[XCCOS]

I'm looking for support on how to troubleshoot and fix a lean AFR issue I have when I run the JB4.

2017 Q50 3.0t base AWD, JB4 w/ FW, 91 octane, 5500' elevation, temps ranged from 85-100+ though this issue occurred in lower temperatures as well.
No other mods are included on the car.
I'm attaching a log from the day and may include others if I can sort through them to find the ones I've viewed before. Map 6 is set to +1 PSI until 5500rpm and I tried maps 2 and 1 to compare them.
I would appreciate support from BMS staff, but anyone's input is welcome.

[JCB]

I'm not BMS but from looks of the log, the low AFR is probably a symptom of something else. Car is barely making any boost. Even so, it seems too slow - pretty sure if I did a zero to sixty in valet mode on mine it would be faster - yours is running 8-9 seconds to sixty according to the time stamps in the log. I also see throttle cuts where I would not expect to see them. Usually only see that when there is tire spin or someone hit the rev limit.

I would get the car checked out at a qualified shop or dealer. Something is not right. How did it run before JB4? Stock the car should have been WAY faster than what you have in this log.

[XCCOS]

Originally Posted by JCB

I'm not BMS but from looks of the log, the low AFR is probably a symptom of something else. Car is barely making any boost. Even so, it seems too slow - pretty sure if I did a zero to sixty in valet mode on mine it would be faster - yours is running 8-9 seconds to sixty according to the time stamps in the log. I also see throttle cuts where I would not expect to see them. Usually only see that when there is tire spin or someone hit the rev limit.

I would get the car checked out at a qualified shop or dealer. Something is not right. How did it run before JB4? Stock the car should have been WAY faster than what you have in this log.

Thanks for the reply, JCB. We may have corresponded previously as I've had this problem before. For reference on how slow the car is, when it is getting those lean AFR numbers, it does back off strongly to preserve the engine. Additionally, the conditions were not ideal. The elevation is over 5500' at 100+ degrees and running 91 octane. Not exactly a world beater on that day. Otherwise, with the JB4 disabled, I do not get such drastic AFR spikes and my friend had noticed how considerably better the car runs when just giving a pull on the highway in better conditions (lower temps and humidity in particular). He and I will drive each other's cars from time to time for fun, so we've both experienced the difference. Also, I have had it to a service center that said they could not diagnose any issue with fueling on the car. I've since reached out to Burger Support, so once I am able to get more information with their assistance, I will try to post back here.

[JCB]

Now that you say that it does sound familiar! Sorry you keep just getting me answering your posts...very few eyes on the Infiniti section of this site these days! Hopefully the JB4 is causing the issue somehow and support will be able to help you out!

[XCCOS]

No worries! I appreciate you at least providing a reply. I am assuming support can help because this does not occur when I have the JB4 deactivated. I'll put any resolution I get on here in case others run into it though.

[Terry @ BMS]

Boost seems really low. Is the car in limp mode? Boost leak? Map0 log?

[XCCOS]

Originally Posted by Terry @ BMS

Boost seems really low. Is the car in limp mode? Boost leak? Map0 log?

The car hasn't gone into limp mode, though it certainly feels like it when the boost is cut under those lean conditions. I have another log in Map0 and then Map1 to compare the two. I sent these to the customer service team as well, but was just told, "Looks fine here. You can use Map 3 next," which is not the response I was expecting to recieve.

This log is after following the customer service reps advice of ensuring that the firmware is up to date and removing the fuel wires from their connection.

[Terry @ BMS]

Something is wrong with the boost.

Let's see the map0 log.

[XCCOS]

Originally Posted by Terry @ BMS

Something is wrong with the boost.

Let's see the map0 log.

The file I uploaded has the Map0 (ends on line 70) and Map 1 after that.

[Terry @ BMS]

I scrolled along and didn't see any map0 runs. Car appears to be in limp mode of some sort by the end of the log. I'll check the scaling for the elevation but record a true map0 run please.

[XCCOS]

Originally Posted by Terry @ BMS

I scrolled along and didn't see any map0 runs. Car appears to be in limp mode of some sort by the end of the log. I'll check the scaling for the elevation but record a true map0 run please.

Sorry, looks like I may have selected the wrong run and chose the one from my original conversation with the service team. Attached is the Map0 to Map1 run.

[XCCOS]

Any updates you can give me based on the previous logs? This run was on a less aggressive map because I've ran into such dangerous AFR conditions going higher, so I'm hoping there may be some solution for this.

[JCB]

I really think there is something wrong in your fuel delivery. Since it is on both banks, I would suspect it to be a fuel pump. I would see if you can get both your low pressure and high pressure fuel pumps checked. JB4 is just "fooling" your car into adding additional boost. It is not setting AFR targets (or even influencing them without fuel wires setup and active). On map 1, at 4000 RPM your trims drop dramatically and your AFR goes to that dangerous level. On the Map 0 run, the car never needs that much fuel because of the lower boost.

I have looked at a lot of logs over the past 2 years and have never seen or even heard of this issue. That also leads me to believe iits a problem with the car, and not JB4 caused. The extra boost with JB4 is likely just exposing the issue.

[Terry @ BMS]

I assume EWG and fuel control wires are not installed?

[XCCOS]

That is correct, neither EWG nor FW are installed. Howevwr, FW were disconnected at the suggestion of the customer service rep.