This guide is intended for vehicles with larger injectors installed that operate properly on gasoline.
⚠️Symptoms: Idle issues on E85 / high ethanol blends but no idle issues on gasoline. Vehicle drives normally on both fuels when under load.
Correct injector deadtime / offset is critical when running larger injectors. Check your injector manufacturer specs for the correct deadtime - many include this in the spec sheet. If you locate your recommended injector deadtime / offset, skip to Step 5.
Step 1
Plug the Control Unit into the eFlex Harness while E10 is still in the tank. If the vehicle idles properly, continue to step 2. If you still have idle issues with E10, visit our Poor operation troubleshooting guide here: support.eflexfuel.com/hc/en-us/articles/15875889533852
Step 2
Get the Ethanol % in your fuel up to ~E60 or higher.
Step 3
Connect the eFlexTuner (eflexfuel.com/us/eflextuner) software to the eFlex Control Unit via Windows laptop.
- Disconnect phone from eFlex Control Unit first (it only supports 1 Bluetooth connection)
- Once phone is disconnected, connect the laptop to Control Unit via Bluetooth settings first, then connect within eFlexTuner software.
Step 4
While idling, watch the ECU Pulse In. Verify that the Pulse In jumps up and down during rough idle:
Step 5
While idling, select the “Injectors” tab. Make .05 ms adjustments to injector deadtime until ECU pulse in is stable:
Step 5.5
If adjusting dead time has done the trick, select “Device” at the top, then “Write permanent tune”. This will write these updates to your device permanently. The next time you log into your eFlexApp via phone you will be able to name and save the tune.
Step 6
If idle has improved but is still rough, enriching the fueling at idle can further help. Try changing the fueling at idle to around 120-130 (this indicates a 20-30% additional ethanol enrichment at idle). To do this, look for the cursor of where the engine idles in the fuel map and change these figures.
The above steps should solve this issue. If the above steps are followed and the vehicle still idles rough to the point of dying, please record video and send to us so we can further analyze and develop a solution - we are here to help!