E85 Feels like Stalling when coming to a stop to quickly

[stangman638]

Not yet, need to send another log back to tuner.

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[Diocletian]

Strange we both have May 18 builds too. Lol.

Have you had battery checked or replaced by chance?

I also have a May 18 build AND an auto and I get these same issues, I was pulling my hair out for MONTHS trying to diagnose it with Lund. Went through the same process you did. Something is up, I have a feeling tuners aren't factoring in something here.

I recently switched back to E85, even tested the gas to make sure it was good. I got no issues when driving 50+ miles yesterday but when I pulled it into my garage and quickly threw it into Park it actually stalled. Thats a first for me. I'll be switch to E85R again today and see if that helps. I have a feeling it's some weird stall speed issue that being exacerbated by the constant recalibration the sensors are doing all the time on E85

 

[Zinc03svt]

I also have a May 18 build AND an auto and I get these same issues, I was pulling my hair out for MONTHS trying to diagnose it with Lund. Went through the same process you did. Something is up, I have a feeling tuners aren't factoring in something here.

I recently switched back to E85, even tested the gas to make sure it was good. I got no issues when driving 50+ miles yesterday but when I pulled it into my garage and quickly threw it into Park it actually stalled. Thats a first for me. I'll be switch to E85R again today and see if that helps. I have a feeling it's some weird stall speed issue that being exacerbated by the constant recalibration the sensors are doing all the time on E85

Yeah it sucks! Car spent two weeks (and 2k warranty) in dealer for cam phasers. 3 days after dealer pickup on stock tune pump gas idle stumble 2x in a row. It has not stalled since dealer visit though.

I am having good luck so far keeping battery charged and check into that battery mgt thread. I unplugged both sensors off battery and fuse box. May be bad sensor/plug on this system somehow? Car has run flawless on E85 tune (bumped up idle rpm 750) for 5-6 key cycles. Fingers crossed!

Yeah that is 3 May builds with basically same problem... Crazy!

 

[Diocletian]

Yeah it sucks! Car spent two weeks (and 2k warranty) in dealer for cam phasers. 3 days after dealer pickup on stock tune pump gas idle stumble 2x in a row. It has not stalled since dealer visit though.

I am having good luck so far keeping battery charged and check into that battery mgt thread. I unplugged both sensors off battery and fuse box. May be bad sensor/plug on this system somehow? Car has run flawless on E85 tune (bumped up idle rpm 750) for 5-6 key cycles. Fingers crossed!

Yeah that is 3 May builds with basically same problem... Crazy!

I'll do that if I experience any more issues. I notice in Flex tune my voltage, according to the Mustang track apps, goes down to 13.5v most times. This morning I switched to the E85R tune, literally had zero issues after 30 minutes of spirited driving, car felt very quick and solid with no issues. I notice that I was at 14v more often than the Flex tune, and that I was idling at about 750-775RPM. I'm happy for now but we will see if anything else happens!

 

[stangman638]

Still no clue, since reflashing to stock and running 93 and than going back to E85 it has been perfect...

 

[Zinc03svt]

Still no clue, since reflashing to stock and running 93 and than going back to E85 it has been perfect...

They recommend going from stock tune to E85 tune for whatever reason. I had been flashing new E85 tunes back to back myself last fall and winter. That is when idle issues went south... ??

 

[Diocletian]

Haven't had anymore issues the last two times I drove it after going to E85R. I'll be driving it again tomorrow and definitely next week since I'll have my new exhaust on

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