S54 running (slightly) rich

[bagger]

I has been waiting for 7 month for the data log…

Hot idle data of pre-cat O2, MAF, rpm, engine temperature - for how long? I can do this tomorrow and post it. I don't have a wideband - it's a stock car (minus eventuri), no tunes.

[bagger]

sapote https://datazap.me/u/jeffbagnall/log...-5&axes=shared

I think I did it right? Not sure. First time. Have a look - thanks! 5 minutes worth of logs.

A couple more things. Last night I was able to get a couple more screw turns on the MAF housing securing the MAF to the eventuri coupler. I think it made a little bit difference in the shuddering feel? I don't know.
The other thing is the solenoid is really clicking loud. Obviously I'm hyper sensitive to sounds and feels right now, but I have never heard this thing before and it keeps clicking loudly -- details in my post here: https://nam3forum.com/forums/forum/m...f-my-fuel-rail

I wonder if I just have a small leak somewhere. I might smoke test again.

[sapote]

Hot idle data of pre-cat O2, MAF, rpm, engine temperature - for how long? I can do this tomorrow and post it. I don't have a wideband - it's a stock car (minus eventuri), no tunes.

Perfect with stock parts. why not also include post cat sensors just to see the condition of the cats? log for 2 to 3 minutes.

Btw, I beat AI on log data analysis every time

[bagger]

AI still has a long way to go with troubleshooting stuff - no doubt. I trust this forum way more!

Here is a new link with post cat 02's added: https://datazap.me/u/jeffbagnall/logs/cmr9qkchi000bjo0670xxssel?channels=2&sizes=100&sc= 2-4-5-6-7&axes=shared

While the car was warming up I unplugged the MAF, and still felt the shudder/vibration. Plugged the MAF back in, and then unplugged that electrical plug to the secondary air thing, and still felt the shudder/vibration. The data in the link was after I was messing around with that, everything was plugged in for that data read. I turned the car off and then on for this data file (you see can that in the RPMs). Hopefully this ok enough for you to read - let me know if not. Appreciate it sapote!

I'm still thinking leak somewhere. I'm not smart enough to know if I have an exhaust leak or not - still learning.

[sapote]

Here is a new link with post cat 02's added: https://datazap.me/u/jeffbagnall/logs/cmr9qkchi000bjo0670xxssel?channels=2&sizes=100&sc= 2-4-5-6-7&axes=shared

Sorry to waste your time on this log. I forgot to remind people to include these data in the hot idle 3-minute log:
RPM, MAF in g/s preferred (if not available then lbs/min) , engine T in C, Fuel system status 1 and 2, Intake air T, all 4 fuel trims, pre-cat O2 sensors, and post cat sensors if available.

To tell the condition of the cats, take a drive and log the data with hot engine for 5 min minimum.

[bagger]

Not wasting time at all. Appreciate the help! Here is the latest file. Some of them will be the wrong things because I was too lazy to figure out which sensor or which bank, so I just mapped 'em all.

https://datazap.me/u/jeffbagnall/logs/cmr9v9rux0001kw068ltpgkoz?channels=12&sizes=100&sc=12

This is about 3-4 minutes of idle, and then drove it around in various conditions (45-60 mph) and more residential speeds. I tried to get a good variety of holding RPMs, rowing through the gears, and throwing it up to 5k rpm. At one point, at a stop light, I was playing with the rpms at idle as well. Then I let it idle in the garage for another minute or so after the ride.

Thanks sapote - I don't know what I'm chasing. But this is kinda fun learning new (to me) things!

[sapote]

Your LTFT at idle = 8.6 which is on the high side, and DME needed to add more fuel, meaning it's running on the lean side, not enough to trigger lean code yet. What interesting is that this LTFT trended upward at higher load. Usually for small vac leak, it should trend down at wider throttle. I think maybe the MAF can be a suspect: your MAF is slightly under report, 4.6 lbs/min at idle, should be around 4.8. You might want to swap with a good known MAF and see if the LTFT going down to around 3.5 at idle.
Under-report MAF causes DME to inject not enough fuel, then precat sensors tell DME to add more fuel, hence higher LTFT.

Cats still have a lots of lives in them. They stay solid high at idle, and switch a few cycles during the drive which is normal.
All 4 O2 sensors look healthy switching rail to rail [over 0.8 to less than 0.1]

The STFT swing around zero, so it's normal and so I only focus on the LTFT.

[bagger]

Man, thanks a ton. I forget if I mentioned this or not, but I did clean the MAF with MAF spray while I was in there doing the alternator and eventuri filter cleaning. Maybe one of those two things was a mistake - dunno.

Before pulling this last log, I let the car hot idle in the garage and pulled the MAF connection. The STFT went to -28.1 on both banks. I wonder if that's more evidence that my MAF is acting crazy. As far as I know - it's the original one.

How long does it take for the LTFT values to change? If the issue were my MAF, and I swapped in a new or known good one, would I immediately see the LTFT drop? Or would that happen over time?

[sapote]

Man, thanks a ton. I forget if I mentioned this or not, but I did clean the MAF with MAF spray while I was in there doing the alternator and eventuri filter cleaning. Maybe one of those two things was a mistake - dunno.

Before pulling this last log, I let the car hot idle in the garage and pulled the MAF connection. The STFT went to -28.1 on both banks. I wonder if that's more evidence that my MAF is acting crazy. As far as I know - it's the original one.

How long does it take for the LTFT values to change? If the issue were my MAF, and I swapped in a new or known good one, would I immediately see the LTFT drop? Or would that happen over time?

What did you use for MAF cleaning?
MAF unlugged would cause open loop running, so -28.1 is not a surprise as the open loop default is very rich fuel.
LTFT should change if other variables changed, within 3 minutes, hot engine.

[bagger]

I used the CRC MAF cleaner stuff - nothing crazy.
I'm ordering a new Bosch OE MAF for fun. Will report back when it arrives and I have a chance to see if the LTFT changes after 3 minutes, hot engine.

Thanks!

[Sajk]

From your post.

"think maybe the MAF can be a suspect: your MAF is slightly under report, 4.6 lbs/min at idle, should be around 4.8."

Have you taken altitude into account? Air mass differs at different altitude.