Car will not stay running

[Stephen@lethal]

I would say drain the E85 and swap to the 93 tune just to see if indeed its not related to the fuel. If its still doing it on the 93 tune, its a fuel system issue most likely.

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[Diocletian]

I'll try to get the last of the E85 changed, I'll be purchasing a gas can to fill with 93 to put in afterwards and try it again

 

[msweet]

When you loaded the flex tune and started the car up, was the car already warm or was it a cold start?

I had an issue once on my 16 where I went from E85R to flex, and then did a cold start. Because it was on E85 it didn't want to start first time (ambient temp was cold), so it stalled and that screwed the whole idle/throttle out of whack. After 5 minutes of starting/restarting/trying to drive, I thought maybe the learning process was disrupted because it stalled when I first fired it up after loading the tune. I reloaded the tune and it was perfect again.

 

[Diocletian]

As this car isn't my daily, I haven't tried again since I posted this. If it IS way to low on gas or a tune issue I don't want to destroy my fuel pump or anything else constantly trying to restart it. Come Saturday here is what I will try:

1. Get a gas can. Fill with 5 gallons of 93
2. Reflash Lund Flex tune(still remnants of E85 in there, I don't want to switch to full 93 tune yet)
3. Let the fuel pump prime(I believe it does this when you open the drivers door)
4. Fire it up

I checked the MAF, it looks fine. I don't believe it's installed upside-down, it's been in the same position it came from the factory. I checked for vacuum leaks, everything is all brand new and the car has low miles so everything looks ok there as well.

 

[Cobra Jet]

Have you gone into Engineering Test Mode via the main dash cluster to see if there are any codes stored there? I’ve heard that even if a code is not present in a code reader (or via tuner software) there still could be codes seen in the Engineering mode.

You stated fuel pressure is “good” - but no numbers; do you know the actual fuel psi when cranking it over or powering it up?

Have you tried reflashing the same exact tune that you had loaded right before the non-start issue? I’m wondering if perhaps there was a glitch or issue during file transfer and the reflash was corrupted.

Are you able to tell if you’re getting any spark?

 

[gixxersixxerman]

When you said you flashed the flex tune in because you want to go back to 93, were you on a E85r tune? Im assuming so and now that you are trying to flash the flex tune in its running off e10-ish setting because it hasnt learned the content. Flash the e85r tune back in drive it to the station, (youll be fine with 18 miles left, most of us go down to low single digits) then once you fill up with 93 flash the flex in.

 

[Diocletian]

Have you gone into Engineering Test Mode via the main dash cluster to see if there are any codes stored there? I’ve heard that even if a code is not present in a code reader (or via tuner software) there still could be codes seen in the Engineering mode.

You stated fuel pressure is “good” - but no numbers; do you know the actual fuel psi when cranking it over or powering it up?

Have you tried reflashing the same exact tune that you had loaded right before the non-start issue? I’m wondering if perhaps there was a glitch or issue during file transfer and the reflash was corrupted.

Are you able to tell if you’re getting any spark?

Fuel pressure is the same is always was when it worked.

I'm getting spark as it turns over and fires up

I haven't reflashed the tune, I will be doing that first come this weekend

How do you enter engineering test mode?

 

[Diocletian]

When you said you flashed the flex tune in because you want to go back to 93, were you on a E85r tune? Im assuming so and now that you are trying to flash the flex tune in its running off e10-ish setting because it hasnt learned the content. Flash the e85r tune back in drive it to the station, (youll be fine with 18 miles left, most of us go down to low single digits) then once you fill up with 93 flash the flex in.

Yeah I was on E85R. I'll keep that in mind

 

[gixxersixxerman]

Yeah I was on E85R. I'll keep that in mind

Yeah so if you check your alch% i bet it states 0 or 10% mine always reverts to it, so its basically acting like its on its 93 tune, why it wont start. You could flash the e85r tune, get the engine warmed up then flash your flex tune in, but still going to be driving around on the calibration that thinks its 10% or so until it learns it. at that point youll already be at a gas station.

 

[Cobra Jet]

Fuel pressure is the same is always was when it worked.

I'm getting spark as it turns over and fires up

I haven't reflashed the tune, I will be doing that first come this weekend

How do you enter engineering test mode?

If you have the standard analog cluster, this procedure should be the same across all 2015-2019’s:
https://www.mustang6g.com/forums/threads/engineering-test-mode.27581/


If you have the digital cluster (2018-2019), use this procedure:

I got my 2018 to work before. Here is how I did it:

Turn on the key but do not start the car. (press "Start button")

Put the display in the mode where it is blank.

Hold the "OK" key and start the car.

When the "Engineering Test Mode" shows up release the "OK" button.

Use the up/down arrows until the AFE Bias shows up.

Press the "OK" key and then use the up/down buttons to adjust the Bias.

When you have what you want then hit the "OK" button to save it and you're done.

That is what I remember. If it doesn't work, don't shoot me. I'm just the messenger.

 

[Diocletian]

Still been fighting with this, been out of town for a while too. New developments:

1. Battery completely discharged over the course of a month, car would just click instead of turn over.

2. Tested battery, it was rated at 11 volts. To eliminate any issues, I replaced the battery and got a battery tender with float control.

3 . After 8 hours of trickle charging the new battery, it was fully charged. Since I still had about 2 gallons of E85 in the tank, I decided to swap to my E85R tune to see if it would start.

