Lund flex fuel tune on 93 high alch_pct

[Jay-rod427]

Mine was showing 19.4%, filled up last night and it instantly went goofy. Shot up to 26%, then quickly came down to about 14%, then finalized and flagged that learning was complete at 18.2%. Not sure what's going on it used to slowly and predictably move to where it would end up before settling and completing the learning. Still runs strong as ever, and fuel trims are spot on so:shrug:

Sure would be nice if someone from Lund would occasionally jump on here and help out some of these tune related questions...

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[LG23]

For anybody reading, I got my solution. Hopefully this helps some of you who have the same issue.

The car had no vacuum leak, only other thing installed was a CAI and an oil separator with zero install error. Also definitely not going to be the gas, no way because I filled up at multiple stations and I can see it reading 20% highest MAYBE but definitely not 30% or more.

Jon jr@lund suggested it might be a vacuum leak, less chance it was the gas. He gave me a non FLEX tune to do logs and to see what was going on. A few non-flex tune revisions later, he gave me the revised flex-fuel version. The car learned it at 9.8% consistently, there wasn't any jumping up to anything above 10.5 at all. Also, I drove until 10 miles were left in the tank and filled up at another station with 93 and then drove 45 miles. It is still learned at 9.8%. AFR is 13.8-14.2 at idle/part throttle and around 11.8 at WOT.

Jon was very responsive and got back to me very quickly each time I sent the logs. He was snapping revisions back within hours and we got it all done in 2 days or so.

TLDR: It was the tune.

 

[DarkestHour]

For anybody reading, I got my solution. Hopefully this helps some of you who have the same issue.

The car had no vacuum leak, only other thing installed was a CAI and an oil separator with zero install error. Also definitely not going to be the gas, no way because I filled up at multiple stations and I can see it reading 20% highest MAYBE but definitely not 30% or more.

Jon jr@lund suggested it might be a vacuum leak, less chance it was the gas. He gave me a non FLEX tune to do logs and to see what was going on. A few non-flex tune revisions later, he gave me the revised flex-fuel version. The car learned it at 9.8% consistently, there wasn't any jumping up to anything above 10.5 at all. Also, I drove until 10 miles were left in the tank and filled up at another station with 93 and then drove 45 miles. It is still learned at 9.8%. AFR is 13.8-14.2 at idle/part throttle and around 11.8 at WOT.

Jon was very responsive and got back to me very quickly each time I sent the logs. He was snapping revisions back within hours and we got it all done in 2 days or so.

TLDR: It was the tune.

Damn. I'll have to open another ticket and ask for the LG23 secret sauce.

 

[LG23]

Damn. I'll have to open another ticket and ask for the LG23 secret sauce.

A wise man once said "If a man does not have the sauce, then he is lost. But the same man can be lost in the sauce." -Gucci Mane 1865


Make the email out to Jon jr and say Lazar sent you :cheers: I emailed him earlier today and mentioned I have a buddy with the same issue.

 

[DarkestHour]

A wise man once said "If a man does not have the sauce, then he is lost. But the same man can be lost in the sauce." -Gucci Mane 1865


Make the email out to Jon jr and say Lazar sent you :cheers: I emailed him earlier today and mentioned I have a buddy with the same issue.

Thanks, will see what he says. They're probably getting tired of me. I typically tune my cars myself but for the Mustang I figured it'd be easier in regards to my time to just have someone much more experienced handle it.

 

[Redmoe]

I sent in a ticket as well. Hopefully they will get back soon. Thanks for the heads up.

 

[Jay-rod427]

Don't know if its a coincidence or not, but this weekend I reinstalled the stock intake and loaded a different tune revision (was revised for transmission only changes) to force the alcohol learn to start over. Came out perfect 12.2% on the same exact tank of fuel that previously read 18.2%. I have also noticed when a false alcohol % is read it jacks with the fuel trims.

 

[Sasuketr]

For anybody reading, I got my solution. Hopefully this helps some of you who have the same issue.

