FK8 misfiring?

FK2 Civic Type R 2015-2017, FK8 Civic Type R 2017-2021, FL5 Civic Type R 2023+ and Integra Type S 2024+
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leechihfei
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FK8 misfiring?

Post by leechihfei »

Hi Hondata,

I have been feeling what seems to be mis-firing issues.
My FK8 is a 2018, with G25-660 turbo, PRL downpipe, Cat back exhaust, PRL intercooler, Radiator upgrade, Hondata Fuel upgrade, etc.

After tuning and running around is fine. But I noticed mis-firing occasionally, around 5500rpm especially on a hot day (32 deg C) on track. Changed the plugs, to no avail. Looked at the data log, can't quite make sense of it.

Mis-firing, meaning like it feels like a power cut, unable to generate bhp, burbles from exhaust.

Attached datalog for your kind assistance and analysis.
Attachments
datalog0018.fpdl
(1.17 MiB) Downloaded 103 times
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Hondata
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Re: FK8 misfiring?

Post by Hondata »

Your fuel trims are high, but the problem is that the fuel system is losing fuel pressure over 5000 rpm.
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leechihfei
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Re: FK8 misfiring?

Post by leechihfei »

If I've already have Hondata Fuel upgrade, and I'm losing fuel pressure, what could be the problem?

1. Fuel filter?
2. As everything else is supplied by Hondata Fuel Upgrade System. Did I miss any other possible (culprit) part?
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Spunkster
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Re: FK8 misfiring?

Post by Spunkster »

Have you checked the fuel system for contamination?

Please see: https://www.civicx.com/forum/threads/us ... ion.65283/
leechihfei
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Re: FK8 misfiring?

Post by leechihfei »

No I haven't. I'm not on flex fuel.
Regardless, will revert upon doing so.
leechihfei
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Re: FK8 misfiring?

Post by leechihfei »

Hi,
Since your suggestion to check the fuel filter, I had it changed.
Did notice that there were some contaminants - but not surprising since my car has pushed past 30,000 miles already.

Change to a new fuel filter and a new low pressure fuel pump.
Re-tuned the car with 4Pistons cams on a dyno. It was great. On the Dyno, it was fine, 20 out of 20 pulls.
_________________________________________________________

BUT after driving for about 1000 miles, and 100 miles that day, the same backfire problem started again. Log attached.
I must stress the problem is intermittent - 5 out of 10 pulls on the road, I get the backfire. But it can be replicated when I get it.

a. Could the Hondata Hi Pressure Fuel Pump be acting up?
b. Heat? (Ambient was about 90 degF)
Attachments
160823 CamRefined 95Oct.fpcal
(17.82 KiB) Downloaded 56 times
datalog10 160823 Backfire2.fpdl
(31.6 KiB) Downloaded 69 times
datalog9 160823 Backfire1.fpdl
(40.11 KiB) Downloaded 60 times
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Spunkster
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Re: FK8 misfiring?

Post by Spunkster »

It looks like the fuel system is maxing out. You may need to try lowering the air charge to make less boost so that it does not max out.
leechihfei
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Re: FK8 misfiring?

Post by leechihfei »

1. When I look at the datalog. I notice that the Fuel Pressure dropping first, BEFORE the Fuel Pump Duty Cycle hits 100%.
Doesn't this indicate the High Pressure Fuel Pump is having a problem?

2. And AirC is at 224% Is that even high?

3. Also, the backfire doesn't happen all the time. I have some logs that allows a clean pull, using the same calibrations.
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Re: FK8 misfiring?

Post by Spunkster »

What is your fuel system serial number?
leechihfei
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Re: FK8 misfiring?

Post by leechihfei »

My fuel system serial number is 1034.
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Re: FK8 misfiring?

Post by Spunkster »

Send an email to support <at> hondata.com with the following and I will issue an RMA and give you further
instructions:

Name:
Address:
Phone:
Email:
Serial#:
Description of problem:

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