Missfire Repeating

[ULWizSS]

So i friend from my forum asked me to take a log to see what was going on. He thought it was running rich. At WOT it commanded 11.8.

He decided to go home after it was running good to change his plugs out. After he did this he said the car was running like crap. Believe the are NGK gapped at .040 I went down to his house today and for some reason cyl 2 & 3would just missfire to 100 and do it over and over again. Should he have a compression test and leak test done.

Sitting at idle he is commanding 10.1 afr?

http://www.youtube.com/watch?v=pV4YJ...layer_embedded

[BackyardTurbo_FTW]

no fuel trims?

[ULWizSS]

LTFT & STFT is that what your looking at?

[skatinboarding]

.040 is a big gap. Iirc mine are gapped at .033.

[ULWizSS]

.040 is a big gap. Iirc mine are gapped at .033.

Been trying to get him to regap at .035

[Iam Broke]

A tight .032 works best for me.

[Jaxon]

My 3787s are gapped at .030.

[ULWizSS]

Fuel trims are causing this according to zzp. They sent me two updated tunes today which did not fix the problem yet. So the ECU is going back to ZZP at this point.

[Leafy]

Why not tune it with hp tuners? You are on the hp tuners forum.

[ULWizSS]

I am not a experienced tuner and was just doing a forum member a favor by looking at this tune and taking a log of it. Was not getting paid for any of this. Other than that i would not know where to start when fixing his issue.

I was more there for taking a log of the car. ZZP does not understand why the fuel trims are not working either. They sent me two updated tune and still the same results.


If the kid had 200 to 300 i would just send him to Nick at BYT for a fix.

[Leafy]

If the fuel trims are reading 0 then for some reason the car isnt entering closed loop. either the table isn't set up right, the engine temp sensor is fucked (would show cold all the time on the dash and in hp tuners), or the narrow band o2 sensor if fucked and the computer is reading it as an error, locking itself out of closed loop, but not throwing a code for some weird reason.

[BackyardTurbo_FTW]

Everything looked right when I checked quick but it def was showing 0 and 0 for the trims the whole log, which isnt right.

[roadconetuning]

log 02 voltage and see what its showing...

[BackyardTurbo_FTW]

You can see the Mv in the log, its 900's (rich as shit)

[roadconetuning]

isnt that the failure mode of narrowbands?

[BackyardTurbo_FTW]

On the Subaru's it will shows 14.7 and NEVER fluctuate at all when it dies. Not sure if these cars do the same.

[roadconetuning]

nvm, im thinking backwards... it should show lean if it failed... as a fail safe to make it go rich.