The car had no vacuum leak, only other thing installed was a CAI and an oil separator with zero install error. Also definitely not going to be the gas, no way because I filled up at multiple stations and I can see it reading 20% highest MAYBE but definitely not 30% or more.

Jon jr@lund suggested it might be a vacuum leak, less chance it was the gas. He gave me a non FLEX tune to do logs and to see what was going on. A few non-flex tune revisions later, he gave me the revised flex-fuel version. The car learned it at 9.8% consistently, there wasn't any jumping up to anything above 10.5 at all. Also, I drove until 10 miles were left in the tank and filled up at another station with 93 and then drove 45 miles. It is still learned at 9.8%. AFR is 13.8-14.2 at idle/part throttle and around 11.8 at WOT.

Jon was very responsive and got back to me very quickly each time I sent the logs. He was snapping revisions back within hours and we got it all done in 2 days or so.

TLDR: It was the tune.

I had a similar problem with the gas being bad. Instead of my regular station i used a different one but same brand, and my AFR all of a sudden went down from 14.2 to 13.4 13.5 range. I knew what was going on, that station had more ethanol mixture in the fuel. It is kinda annoying to wait for the flex fuel logic to do relearn but thats normal. I kinda want to get a separate 93 octane tune from Lund as well to compare but I don't know if its worth it.

 

[LG23]

I sent in a ticket as well. Hopefully they will get back soon. Thanks for the heads up.

No worries, its what this site is for :cheers:

I had a similar problem with the gas being bad. Instead of my regular station i used a different one but same brand, and my AFR all of a sudden went down from 14.2 to 13.4 13.5 range. I knew what was going on, that station had more ethanol mixture in the fuel. It is kinda annoying to wait for the flex fuel logic to do relearn but thats normal. I kinda want to get a separate 93 octane tune from Lund as well to compare but I don't know if its worth it.

Mine also did fluctuate maybe 6% lower tops at a different station using 93. There is just almost no way pump fuel is almost 30%. Even 15-25% is rare. I confirmed this because with the same exact pump gas after Jon fixed the MAF curve it went from 34% all the way down to 9.8%. Then I went to another station 40 miles further the next day with 10 miles to empty and filled with 93 again. It stayed at 9.8% and didn't fluctuate whatsoever above 10%.

I was skeptical to begin with using an off the shelf tune without revising the MAF curve. If it is closer to 20% or higher I definitely would not assume it is just the fuel, it's very unlikely.

I asked what was changed to the tune for the 3 revisions and this was the response:

"And I just massaged the MAF curve so it was closer so that the FLEX logic could learn more accurately. In order for the FLEX to be accurate injector data and MAF data has to be very very close. It's not that it was way off before, it just wasn't close enough for the Flex logic to learn an accurate %. That is one of the downfalls of Ford's OE flex logic since it depends on the fuel correction to calculate the % vs using a sensor like GM's do."

I was also on the verge of just asking for a 93 oct tune and to just refund all the extra I paid for flexfuel but Jon Jr was VERY responsive and was able to fix it very quickly

 

[Redmoe]

Working with them now. Doesn't seem like they think the percentage being that far off is a problem. Mentioned that others folks have had this resolved but it seems I may have to push a little harder to get them to look at it. Getting my original 91 tune converted to the ngauge as a back up option.

 

[Jay-rod427]

No worries, its what this site is for :cheers:



Mine also did fluctuate maybe 6% lower tops at a different station using 93. There is just almost no way pump fuel is almost 30%. Even 15-25% is rare. I confirmed this because with the same exact pump gas after Jon fixed the MAF curve it went from 34% all the way down to 9.8%. Then I went to another station 40 miles further the next day with 10 miles to empty and filled with 93 again. It stayed at 9.8% and didn't fluctuate whatsoever above 10%.

I was skeptical to begin with using an off the shelf tune without revising the MAF curve. If it is closer to 20% or higher I definitely would not assume it is just the fuel, it's very unlikely.

