Progress Thread finally tuning (and more)

[JD1964]

Thank you Noobz for the analysis of the logs. My initial response;

1. I'll keep the current NA tune unchanged pending any discovery of the fuel trim imbalance.

2. Wideband gauge in car and value displayed on log screen are not identical but average a difference of about .1 with the gauge in the car reading .1 richer. The gauge and the log parameter are both set for gas.

3. O2's were replaced as a new pair in 2014 and approximately 20k miles ago. Bosch 13942 is the part number.

4. I will check O2 wiring for any concerns and correct if needed.

5. I will check for exhaust leaks at the noted locations and correct if needed. (none known at the time of this writing)

6. I will check for vacuum leaks and correct if needed. (none known at the time of this writing)

7. I will check ignition components and spark plugs. I'll photograph plug coloration and post pictures. Plugs are new 3923's

8. I will monitor the bank difference for any future changes and compare to existing log data.

9. If I dont find any intake or exhaust leaks, the first thing I might do is swap the O2's side to side and see if the imbalance follows.

10. If all else does not identify a condition that would explain the imbalance, I will send the injectors out for servicing.

One question at this point. Is it possible that the combo under this new tune needs some additional time to settle in where it may report more balanced fuel trims after adequate time?

Thanks, John D

 

[JD1964]

Here’s pictures of plugs. They are Autolite 3924’s. Pencil marks indicate location. Maybe 100 miles on these

 

[JD1964]

Bosch 942. I’m going to swap sides when I put them back in. The wiring and connectors look good.

 

[Noobz347]

The switching of the two sensors compared to the wideband looked very good too.

 

[JD1964]

I see or hear nothing suspect of vacuum leaks. No exhaust leaks anywhere upstream of the O2's. No dry rotted or cut hoses and all vacuum connections clamped where necessary and others tight. PCV valve to its new grommet in the intake were sealed in there with RTV when I put intake back on last time. Obviously these are new intake gaskets with the recent head swap. New Remflex header gaskets.

The base of the spark plug thread body (part that is exposed in the combustion chamber) of plug #2 is darker than all the others. Heres #2 compared to #5. The rest of the plugs look mostly like #5. Maybe something is up with #2 injector? If it were dumping more gas than the others, would that explain the ECU working to pull gas from passenger side?

 

[Noobz347]

It is possible but I have no way to tell.

The plug on the right does look a bit 'sooty'. Do you have any oil sitting in the intake behind the throttle body?

 

[JD1964]

It is possible but I have no way to tell.

The plug on the right does look a bit 'sooty'. Do you have any oil sitting in the intake behind the throttle body?

no oil on the intake under/behind TB

 

[JD1964]

Well, before I get some more logs with O2's swapped sides I'm going to take care of another minor issue since I already have it on stands. I have a small pesky coolant leek from the drivers side most forward lower head stud. I need to drain the block, pull that stud, clean up those threads and redo the thread sealer. That is the only one leaking and luckily its one thats easy to get to

 

[JD1964]

Im going to swap position of plugs 2 and 5. That way I have a cleaner one where the dirtier one was. See what happens when I inspect them next time.

 

[Noobz347]

Once you get a data log in the new config, if nothing changes, you might try swapping that injector with one from the opposite bank.

Don't want to make too many changes at once.

 

[JD1964]

Once you get a data log in the new config, if nothing changes, you might try swapping that injector with one from the opposite bank.

Don't want to make too many changes at once.

If I get to the point I pull the upper and pull the fuel rail, all the injectors are going in for service. Let’s see what the O2 swap shows and then go to whatever the next step will be. I finished resealing the leaking head stud a little while ago.