P0171 and P117B after Edelbrock SC FIXED

[steve99]

Originally Posted by Irace86.2.0

I think I figured something out. I did an idle log. I have never done one. I did it just to see what my MAP at idle shows to compare to yours, and it shows 0.32 bar, which is 0.68 bar below atmospheric or 9.86 psi of vacuum, but my gauge showed roughly 20 psi of vacuum. See the log below where I tried to replicate your startup logs, which was a warm start--not a cold start (this is a custom tune on E85, just FYI):

https://datazap.me/u/jirace/test-com...0&data=8-25-29

Honestly, I am not a tuner, so I am lost on why the log doesn't show more vacuum. My gauge is accurate. I know ECUTEK has limits on boost (or at least 19 psi was all it could log), but I don't know if it has limits on low MAP values too or what. In short, maybe the MAP is fine on your logs.

I'm honestly kind of lost. We can't compare fuel tables because of my 770cc port injectors and E85.

Going back to your trouble codes, it said the direct injectors in bank 1 were faulty and you got a lean condition. I don't know if one of your direct injectors failed causing a lean situation, or if your direct injector seals failed, but the latter could introduce unmetered air under piston expansion and could result in a poor idle because of compression loss. Outside of that and a bad o2 sensor or crack in your manifold, I just don't know man. I need to hand this one over to someone more knowledgeable.

@tomm.brz
@steve99

What is normal guys? Should his atmospheric pressure be 1.0 if he is at 5000 feet. Mine is 1.01 and stays there. My MAP starts at 1.01 and goes down. His starts at 0.88 and goes down, but his atmospheric pressure says 1.0. Why doesn't our logs indicate more vacuum at idle? My gauge says 20 psi of vacuum, but my idle log says like 9 psi. I know the gauge is accurate.

raw manifold pressure should be aprox 1 bar with ignition on but engine stopped.


when engine at idle manifold pressure should ve about 0.4 bar


if it doesnt move you likely have intake leak or map sensor is bad


i think your guage might be reading incorrectly


you pi\di ratio seem very odd seems to be 0 to 100%


can you screenshot the pi\di tables

[Irace86.2.0]

Originally Posted by steve99

raw manifold pressure should be aprox 1 bar with ignition on but engine stopped.


when engine at idle manifold pressure should ve about 0.4 bar


if it doesnt move you likely have intake leak or map sensor is bad


i think your guage moght be reading incorrectly

No. The gauge works. My brain doesn’t

I’m feeling particularly stupid lately. Apparently I can’t read my own gauge. PSI up top and inHg for vacuum. I was suggesting my idle vacuum was 20 psi , but it is 20 inHg, which is 9.8 psi of vacuum or 0.32 in absolute bar.

My car runs perfect. My post was a comparison to help him, but I’m butchering things, so I’m going to bow out.

[Ultramaroon]

Originally Posted by Irace86.2.0

No. The gauge works. My brain doesn’t

I’m feeling particularly stupid lately. Apparently I can’t read my own gauge. PSI up top and inHg for vacuum. I was suggesting my idle vacuum was 20 psi , but it is 20 inHg, which is 9.8 psi of vacuum or 0.32 in absolute bar.

I wouldn't be too hard on myself. If it's a common thing to switch unit systems at the zero crossing, that's a terrible design; especially without any other obvious visual cues.

[tomm.brz]

Originally Posted by steve99

you pi\di ratio seem very odd seems to be 0 to 100%


can you screenshot the pi\di tables

Steve he got 100% PI on the log because he logged a cold start!

[steve99]

Originally Posted by tomm.brz

Steve he got 100% PI on the log because he logged a cold start!

yeah could be, coolant and oil about 85c but might be still in cold start mode


bit concerned when it revs to 2500 di is at almost 6ms. port about 4 ms Its on 70% ethanol , seems to have some unusual pi/di if its boosted on ethanol with stock injectors looks like it will run out of injector

[tomm.brz]

Originally Posted by steve99

yeah could be, coolant and oil about 85c but might be still in cold start mode


bit concerned when it revs to 2500 di is at almost 6ms. port about 4 ms Its on 70% ethanol , seems to have some unusual pi/di if its boosted on ethanol with stock injectors looks like it will run out of injector

i do not see anything wrong in Irace2.0 log
the pi ratio is definitely because it s still in "cold start" mode.. a. k. a cranking at 100% PI, brief switch to 50% and then again to 100% PI... and then it would switch to the tune tables, like when it is revving to 2500 steady and then he blips... There, the pi ratio is following the tables (in this cases it stayed at 0% PI)

The 6ms of DI opening you see after the steady rev to 2500rpm (precisely 6.53ms),it s not worrying because it is with a low fuel rail pressure.. if you zoom the log you see then the fuel rail pressure rising to near 20mPa and then the DI duration goes under 6ms all the time
And also i m sure that at higher loads and rpm, and with the fuel rail pressure at maximum, there will be much more % of PI and so lower DI opening time

Yeah he definitely has the "unusual" PI ratio that Delicious use in their flash n go tunes, very low PI% at low loads that increases a lot at very high loads

[snowtaipan]

Originally Posted by localhost

Your issues sound almost identical to mine. I spent nearly 2 months diagnosing it and it ended up being the BPV. Here's my thread if you want to compare datalogs and such:

https://www.ft86club.com/forums/showthread.php?t=137808

The TL;DR is that it was a combination of an absolutely garbage tune from Edelbrock as well as a faulty BPV which didn't seem faulty under multiple smoke/pressure tests.

I appreciate the input and it's more data points for me to bounce off.
I don' think the issues are the same. Your LTFT is no where near as jacked up as mine is. It also looks like the way I'm running I'm movinf more through the MAF and more through the fuel system. Also your STFT seems more of the issue, and your overall trims are worse at high RPM whereas mine are better overall ex your overall FT (ST+LT)@2000RPM= 39, my overall FT@2000rpm=2.

