Have you been happily running an eFlexFuel kit and just now develop issues? This troubleshooting guide will help us determine the cause of the problem. Carefully follow this guide and call us at 1-833-539-3835 or email us at support@eflexfuel.com with any questions.
Symptoms with eFlexFuel Control Unit plugged in:
- Misfires, rough idle, not all injectors are firing, vehicle may not start, unusual fueling characteristics
Running the vehicle with the Bypass Module installed & inspecting the eFlexFuel Harness
The Bypass Module is a passthrough "dummy-plug" that completes the injector wiring circuit without any signal change, mimicking stock injector wiring. A Bypass Module is included with every eFlexFuel kit shipped in the USA.
- With E10 (normal gasoline) in the tank, verified via eFlexApp if needed, install the Bypass Module in place of Control Unit. Try starting the vehicle.
→If the vehicle demonstrates the same issues with the Bypass Module plugged in:
There is an issue with the harness and the injector wiring circuit is not complete:
- This is often caused by a loose pin/plug on the eFlexFuel harness - the wires did not clip into place during the initial install. Double check all pinned plugs to ensure connections are tight.
- This can also be caused by a damaged harness. Inspect the harness for any pinches or other signs of physical damage. If a damaged harness is found, this is the likely cause of your issues and a replacement harness will be required.
After checking all wiring, if the vehicle still exhibits the same issues with Bypass installed: Try removing the harness and plugging your OEM harness directly into the injectors:
- If the problem persists without the eFlexFuel harness installed, the vehicle has some other issue - possibly needing a new coil pack or spark plug.
- If the problem goes away without the eFlexFuel harness + Bypass installed, there is an issue with your eFlexFuel harness.
→If the vehicle operates properly with the Bypass Module plugged in:
Leave the Bypass plugged in and Contact Us with a warranty request at support@eflexfuel.com We have a 5-year warranty and stand behind our products because of the proven reliability. We will run a full inspection & test on your Control Unit and replace it if a normal use failure confirmed.
Still have questions? We are here to help!
- First, try visiting the Customer Support Center at support.eflexfuel.com and searching and/or browsing our troubleshooting guides. Most answers are there!
- Email us at support@eflexfuel.com
- Call us Mon-Fri between 9AM-5PM PT at 833-539-3835
Thank you for joining the #E85Movement!
We hope you make the most of your additional torque and horsepower. We invite you to follow us on Facebook (eFlexFuelUSA) and Instagram (@eflexfuel) to join a community of likeminded individuals. Most importantly, have fun and enjoy your drive!