I asked what was changed to the tune for the 3 revisions and this was the response:

"And I just massaged the MAF curve so it was closer so that the FLEX logic could learn more accurately. In order for the FLEX to be accurate injector data and MAF data has to be very very close. It's not that it was way off before, it just wasn't close enough for the Flex logic to learn an accurate %. That is one of the downfalls of Ford's OE flex logic since it depends on the fuel correction to calculate the % vs using a sensor like GM's do."

I was also on the verge of just asking for a 93 oct tune and to just refund all the extra I paid for flexfuel but Jon Jr was VERY responsive and was able to fix it very quickly

I believe 9.8% is the baseline. That's why you showed exactly 9.8% both different tanks, likely because it is actually less than that from those stations, but that's as low as it goes on the scale, just like it maxes at like 76% or something like that. That's as far as the stock parameters are built in.

Could be wrong.:shrug:

Got a ticket with Lund right now looking at mine, but they are looking into my new intake being the culprit of the MAF being not quite as accurate as they'd like for the flex fuel logic.

 

[LG23]

Working with them now. Doesn't seem like they think the percentage being that far off is a problem. Mentioned that others folks have had this resolved but it seems I may have to push a little harder to get them to look at it. Getting my original 91 tune converted to the ngauge as a back up option.

At first they were telling me it didn't really matter and it's fine. But just looking at AFR showing so rich why would I want it to run like that thinking the fuel is 30% when it's not, ya know?

I guess I was annoying enough and they finally decided to look into it deeply and actually massage the MAF curve into place through 3 revisions. I paid extra for the flex fuel tune so they better bet I'm going to expect it to work correctly with the MAF the free revisions were a big selling point to me as well.

I believe 9.8% is the baseline. That's why you showed exactly 9.8% both different tanks, likely because it is actually less than that from those stations, but that's as low as it goes on the scale, just like it maxes at like 76% or something like that. That's as far as the stock parameters are built in.

Could be wrong.:shrug:

Got a ticket with Lund right now looking at mine, but they are looking into my new intake being the culprit of the MAF being not quite as accurate as they'd like for the flex fuel logic.

Interesting. It makes sense. It jumped to maybe 10.5 tops but learned at 9.8 and never showed lower so you're probably right.

Jon@lund fixed it up real quick so I'm sure they'll take care of you as well. He was actually sending me revisions to log faster than I could even find the time to log.

 

[CeleronXXX]

This happened to me when I went with the gt350 air intake. After blaming me initially and saying I had to have a vacuum leak they eventually looked into it further and found the maf signal needed to be adjusted. I just switched to the jlt 350 air intake and the same thing happened. This time they skipped the blaming and just went straight to correcting the maf curve again. They've been quick about revisions. I have found with them if you don't read your own logs and point things out they will just say everything looks good. When I send revisions now they know I've already carefully read the data log so they are good about it and make changes.Car runs awesome.

 

[Slow.0]

Do you guys see a big difference between the 93 oct tune and the flex fuel tune? (Assuming someone has had both tunes)

 

[LG23]

This happened to me when I went with the gt350 air intake. After blaming me initially and saying I had to have a vacuum leak they eventually looked into it further and found the maf signal needed to be adjusted. I just switched to the jlt 350 air intake and the same thing happened. This time they skipped the blaming and just went straight to correcting the maf curve again. They've been quick about revisions. I have found with them if you don't read your own logs and point things out they will just say everything looks good. When I send revisions now they know I've already carefully read the data log so they are good about it and make changes.Car runs awesome.

Agreed. They are quick about revisions but if you don't look at the logs yourself and specifically point something out or specifically ask for the MAF curve to be corrected they will leave it as is and say it is fine. Unless lambda isn't at the target numbers or something.

Do you guys see a big difference between the 93 oct tune and the flex fuel tune? (Assuming someone has had both tunes)

When done correctly they will work the same, the only difference being with flex fuel you can use any fuel on the fly and it adjusts based on the alchohol percentage. For example you can fill up half of your tank with 93 and he other half with e85, it will adjust and provide more power the more alchohol% that there is in the tank.

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