Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!
juergen.scholl, I can't say for certain, but it has always been my suspicion that initial startup operated in Open Loop, or there was some sort of initial enrichment table that provided enough fuel....or a combination of the two. This would make sense with what scannerjohn is suspecting regarding the O2 sensor heater circuit failure.......would you agree?
Here are some screen shots from today.I ran the engine longer than I've ever run it since the rebuild. The longer it ran, the worse it idled.....but it always clears up around 2000 rpm.All graphs are at idle. Again, everything clears up after 1500 RPM. Bank 1 and Bank 2 are basically identical after 1500 RPM.
P0051 and P0057 both bank 2 O2 heater circuit faults. With AF's the heater circuit has to be working else the 02 will not function correctly. Their heat range is over 1200 degrees F as apposed to narrow band around 600. Check the power and ground for those two 02's.
"an open mind let's knowledge flow in and wisdom flow out for a man who has neither never listens to those who have both".
Being wrong doesn't bother me, it's being right and not understanding why that does
I'll check power and grounds over the weekend. I've done some of this already and I'm pretty sure I do have good power and grounds.
And if they are good, we have bad sensors......correct???
I have a busy Easter weekend so I might not reply until Monday.
And so Happy Easter everyone!!! Please remember the sacrifice Jesus made for us some 2000 years ago and celebrate the victory over death!!!!!!!!! Amen and Amen.
How did the harness routing go? There may be a couple of connectors on these that are able to be swapped too without knowing they're wrong. Maybe injector connectors and vvt connectors?
Edit: I scanned over the posts before posting the above. Now after reading through it all, my info doesn't sound helpful. Great, now I have to scramble to try to add some value.
The only other thing I can think of that could impact an individual bank is if this engine has those two swirl valves on the intake. Not sure if those came in later models or not.
When you say you let it longer than ever, were all of the recordings done at full operating temp?
Is there misfire counter in mode6 to see if it's only showing up on #4?
The heater circuit codes are probably going to get you where you need to be now though!
Jurgen is right the way I see it you have to stop going down rabbit holes and go back to basics you can eliminate all the factors both banks share and look at what they don't share.
That you don't get the issue at initial start up when the engine is getting cold start enrichment and is in open loop immediately eliminates and fuel pressure issue it points towards a control issue.
You did a lot of work on the vehicle is it possible that the wiring for the injectors or O2 sensors is confused -- ie Bank 1 injector wiring to Bank 2 or upstream and downstream O2 wiring swapped over --- at the back of my mind is a vague recollection of something I read years back about Nissan O2 sensor wiring connectors.
" We're trying to plug a hole in the universe, what are you doing ?. "
(Walter Bishop Fringe TV show)
