I did some datalogging today and noticed my LTFT is really high, ranging between 8 - 18%. Im running a Trifecta tune along with a AEM cold air intake and a ZZP catted downpipe.

Also noticed that my AFR is really high (runs lean), which seems to be atypical of a Trifecta tune.

How bad is this for the health of my engine? Is there any way to correct this without retuning?

Thanks for any help.

 

If you still have stock intake you could slap that back on and see if it's better.

 

This Trifecta tune is tailored for an AEM cai, supposedly. I do not have the stock intake.

I did more research and supposedly there could be a vacuum leak? Anybody care to post a vacuum diagram?

Thanks

 

trifecta tune will usually get u +7ish fuel trims, +18 is high even for them. just do a boost leak test, I probably have a boost leak. if ur trims are around 10 or over at idle u most definitely have a boost leak

 

when i was on trifecta my fuel trims were within -/+5 with the k&n intake, trifecta usually runs rich no lean, did you get the canned budget tune? either way trifecta isnt what they used to be which is why i switched to hptuners

 

trifecta ran rich with the a/f ratio. but they were always lean with the trims. the ecp tune was always pretty rich though with the trims. my trims, and I asked vince to get them better, but he said they were good. were +7 with the normal tune and -7 with the ecp tune on the k04. not even gonna get started on their attempt to tune the zfr with my bigger injectors

 

As far as I know, this is a tailor made tune (the previous owner of the car bought the tune, not me).

I logged the AFR and it seems to run lean most of the time as well, rarely dipping below 14.7, even under boost.

How bad will it be if I keep driving the car? I prefer Trifecta for the select-a-tune feature which is useful for my long commute to work.

I sent WOT Tuning an email, hopefully they'll have things sorted monday.

 

If you're staying out of boost it doesn't really matter what tune is running.

 

Roughly 14.7 is where you should to be when you're cruising, even up to around 10psi. Shoot, when the car enters DFCO you'll see upwards of 20:1afr. The only time you'll go much richer is under hard acceleration and WOT. If you start seeing 14.7 under those conditions, then you'll have to worry. Maybe I take this stuff for granted, but I though this was pretty common knowledge for most car modding enthusiasts.

As far as your trims go. Either the tune needs to be dialed in much better or you have an issue.

 

Sorry, I wasn't clear. I meant that my AFRs were hovering around 14.7 even at WOT, which as you've mentioned is disconcerting.

Will a boost leak cause a lean condition? I figured that it would actually do the opposite and make the engine run rich, as the engine will be receiving less air than what was metered.

 

Yikes that's lean at wot.get that fixed asap. Don't go wot till u do. Hp tune it. I loved the select a tune as well, trust me a good hp tune and Ull forget about it

 

Yikes. If you're seeing 14.7 during WOT pulls, that's a big time no no. Get ahold of your tuner asap and get that fixed.

 

Trying to get a hold of SSKev at the moment. He's the only one around here.

I guess the risk of running stoic at WOT is melted pistons right? I am not getting any KR fortunately.

 

Before I get retuned, are there basic diagnostic measures I should take to rule out trivial issues?

I plan on cleaning the MAF to see if that will help.

 

Some good tips here...


https://www.cobaltss.net/forums/tuni...k-list-298303/

 

Recently I reset my battery and my LTFT stays around 0 during idle. The LTFT rises to +7 after driving around, and seems to stick there more or less.

Just noticed that my AFR's do in fact go down to about 12.X while at WOT. But during cruise and mild boost regimes, I'm seeing high 14's to low 15's.

The car seems to drive excellent, and makes enough torque that the clutch will slip in 5th going about 100 km/h and WOT.

I don't feel like paying for a retune in the mean time. What kind of problems will I experience if I ignore this?

 

This makes me cringe, don't do that, down shift to 4th. Also a stock LNF would probably slip the clutch doing that.

 

LTFT is a calculated number. What are you STFT's like at idle/crusing?

And as stated there is really never any reason to go WOT in 5th. You will break something eventually

 

I don't know anything about Trifecta, but I know in HPT you can do a MAF calibration to help fix both LTFT and STFT's.

 

He needs to shift to 3rd, not 4th

 

Disconnect your EVAP and then it will only be STFT and you don't have to worry about a LTFT messing with your WOT fueling. Def log the change if you still have the trifecta cable.

 

Never a reason to go WOT in 5th my friend. Unless you're trying to hit 260km/h.

 

Not saying you're wrong, but do you mind explaining the science behind this?



Also, thank you everyone for the heads up about going WOT in 5th. I come from low powered cars and do it all the time without consequence. It makes plenty of sense though.

 

When you disconnect the EVAP solenoid if locks the LTFT at 0.0, then the only adjustments are made with the STFT based off the wideband. Most of the time the LNF likes it better disconnected, also the LTFT is global for the e69 which is not that good of an idea and still unsure of why they selected this since the LSJ (iirc P12) ecu has 12 different LTFT depending on load and RPM

 

ok, but then that is just a pseudo-fix. The fact that my motor is running lean remains.

I'm not having any driveability issues, but I'll disconnect it to see how things go. My evap can't pass emissions for **** anyways, lol