Another STFT question. Please Help!

Update: checked the o ring on the MAF and it looked to be ok. Tried cleaning the MAF as well and no luck had to cancel my appointment at the dealership due to having to work late as well. Stand still.

Turns out the fuel injectors are bad. Going to cost around 1500 to fix lol

Civic17siYAY said:

Turns out the fuel injectors are bad. Going to cost around 1500 to fix lol

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How did you figure this out?

Civic17siYAY said:

Turns out the fuel injectors are bad. Going to cost around 1500 to fix lol

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Not covered under warranty??

hobby-man said:

Not covered under warranty??

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Nope warranty expired at 36k miles. Funny, their "lifetime warranty" doesnt cover injectors..

raynist said:

How did you figure this out?

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3 trips to the dealership to figure it out.

raynist said:

How did you figure this out?

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I was wondering how the Dealer determined it was the Fuel Injectors, and not the Flux capacitor ??
Maybe they make more profit changing 4 Fuel Injectors that they claim are not under warranty, than one fictitious Flux capacitor.

Note: Dealers will often say that fuel injectors are not covered, because they will say you were not using Premium Fuel. If you were, Helps if you keep your gas purchase receipts, so you can prove them wrong.
I would also find some way to mark your current injectors (maybe with UV dye), and insist you get your old Injectors returned to you.
Then you can make sure what they give you back are YOUR injectors, and if they look ok, maybe get them tested, just to make sure.
However, maybe if your car runs OK after the injector change, maybe it was the injectors.

Personally, I would consider running few tanks of gas with Injector cleaning added, to see if that helps.

$1500 for new injectors after 60K miles.
60K miles on Premium fuel over regular = about $850 extra in fuel, that may not have cause your injectors to clog, or at least would defeat the "You should have used Premium Fuel" argument.

Also, if the Dealer is not going to cover the Injectors under warranty, why pay the premium price to have the Dealer replace the Injectors ?

My was also -8 ltft and -15 stft stock. Called dealer and they did say that if it is within the limits it is ok. If the limit will be crossed you will get a warning msg.

Because of this, I did calibrate maf myself. Now I have ltft +- 1 average stft -+ 5.
Correction was progressive 8-9% at 700 to 1-2% at 4000 and 0 at 7000

My 2 cents if I have problem with injectors (clogged) than I would see higher correction at higher LOAD/RPM.

For vacuum leak: you would need to go over everything after MAF sensor. So turbo intake, charge pipe, intercooler, to throttle body.

Miha__ said:

My was also -8 ltft and -15 stft stock. Called dealer and they did say that if it is within the limits it is ok. If the limit will be crossed you will get a warning msg.

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Wait a second... the dealer said our cars have a message pop up for bad fuel trims? Interesting.

gtman said:

Wait a second... the dealer said our cars have a message pop up for bad fuel trims? Interesting.

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Yep, a CEL with code p0170 fuel system to rich or lean

Any idea how bad they need to be for the code to pop?

fenix-silver said:

Any idea how bad they need to be for the code to pop?

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15-20%

Mine would pop up around 18. Stft were constantly pegged out at light load and idle -25. It's been running fine ever since. As far as paying the premium for getting them done at the dealership, I dont have time to shop around to see who would give me the best deal. I drive a ton for work and needed to get it done asap. Plus they gave me a free loaner for the week that it was in the shop. All said in done, I put the equivalent of 4 years or so of miles on my car in 10 months.

They didnt say why they went bad, if they mentioned the no premium argument I would have shown them my receipts. I think I just got a car with junk injectors or maybe got bad gas somewhere. Who knows

Miha__ said:

My was also -8 ltft and -15 stft stock. Called dealer and they did say that if it is within the limits it is ok. If the limit will be crossed you will get a warning msg.

Because of this, I did calibrate maf myself. Now I have ltft +- 1 average stft -+ 5.
Correction was progressive 8-9% at 700 to 1-2% at 4000 and 0 at 7000

My 2 cents if I have problem with injectors (clogged) than I would see higher correction at higher LOAD/RPM.

For vacuum leak: you would need to go over everything after MAF sensor. So turbo intake, charge pipe, intercooler, to throttle body.

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Are you using stock intake?
My also stock intake and just recently i flash the "return to stock" and unlock hondata from vehicle.
WIth the car now stock, i continue monitor hondata basic parameter just to find out that my STFT have high negative value at idle. -12% to -17% at idle, -3% to -6% at partial throttle acceleration, 0% at WOT.
However my LTFT also at -100%. I read somewhere that LTFT is not being use in this platform ECU outside of USA.

I'm not sure is this normal for a stock intake and stock map. Any input about this high negative fuel trim is much appreciated.

I also upload datalog for referrence.

Yes, I'm using stock intake

Outside USA, computer uses STFT and LTFT till MAF voltage is 4.1 at that it switches to fuel strat 2.
This means it uses open loop. So, it goes directly from MAF curve values.
Till voltage 4.1 LTFT and LTFT play a role after not.

Hence different strategy of calibration has to be used.
Before you try to reduce LTFT to a range +-2.
For open loop you need to look AFR, AFR adj and AFR cmd.

The only good software for doing this was from Vit viper (unfortunately I do not have it)
Your log should be kdlg or dlg format so that my ktuner can read it.