2018 FFV cold start issue

2018 Tundra with 27k miles, 5.7 FFV

On the first crank of the day motor spins over fine but once it goes to fire there’s a pretty noticeable stumble. On a cold morning (40’s for us in FL) it’s even more of a stumble. Once warm it’ll crank fine but I have noticed that period of when it shuts off and crank fines has gotten shorter. This started in conjunction with a poor battery and I was hoping it was bad battery. First trip to dealer no results or service performed. On second trip to dealer they replaced battery after some fighting but past two trips they deny there’s a stumble on a cold crank. Helen Keller can hear the stumble but Toyota service advisors can’t. They just want me to go somewhere else or just deal with it. I can hear fuel pump kick in immediately when key is clicked on fwiw. Im pretty certain my problem is the common ~2012 to 15 FFV issue being stuck in e85 mode while on 87. I have never run e85.

My questions are: What should the alcohol levels be on e85 vs 87 when scanner is hooked up at the dealer. And once warm, even though it’ll crank fine, will the scanner still know if it’s stuck in e85 mode and the alcohol levels be false or will I have to leave it again overnight just for them to hook it up on scanner before it’s initial crank?

Thanks in advance.

 

Does disconnecting the battery return it to conventional fuel mode?

I don't know the answer bat am interested in the topic.

 

From what I’ve gathered, no it doesn’t. Requires a reflash. Problem has been going on for a 4+ months now and battery was changed last week with no correction in the stumble.

 

I don’t get why those idiots won’t even check the alcohol density percentage? I’m sure it needs a reflash. Mine did and it runs perfect now. I’d try another dealer.

 

Was this done Under warranty? Mine is out of the 3-36 by about 6 thousand. Called to inquire and was told bring 130 bucks to diagnose said problem.... even though there is an Active TSB.

 

This should fall under 5/60k powertrain as its and ECM update for an engine related issue.

 

Mine was done under warranty.

 

I doubt that. It’s a computer reflash.

 

Yeah...a powertrain module update...powertrain key word.

 

It changes the computers reading of the alcohol density in the fuel. I hope they would cover it under the 5/60 but I’m betting they won’t.

 

Because the module being flashed is the "engine control unit". From what I recall, the FFV engine uses O2 sensor readings to monitor the %.

Please tell me how you view this not being covered under a powertrain warranty?

If my engine doesn't start because some crap readings from my ECU..hows that not a powertrain issue? The engine failed to start.

 

I just see them balking at it. But, based on this you have a very valid argument.

 

Let us know what the dealer says. I’m curious if they cover it. I hope they do.

 

Update: The service dept is ordering the parts to fix the Hard start issue per the most recent TSB.

T-SB-0166-19 December 6, 2019 Page 2 of 12 Extended Crank and/or MIL ON With DTC P0171, P0174, P0172, P0175, P1604 (Flex-Fuel) Draft - Confidential © 2019 Toyota Motor Sales, USA Warranty Information OP CODE DESCRIPTION TIME OFP T1 T2 EG1904 Reprogram Engine ECM (PCM), R & R Fuel Pump, Reset Fuel Alcohol Learn Value, and Add Fuel 2.2 89661-0C### 07 74 *A maximum of $15.00 (3 gallons of fuel) will be allowed under sublet type “GA.” Parts Information PART NUMBER PART NAME QTY PREVIOUS NEW 77020-0C170 Tube Assy, Fuel Suction W/Pump and Gage 1 77020-0C090 1 77020-0C120 1 89661-##### Computer, Engine Control – 00451-00001-LBL Authorized Modifications Labels 1 APPLICABLE WARRANTY • This repair is covered under the Toyota Federal Emission Warranty. This warranty is in effect for 96 months or 80,000 miles, whichever occurs first, from the vehicle’s in-service date. • Warranty application is limited to occurrence of the specified condition described in this bulletin. NOTE • The ECM (PCM) should NOT be replaced as part of the Repair Procedure. • Authorized Modifications Labels may be ordered in packages of 25 from the Materials Distribution Center (MDC) through Dealer Daily – Parts – Dealer Support Materials Orders.

They also Flashed the ECM today. All covered under warranty.

 

Awesome!

 

Sounds like they are doing a lot more that what they did to mine. The Flash completely eliminated my issue but maybe it will come back?

 

Good to hear. Have you driven it since the flash?

 

Just called my local stealer to have the ECU flash and the guys absolutely pissed in my Wheaties....
He said a Reflash on my '17 WOULD NOT be covered under the warranty and wants to charge me $80 for a "diagnostic charge". Could be that I didn't buy my vehicle from them but still. I am not paying for something that should be covered when the truck is still below the 60K mile warranty.
Looks like I will be calling the dealer in the next county. Not convenient but what can I do at this point.

 

Did you tell him the TSB #?

Usually that's no questions asked after that.

 

Please post the TSB # if you have it. I’ll call them back.
Thanks man.

 

Post #14

 

Thanks 14. I was so pissed, I missed it.

 

That was my thought as well. Since the re flash I've had Zero Cold Hard starts but the temps here in E Tx are in the sixties at night.