I am noting again that I do not have a fuel rail pressure reading. Anyone got insight?

Just my $.02: Edelbrock has been around since 1938 and arguably has one of the best reputations in the business. I can see that the BPV is a regular issue, as it is with most SC's, but I'm not willing to trash their tune. I don't want to believe that such a well respected company would put so little into their tune.

[Irace86.2.0]

Originally Posted by steve99

yeah could be, coolant and oil about 85c but might be still in cold start mode


bit concerned when it revs to 2500 di is at almost 6ms. port about 4 ms Its on 70% ethanol , seems to have some unusual pi/di if its boosted on ethanol with stock injectors looks like it will run out of injector

Dw 770cc

[snowtaipan]

Originally Posted by tomm.brz

i do not see anything wrong in Irace2.0 log
the pi ratio is definitely because it s still in "cold start" mode.. a. k. a cranking at 100% PI, brief switch to 50% and then again to 100% PI... and then it would switch to the tune tables, like when it is revving to 2500 steady and then he blips... There, the pi ratio is following the tables (in this cases it stayed at 0% PI)

The 6ms of DI opening you see after the steady rev to 2500rpm (precisely 6.53ms),it s not worrying because it is with a low fuel rail pressure.. if you zoom the log you see then the fuel rail pressure rising to near 20mPa and then the DI duration goes under 6ms all the time
And also i m sure that at higher loads and rpm, and with the fuel rail pressure at maximum, there will be much more % of PI and so lower DI opening time

Yeah he definitely has the "unusual" PI ratio that Delicious use in their flash n go tunes, very low PI% at low loads that increases a lot at very high loads

Back by popular demand... MOAR DATA LOGGIES
https://datazap.me/u/snowtaipan/driv...&data=11-24-27
Driving data log (I apparently didn't select all the parameters I mean to...)
Look at AFR actual, LTFT, and MAF g/s... It looks like as my MAF reads less incoming air, ECU sees a lean condition and raises LTFT. MAF looks like it lines up with throttle angle. maybe the MAF is just calibrated wrong?

[Irace86.2.0]

Originally Posted by snowtaipan

I appreciate the input and it's more data points for me to bounce off.
I don' think the issues are the same. Your LTFT is no where near as jacked up as mine is. It also looks like the way I'm running I'm movinf more through the MAF and more through the fuel system. Also your STFT seems more of the issue, and your overall trims are worse at high RPM whereas mine are better overall ex your overall FT (ST+LT)@2000RPM= 39, my overall FT@2000rpm=2.

I am noting again that I do not have a fuel rail pressure reading. Anyone got insight?

Just my $.02: Edelbrock has been around since 1938 and arguably has one of the best reputations in the business. I can see that the BPV is a regular issue, as it is with moth SC's, but I'm not willing to trash their tune. I don't want to believe that such a well respected company would put so little into their tune.

It is not “their” tune. It’s CARB’s, and it might not be as accommodating as an OEM tune for all altitudes and weather conditions. You would want to hear from other members who have the CARB tune at altitude if they ran into any problems. With that said, I don’t think your issue is with the tune either; it is just a possibility I wouldn’t dismiss.

It seems you are making plenty of vacuum, now that someone has oriented my brain to inHg values. You are making boost too.

Odd about the fuel rail pressure. Check the sensor connection. It obviously isn’t zero or your car wouldn’t run.

Check that your BPV is the newer, two bolt version versus the three bolt version, but I’m still thinking something with the direct injectors.

[tomm.brz]

i ll take a look at log soon

about fuel rail pressure
if you have fuel rail pressure at 0 all the time very probably it is a older racerom(maybe rr10) that was bugged with K00C and also affects other values

[CSG Mike]

Originally Posted by Irace86.2.0

It is not “their” tune. It’s CARB’s, and it might not be as accommodating as an OEM tune for all altitudes and weather conditions. You would want to hear from other members who have the CARB tune at altitude if they ran into any problems. With that said, I don’t think your issue is with the tune either; it is just a possibility I wouldn’t dismiss.

It seems you are making plenty of vacuum, now that someone has oriented my brain to inHg values. You are making boost too.

Odd about the fuel rail pressure. Check the sensor connection. It obviously isn’t zero or your car wouldn’t run.

Check that your BPV is the newer, two bolt version versus the three bolt version, but I’m still thinking something with the direct injectors.

CARB only approves (or disapproves) of the tune. Edelbrock's tunes are developed in-house on their engine and chassis dynos.

[snowtaipan]

Originally Posted by tomm.brz

i ll take a look at log soon

about fuel rail pressure
if you have fuel rail pressure at 0 all the time very probably it is a older racerom(maybe rr10) that was bugged with K00C and also affects other values

So n00b question: how do I tell if the ROM is up to date?
The supplied ROM is a ZA1JK00C for 2017 BRZ Manual but I don't see the update me warning at the top of the toolbar.

[tomm.brz]

Ok i'm 99% sure it is just the airflow calculation (either entirely maf, or hybrid SD, could be, whatever) at idle that it's wrong
The codes you get are caused by this high ltft, that 's not caused by a leak but it is necessary actually to run the right afr.. but it causes a rough drive at low rpm I 'm sure you feel it

While there is 37% ltft at idle, the stft is already working against it while car is warm, and with still a total correction of around 20-25%, the fuel quantity total at idle is extremely low
the maf scaling/speed density is off at low values, and 100rpm more on the idle will also help
it's also a bit off in open loop, but at the other extreme since it is a bit too rich

Tune is not pretty, rich with very relaxed ignition timings

also i think it can be racerom version 10 that was pretty bugged for US 2017 cars