What's going on here?- log

[DrX]

Everything looks and sounds good at startup and the NB O2s for both banks are in agreement. After 20 seconds or so, bank 2 starts to drop. Once it goes into closed loop the strims will work their way up to 30% difference between the banks. If I turn the key off and restart, the pattern repeats. Good for the first 20 seconds. With only 5* of overlap on the cam, idle is smooth at startup, but it gets sightly lumpy after running the 20 seconds.

I have tried swapping O2s, new O2s, and swapping the injector drivers around, all with no effect on this. The idle is more chunky in this first startup vid, but I found that one of the drivers had a bad transistor. Fixed that.

Ignore the widebands, I'm still trying to get these damn LC1s to work properly. Not sure if the bank assignments match up to the NBs any more at this point. Ignore the IAT as well, I have to make up an extended sensor. It is barely protruding through the huge mass off aluminum at the front of the lower intake.

Log and tune files are attached below. I turned the key off a couple of times during the log.

http://i114.photobucket.com/albums/n241/TDOC2004/th_TwinBlown427AVFirstStart.jpg (http://s114.photobucket.com/albums/n241/TDOC2004/?action=view&current=TwinBlown427AVFirstStart.flv)

[DrX]

Here's a log with a cooler start. Notice how both banks start out even then one heads up and one down before trimming kicks in. Lots of key off/ons in this log.

[joecar]

Very interesting...

LTFT's are disabled, but CL is still enabled via B4205, so only STFT's are applied.

It looks like when it tries to go into CL after the delay the following happens:

HO2S11 is averaging high (it seems stuck high well above the switch point) and so the STFT is trying hard to get HO2S11 to swing down.

HO2S21 is averaging low (it swings with an average that is below the switch point) and so the STFT is trying to move the swings up a little.

You said you swapped the O2 sensors between banks, andthen got the same results (the results did not change banks)...

Looks like you have different simultaneous problems going on on each bank...
e.g. leaky injectors on bank1 and airleak on bank 2, or some other combination...

hmmm... or maybe there's a wiring problem...

[joecar]

Also, MAP seems to read high while idling, and then drops when throttle is opened some... that isn't right...

when throttle is opened MAP should go up...

so there may be an airleak at the manifold.

[DrX]

Thanks for the input. Based on the MAP values I was suspecting an intake leak as well-although I don't see how as everything lined up- could be the gaskets aren't thick enough, or maybe there was a tear- there is 150 lbs sitting on top of them. I have gone over everything else. Injectors hold pressure for a while if I block off the return from the FPR. I would have preferred a wiring problem. This is a pretty crowded pile of parts to work on-even in a truck.

What threw me was that today I looked at the startup areas of the logs because I thought that it always sounded great for the first while after startup. Not sure of the mechanism as to why both banks start out equal then begin to diverge before the trimming even kicks in. Cold or hot, it always run better for the first 20 seconds.

The tune was setup in STRIM VE Fixer fashion for the RoadRunner.

http://i114.photobucket.com/albums/n241/TDOC2004/IMG_0072.jpg

[DrX]

Signs of leakage around # 6 and # 8 ports. Possibly 2 and 4.

http://i114.photobucket.com/albums/n241/TDOC2004/IMG_0663.jpg
http://i114.photobucket.com/albums/n241/TDOC2004/IMG_0660.jpg

I R n R'd the whole works, installed new gaskets, and took a pic of the bottom of the gasket at #8 port through the injector boss.

http://i114.photobucket.com/albums/n241/TDOC2004/IMG_0717.jpg

Fired it up today and it still behaves the same except that the spread between the banks is less now! :cussing:

[joecar]

Post new logs.

Can you give me some guidance on the pic thru the injector bore... what are the features I see...?

[DrX]

Post new logs.

Can you give me some guidance on the pic thru the injector bore... what are the features I see...?

The arch shape across the top is the periphery of the boss. The larger object on the right is just the back end of a small light bulb I fished inside the intake. The horizontal black line is the gasket at the lower end of the port. Below the gasket is the intake port of the head. While no obvious gap is evident, inspection of the old gaskets confirms that the material around the upper half of the ports is better compressed than that around the lower 1/2. i.e you can see the swirl marks from the metal in the upper 1/2 of the gasket, but the lower portion is not impressed at all. So it looks like the taper of the intake does not quite match up to that of the heads. Might have to work out a better way to seal the intake to the heads.

Will post up a log in a bit. IATs are still very high cruising and idling but cool off in boost, even with the extra long sensor I rigged up. MAP still behaves as before. I didn't touch the boost VE table, but now it is lean while before it was rich. Maybe I am blowing less boost out through the gaskets now. It does run better now out of idle.

[DrX]

Todays log and tune attached.

One more question........Why does the commanded AFR not change in boost?

Thanks for looking at this Joe.:cheers:

[joecar]

You are welcome...:cheers:...I learn new things by looking at log files.

Hmmm... the STFT behaviour is now different...

[DrX]

You are welcome...:cheers:...I learn new things by looking at log files.

Hmmm... the STFT behaviour is now different...

These are new sensors.......again. And I have moved them downstream from the collectors another 12-18 inches as the cats were removed from the Y when the exhaust was finished up last week. The widebands were in the collectors, but are now just after the collectors in the Y pipe. The widebands seemed to be working OK after a firmware reflash but bank 2 crapped out again after I had it running for a while yesterday, so I wouldn't trust it. It also seems to fluctuate more in the logs than the bank 1 sensor. I tried tuning off a Bank 1 & 2 averaged BEN, but that wasn't working out as well as the averaged STFTs. It actually made things worse. These are fresh injectors as well - still 95lb/hr. No source for the correct offsets, etc.

I don't know if idle will ever be perfect with the lower intake being a large wide open runnerless box, but right now there doesn't seem to be a desired airflow that it particularly likes. Without the spark correction active it will start surging and die.

[DrX]

Maybe I just need to ignore the STFTs. Seemed to run pretty good today in open loop. Other than that boost is rich again after I bumped up boost VE by 20% and disabled STFT.

http://i114.photobucket.com/albums/n241/TDOC2004/th_PlayinwithTwins.jpg (http://s114.photobucket.com/albums/n241/TDOC2004/?action=view&current=PlayinwithTwins.flv)