Can hot weather and high humility cause high negative long term fuel trim ?

[Alex_hockey69]

Iv been running +6psi set up and my long term fuel trims are over -10 is this normal ?
Here in Montreal Canada it's around 30 degree Celsius with a lot of humility does this cause the fuel trims to be like this ? In the winter long term trims would be +1 - -1 long term. I have the factory Intake on . I used the K&N Red Typhoon short Air Intake System and was getting the same fuel trims in summer and winter. Even calibrating my MAF for months going though this problem I guess I could say it would not change, I am guessing it is because of the hot weather here. I am planning on putting back the K&N air intake on because I love the sound that comes from it and if I am getting the same fuel trims why should I brake my head trying to rescale my MAF again when it changes nothing with my fuel trims. No matter what I try stock air filter or the k&n my long term will always be high negatives.

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[gtman]

I live in a warm, humid area as well. My car definitely runs richer than in the colder weather.

Remember, cold air is oxygen dense; with heat and humidity, much less so.

 

[JT Si]

I live in a warm, humid area as well. My summer fuel trims definitely run richer than in the colder weather.

Oddly enough on TSP stage 1 my fuel trims have been slightly positive in winter and spring.

Once summer hit and it's been 80-95F and humid, they are nearly perfectly 0 all the time.

 

[Alex_hockey69]

data log with stock intake and running +6psi FTS

 

[gtman]

Oddly enough on TSP stage 1 my fuel trims have been slightly positive in winter and spring.

Once summer hit and it's been 80-95F and humid, they are nearly perfectly 0 all the time.

Actually that makes sense. Running slightly lean in cold weather and then a little richer in warm weather as I was saying. Same exact scenario with my car on TSP 1 (non-Si).

I also wonder if winter blend versus summer blend gas is part of the equation.

 

[Alex_hockey69]

i did this data log today and my long term fuel tims went as high as -16

 

[fenix-silver]

i did this data log today and my long term fuel tims went as high as -16

That sounds a bit worrying to me. Last summer w/ the stock intake, the worst I'd see during the hottest weather was around -8.

 

[Alex_hockey69]

I will return to stock and drive for a few days and see what happens, maybe it's the tune the problem. Hondata told me it's a problem with AFM reading. The car has 40000km only

 

[Masked]

On TSP Stage 1 I usually run a bit richer during summer when its hot and humid here in Quebec, but I usually don't see anything above -4 or -5 LTFT. -16 is worrying

 

[Alex_hockey69]

On TSP Stage 1 I usually run a bit richer during summer when its hot and humid here in Quebec, but I usually don't see anything above -4 or -5 LTFT. -16 is worrying

I am in Montreal QC so I should be the same as you .. you have the stock intake?
Ktuned or hondata with your TPS stage 1

 

[Hollywoo0220]

Iv been running +6psi set up and my long term fuel trims are over -10 is this normal ?
Here in Montreal Canada it's around 30 degree Celsius with a lot of humility does this cause the fuel trims to be like this ? In the winter long term trims would be +1 - -1 long term. I have the factory Intake on . I used the K&N Red Typhoon short Air Intake System and was getting the same fuel trims in summer and winter. Even calibrating my MAF for months going though this problem I guess I could say it would not change, I am guessing it is because of the hot weather here. I am planning on putting back the K&N air intake on because I love the sound that comes from it and if I am getting the same fuel trims why should I brake my head trying to rescale my MAF again when it changes nothing with my fuel trims. No matter what I try stock air filter or the k&n my long term will always be high negatives.

A few have replied with their Fuel Trims, however they are on different tuning platforms & locations.

Basically (with regard to High Ambient Temps & Humdity), it increases the heat capacity of the charge. That results in lower compression and combustion temperatures. This delays the auto-ignition event and lowers the rate of heat release and lengthening combustion duration. So, if the ECU does not modify the fuel delivery duration you would run really rich and/or have detonation that would kill ya....

Hope that helps.
You don't have issues, the vehicle dynamics are taking care of what they should.

 

[Alex_hockey69]

A few have replied with their Fuel Trims, however they are on different tuning platforms & locations.

Basically (with regard to High Ambient Temps & Humdity), it increases the heat capacity of the charge. That results in lower compression and combustion temperatures. This delays the auto-ignition event and lowers the rate of heat release and lengthening combustion duration. So, if the ECU does not modify the fuel delivery duration you would run really rich and/or have detonation that would kill ya....

Hope that helps.
You don't have issues, the vehicle dynamics are taking care of what they should.

I still have worries I mean -16 long term is pretty high. I am curious too see what the car does stock without a tune. Which I will do later today

 

[Hollywoo0220]

I still have worries I mean -16 long term is pretty high. I am curious too see what the car does stock without a tune. Which I will do later today

You may be experiencing a bit of blockage on the injector(s).
If you have messed with anything that affects AFR (like the MAF), that could also be a culprit.
Hard to determine.
You can always use a highly reputable Fuel Injector cleaner and monitor the difference over that test duration? If no change, you can always inspect the Injectors (get NEW Seal kit!) and inspect and possibly clean-up or follow up on the AFR or BOTH.

Do BOTH STFT & LTFT adjust when you mash the pedal? or just the STFT and the LTFT remains a constant?

 

[Hollywoo0220]

@Alex_hockey69
If you do have the STOCK air box in / Take off the TOP portion and inspect the RESONATOR and see if that is broken. I have heard that those can affect things. Also, have you used a MAF spray to clean off the sensor?
These are a few addt'l things to consider that take very little time.

 

[Masked]

I am in Montreal QC so I should be the same as you .. you have the stock intake?
Ktuned or hondata with your TPS stage 1

I have the PRL Short ram with the street maf and tsp stage 1 with Ktuner

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