JB4 2018 Wrangler JB4 - N54Tech.com

Ronmaf · **JB4 2018 Wrangler JB4 -** 07-05-2020, 03:14 PM

Hi, I purchased the JB4 tuner and have noticed a sharp decrease in fuel economy. I am not dogging the engine at all I am driving normally as I was before I installed the JB4.
I am running it on the default stock settings that came with the unit. I don’t have any of the cables are Bluetooth connectivity to look at it in anyway. My question is are these results normal? Do I have to buy more accessories to troubleshoot a product that should work out of the box, or is this supposed to be customized from the start For my specific Jeep.
Other symptoms are that on rural highways the jeep doesn’t want to shift into 8th gear. This only happens at around 50 to 60 mph. Over that speed it ****s to eight deer and cruisesfine.
Any help would be greatly appreciated, thank you.

Terry @ BMS · 07-05-2020, 04:44 PM

If you're racing around a lot then I'd expect to get lower economy. Beyond that should be no difference. Once you add on a bluetooth or data cable to change maps you can easily enable/disable the JB4 to better evaluate your economy differences.

Ronmaf · 07-05-2020, 05:10 PM

I will order the Adapter tomorrow. I would like to know why the fuels economy went down so hard. I am averaging about 7mpg less than before installation.
Thanks for the quick reply.

Ronmaf · 07-08-2020, 05:44 PM

Quote:

Originally Posted by Terry @ BMS

If you're racing around a lot then I'd expect to get lower economy. Beyond that should be no difference. Once you add on a bluetooth or data cable to change maps you can easily enable/disable the JB4 to better evaluate your economy differences.

Hi Terry, I have the Bluetooth connectivity now and have tried several different tunes. Is there somewhere I can read about how to customize the tune and to get the gauges to work on the app? I would also like to see how the built-in tunes are set. Is there a way to read those tunes to see where the boost is at what rpm etc.

Terry @ BMS · 07-08-2020, 06:21 PM

If no data in app other than boost let's check the obdii install. Photos of both sides?

Ronmaf · 07-09-2020, 04:38 AM

Please see attached

Terry @ BMS · 07-13-2020, 08:34 PM

I can see it's wrong in the photo...

Ronmaf · 07-15-2020, 06:13 PM

Quote:

Originally Posted by Terry @ BMS

I can see it's wrong in the photo...

Thanks Terry,
I fixed that. Seems my MPG is based on the canned time boost. I did a custom tune with no boost till 2000 rpm. Mpg went up. I also noticed that the transmission will not up shift to 8th gear at cruising speed unless above 62mph. This drastically reduces MPG. The Jeep JL Etorque operates up to 1500rpm. How does the tuner effect shifting or does it? My work around has been manually shifting to 8th gear, but I shouldn’t have to.
Any ideas?

Ronmaf · 07-18-2020, 10:08 AM

Quote:

Originally Posted by Ronmaf

Thanks Terry,
I fixed that. Seems my MPG is based on the canned time boost. I did a custom tune with no boost till 2000 rpm. Mpg went up. I also noticed that the transmission will not up shift to 8th gear at cruising speed unless above 62mph. This drastically reduces MPG. The Jeep JL Etorque operates up to 1500rpm. How does the tuner effect shifting or does it? My work around has been manually shifting to 8th gear, but I shouldn’t have to.
Any ideas?

Can anyone offer some advice? My MPg should not be this with this tuner.

Drdirtbag · 02-12-2021, 04:01 PM

Hello new to forum, installed jb4 on 2019 Jeep Wrangler rubicon 2.0 turbo, no issues. Apparently map 1 is the default map, I have not really “tested “ the install yet, but with just rapid exceleration there seems to be a harder pull. My experience is with liter bikes, and fuel management system enhancements are noticeable immediately without much “tuning”. I’m interested in low to midrange improvement In performance. Does this mean I need to change existing map or is there something available that would become my go to map. Any help much appreciated. Thanks