Simple solution to rough start tundra flex fuel

Before you think I am crazy just try this, it works for me. Just press the gas peddle a little while starting the first time in the cold mornings. Like I said it works every time for me.

 

Pedal.

 

Considering these are all electronically controlled and the pedal is connected to nothing more than a wire, hard to see how this would make a difference - but I’m glad it’s working for you!

 

The pedal is connected directly to the ecu and the ecu controls all aspects of the startup process. No real surprise that the is software logic that changes some variables when the pedal is pressed. Most ecus have a provision for flooded starting. Pedal to the floor and ecu stops injecting fuel. It was designed that way because in the carb days that is what users did with a flooded engine.

 

The computer is going to do what it thinks is best until the engine runs. That’s how it’s programmed. Modulating the pedal isn’t gonna change anything. Same reason holding the key doesn’t control how long or short the starter spins. The computer is in control.

it’s true in some vehicles pressing the pedal 100% will prevent it from firing as a safety feature. The computer thinks the pedal is stuck and is avoiding redline on startup.

 

I don't know how the computer works or what it works. And I don't know what the gas pedal does when I mash it. All I know is that I mashed down a little bit on the gas pedal and I've been having trouble with it starting and since I've been doing that it works just fine. It did it again this morning and it was about 18 to 20° and it started right up but it did blow some black smelly smoke out the exhaust but it started up immediately

 

If you having hard starts with a flex fuel and smelly smoke in the morning, there is a good chance that your ethanol reading is incorrect in the ECU. This is common in the winter and leads the ECU to believe your fuel has a higher percentage of ethanol in it than it really does. Because ethanol has a lower energy density than regular gasoline, more fuel is required to make the same power, so your ECU adds extra fuel. When the motor is cold in the morning and already running rich, it adds even MORE fuel to make it EXTRA rich, causing the hard start and stinky smoke out the exhaust.

Search up flex fuel ethanol reset here on the forum and you should find an argosy of information. I believe the dealer needs to reset it via tech stream but there may be other ways. Personally, I don't have a flex fuel and don't have to deal with it, but it is a common issue, easily resolved. For a while, anyways...

 

I purchased the Launch X 431 Elite on Walmart.Com the one for Toyota and Lexus,scroll until you find it. It was $189.00 free shipping. It was delivered yesterday on 1/15/25 I have already reset the fuel mixture from 85 to 0. If you have read these posts you understand. This morning it started like new. It was 20 degrees. Spend the 189 instead of a 1000 or more to the dealership...

 

Does this mean the mashing pedal method stopped working at some point?

 

Hopefully it means he fixed it the right way But I, too, am curious if mashing the pedal quit working...

 

The gas pedal trick still worked it started up with no long start but it was blowing black smoke and idling very rough which I thought meant that it was mixture was set to Rich which it was and caused it to use more gas. So I decided to go with the launch scanner and it worked great. My son-in-law's a computer guy so he uploaded the new updates and all that stuff and had it fixed and the mixture set back to zero in about 45 minutes

 

I bought this scanner to check and reset the alcohol density. What are the steps to read and clear the density back to 0?

$159 2025 LAUNCH Creader Elite OBD2 Scanner for Toyota Lexus, Full System Bi-Directional Diagnostic Scan Tool, All Reset Service Code Reader, Battery Registration,ECU Coding, AUTO VIN,Lifetime Fr-ee Update

Amazon.com: 2025 LAUNCH Creader Elite OBD2 Scanner for Toyota Lexus, Full System Bi-Directional Diagnostic Scan Tool, All Reset Service Code Reader, Battery Registration,ECU Coding, AUTO VIN,Lifetime Fr-ee Update : Automotive

 

Search tundra forums. Go to 2nd gen tundra. Follow the thread Reset flex fuel alcohol density using bi-directional scan tool and it will tell you step by step what to do