pink slippers if nothing else works. Ask @matreyia specifically where - he might be able to help out

 

[NoGuru]

Where you guys getting your +12v from?

Using a posi tap for power, and I have retapped this wire. The ground is shown next to the washer fluid funnel.
I want to try grounding to the little part sticking out next to my air filter but I can't seem to find the right size screw that fits it. Any other ideas are welcome.

 

[AddictedToBoost]

Yesterday I replaced the flex fuel module with the updated version in my dme box. I haven't replaced the wire harness yet with a new one. I might do that today but what i did notice was that the voltage and ethenol content would spike from E65 to E100 during WOT but go back down to E65. Same issue with the voltage it would spike up to 4.43 and go back down to normal readings. It's gotten a little better but still not working 100% the way it's supposed to. The readings aren't getting stuck anymore like they were before with the previous motiv flex fuel module.

 

[AddictedToBoost]

Using a posi tap for power, and I have retapped this wire. The ground is shown next to the washer fluid funnel.
I want to try grounding to the little part sticking out next to my air filter but I can't seem to find the right size screw that fits it. Any other ideas are welcome.
View attachment 37433View attachment 37434View attachment 37435

Do you suspect it's a bad ground?

 

[langsbr]

I had some similar voltage and content fluctuations and I moved my ground to one of the shock tower nuts. I scraped away the paint on the body tho to endure a good connection. No issue since.

 

[NoGuru]

Do you suspect it's a bad ground?

No, but moving it to a new location can rule out one more thing.