FN2 won't work with any MAF calibration (running extremely lean)

FlashPro questions & answers specific to the FN2 European Civic Type R
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rattinger
Posts: 4
Joined: Thu Sep 11, 2014 11:46 am

FN2 won't work with any MAF calibration (running extremely lean)

Post by rattinger »

Hello!

Here is the problem:

Car is 2010 CW Civic Type R with following modifications:
- custom made 4-2-1 header
- 2.5" exhaust with no cat (secondary O2 sensor removed also)
- RRC intake with stock air box K&N installed

Car was tuned with MAP Calibration on dyno making ~225 hp.

Car worked pretty fine, but fuel consumption was quite high and it didn't work very fine on part throttle (thoughts based on "Ass-dyno" and engine sounds).

Problem is: now i'm trying to return to MAF-calibrations (which should be used instead of map-calibrations), but car won't work at all with any MAF-calibration.

Right after start S.term starts to rise until reaches 47% and A/F goes up to 18-20 ! In other words, car is running very very lean.

If I touch to throttle pedal, car dies immediately.

I have already tried new stock wideband O2-sensor, new MAF-sensor and many different MAF-baset calibrations, including N Group Reflash.

I think that it can't be air leak, because it works with MAP-calibrations?

I haven't yet tried to unlock ECU and returning it to stock.

Also if it would matter, I also mention that tried once also Asian version FD2 map (made fault codes)

(sorry for bad language, hope you understand :)
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Spunkster
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Posts: 19364
Joined: Fri Sep 20, 2002 5:06 pm
Location: Hondata

Re: FN2 won't work with any MAF calibration (running extremely lean)

Post by Spunkster »

Try returning the ECU to stock, but do not unlock it and see if it will run with that.
rattinger
Posts: 4
Joined: Thu Sep 11, 2014 11:46 am

Re: FN2 won't work with any MAF calibration (running extremely lean)

Post by rattinger »

Thanks for reply

I've already tried that
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Spunkster
Site Admin
Posts: 19364
Joined: Fri Sep 20, 2002 5:06 pm
Location: Hondata

Re: FN2 won't work with any MAF calibration (running extremely lean)

Post by Spunkster »

If it does not run with the return to stock then there is some issue with the vehicle that needs to be addressed.
rattinger
Posts: 4
Joined: Thu Sep 11, 2014 11:46 am

Re: FN2 won't work with any MAF calibration (running extremely lean)

Post by rattinger »

When using MAF-calibrations I get following values on idle:

Cold engine:
RPM 1300rpm
MAP 410 mBar
AFM.v 1,33 V
AFM 4,3 g/s
AFC.c 100 mg
S.Trim 47%
A/F 19,20

Even when engine not running AFM values are:
AFM.v 0,76 - 0,84
AFM 0,57 - 0,82 g/s
AFM.c 0 mg

Are those values correct?
rattinger
Posts: 4
Joined: Thu Sep 11, 2014 11:46 am

Re: FN2 won't work with any MAF calibration (running extremely lean)

Post by rattinger »

Any advice? Anybody?
curtusz
Posts: 206
Joined: Sat Jun 01, 2013 10:14 am
Location: Wakefield/Leeds uk

Re: FN2 won't work with any MAF calibration (running extremely lean)

Post by curtusz »

Wow 19.. that is lean .. I've always used target lambda .. never had an issue .. I'm on 2011 euro fn2 .only time I hit 19 is on deceleration (fuel cut) .. all I could say is try a factory or n group map .. see if that resolves it .. dont really see the point of fine tuning fuel unless your boosted. Let the ecu do the work for you .. also check your mani and flanges for cracks/holes
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