4. Car started and ran strong at idle initially, then started sputtering and slowly died. Digital gauge shows 23 miles left on tank. I have a feeling the gas is so old at this point that it's just bad, been in the tank for 4 months

Here's what I want to do:

1. I have a 5 gallon gas can, never used. Fill it with 93 and put that in the car.

2. Swap to 93 tune and try starting it? Or should I try flex first?

Thoughts?
I
honestly owned over 12 cars, new, old, German, Japanese and domestic but God damn I have never had so many issues for a car I barely drive. I should've got the battery tender earlier sure but it's still rediculous all this crap is happening.

 

[Zinc03svt]

I would throw 5 gallons 93 and download flex tune. Start it let it run for 5 minutes. If it is still acting up try to stock tune and see what it does. I have run E35-40ish on stock tune with zero running issues.

 

[MaskedRacerX]

I'm having some of the same issues. FlexTune, '19 GT A10, PP car.

Short version:

- Send logs to tuner
- Tuner sends 93 tune
- Seems to run great, send more logs
- Tuner confirms things are as expected, sends FlexTune
- Car runs strong on E85 Flex, 11.1-11.4 AFRs, but constantly throwing a CEL, specifically a P2097, P2099 (rich condition Bank 1 and 2)
- Car occasionally craps out when cold, like from a stop, throttle, stop again, idles down to a stall
- Have done many Crank Relearns (using an X4, with current firmware)

Then after the car sat for a week, it was doing the exact same thing as the OP, states: chokes down and stops. I manage to kind of finesse the throttle to keep it running, after it was going, it ran fine, drove it 20 minutes, stopped, fired up as expected. Did it again a day later, same thing, kind of gave it throttle by tapping it till it cleared up and stayed running. Then after I drove it, did another crank relearn and now there's no starting issues, it's back to the CEL codes and stalling as described while till it's warmed up good and has been running for like 15 minutes.

So my current situation:

- Car starts fine
- If from a stop, you surge forward, then stop completely, car will idle down to not running, starts right back up
- The above behavior does not seem to be present once it's been running for 15+ minutes

I'm sitting at about 1/2 a tank of Gate E85/Flex (indicated on the pump as 55-83 ethanol). Now my tuner is saying to take it to the dealer, maybe an O2 issue, the car was running perfectly when I bought it at 4K miles, bone stock, mint, it seemed to run fine on the 93 tune, it started the bogging issue after about 7 days of running E.

I think at this point I may:

- Run out the current ethanol in the tank to as empty as I can
- Fill it with 93 octane
- Drive it for a bit, on the FlexTune, then flash back to stock, confirm clean operation, maybe try the 93 tune again

 

[Diocletian]

I'm having some of the same issues. FlexTune, '19 GT A10, PP car.

Short version:

- Send logs to tuner
- Tuner sends 93 tune
- Seems to run great, send more logs
- Tuner confirms things are as expected, sends FlexTune
- Car runs strong on E85 Flex, 11.1-11.4 AFRs, but constantly throwing a CEL, specifically a P2097, P2099 (rich condition Bank 1 and 2)
- Car occasionally craps out when cold, like from a stop, throttle, stop again, idles down to a stall
- Have done many Crank Relearns (using an X4, with current firmware)

Then after the car sat for a week, it was doing the exact same thing as the OP, states: chokes down and stops. I manage to kind of finesse the throttle to keep it running, after it was going, it ran fine, drove it 20 minutes, stopped, fired up as expected. Did it again a day later, same thing, kind of gave it throttle by tapping it till it cleared up and stayed running. Then after I drove it, did another crank relearn and now there's no starting issues, it's back to the CEL codes and stalling as described while till it's warmed up good and has been running for like 15 minutes.

So my current situation:

- Car starts fine
- If from a stop, you surge forward, then stop completely, car will idle down to not running, starts right back up
- The above behavior does not seem to be present once it's been running for 15+ minutes

I'm sitting at about 1/2 a tank of Gate E85/Flex (indicated on the pump as 55-83 ethanol). Now my tuner is saying to take it to the dealer, maybe an O2 issue, the car was running perfectly when I bought it at 4K miles, bone stock, mint, it seemed to run fine on the 93 tune, it started the bogging issue after about 7 days of running E.

I think at this point I may:

- Run out the current ethanol in the tank to as empty as I can
- Fill it with 93 octane
- Drive it for a bit, on the FlexTune, then flash back to stock, confirm clean operation, maybe try the 93 tune again

Yep, I've had basically the same issues since Lund tuning it. They've been helpful but I've cleaned/replaced MAF and tested O2, switched tunes and sent like 20+ logs over the course of a year and we can't pinpoint anything. Car runs fine on 93, which is why I'm trying to get it back to 93 so I can get service done to it and...worst case consider selling it, probably not though.

 

[MaskedRacerX]

Yep, I've had basically the same issues since Lund tuning it. They've been helpful but I've cleaned/replaced MAF and tested O2, switched tunes and sent like 20+ logs over the course of a year and we can't pinpoint anything. Car runs fine on 93, which is why I'm trying to get it back to 93 so I can get service done to it and...worst case consider selling it, probably not though.

Well, I love the car, so I'm definitely keeping it, and honestly, I don't think there's anything wrong, I think it's tune/fuel/some-other-3rd-thing related, especially since mine is basically a new car.

What's the consensus (anyone?), on a Flex with 93 vs. a 93 specific tune? I'm assuming the latter.

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