3.3TT JB4 App Freezing & Ignition? Issue

[k8blackout]

Hello! I've had the JB4 on my Stinger ('21 3.3tt RWD, 57k) for probably a good six months now, at least, and I've had a lot of time to mess with it and such. I've got intakes, FMIC, and Denso 1 step plugs, the Densos are anywhere between 12-16k miles but have felt good up until now.

To preface, I did go on a drive the other night during a pretty heavy storm and drove through some pretty deep water, nothing crazy, but definitely more than ankle deep water in some parts, and all of the issues below happened 15-45 minutes after said water exposure. So it's not necessarily the smoking gun, but keep that in mind I guess.. lol.

So after my little drive I began to notice my car was having trouble under ~50% load or greater, the JB4 gauges freeze, the map resets to 0 (i can only tell after restarting the app since it's frozen), but the app is still responsive. I have the windshield stalk map hotkeys and those still update when I change them while the app is frozen, but the gauges like RPM, boost, etc... all are frozen at some value. The bigger issue is my car has this weird sputtering/struggling feeling above 8-10 pounds of boost. I've tested it in Map 8, 0, 1, 2.. map 8 definitely does it the least, and in anything Map 0+, it's more often than not that it gives that weird sensation. It is a similar feeling to if you've ever had a bit too much boost and the HPFP starts to struggle to provide gas, or similar to if you have bad plugs. Sometimes it runs fine, smooth as butter, and other times it will start sputtering really badly and I refuse to hold on the pedal. There is a third scenario where it kind of lacks responsiveness, and progressively kicks up in power until it's at full boost. Since the JB4 app freezes, it's kind of hard to get a log because it stops logging too. I tried to use one of my external scanning tools but it isn't fancy enough to get good readings for me to actually make any conclusions. There are also no CELs or other issues.
I am planning on changing the plugs, since they probably need it anyways, but I pulled one the other night after the issue began and it honestly looked fine; clean, had a lot of electrode left. Sure, one of them could be bad or cracked, so I will replace them, but I fear that's not the issue.

I have already tried fully removing the JB4, however the issue still occurs. This is what leads me into suspecting it's a wiring issue - the JB4 freezes/crashes, so perhaps there's a short or some sort of surge coming from some area of wiring that the JB4 uses, causing it to do that? It would be helpful to know where exactly the JB4 pulls its power from, or if anyone's had a similar issue and could maybe guide me to checking some areas of the car for corrosion or issues, that would be great.

I know there's not much descriptiveness here, and I could go and take a video of it actually happening, but I will at least attach some logs that may be of help in diagnosis. They're all labeled either good, bad, or culprit, meaning the car ran fine, the JB4 crashed, or there's some value out of place that may be able to help diagnose the issue. Any help is appreciated, and do ask if you need any more info. Thanks y'all.

FYI: I labeled the Map 0 and 2 'culprit' because right before the logs stopped, JB4 crashed, and map reset to 0, you can see IGN1 crash.
Bad Map 1 is just a short and sad map where it crashed right after logging began. Not much I could do. I tried progressively pressing the pedal on some of the logs too to try and get it to at least get under boost before it crashed, generally with no luck.

 

[Thomby]

I have already tried fully removing the JB4, however the issue still occurs.

Do you mean you have issues with the JB4 removed, or just that the JB4 has issues after reinstalling?

I would expect the connectors to be pretty robust against even a big splash, assuming they weren't completely submerged. Same thing with the JB4 itself...I wouldn't expect the aluminum block to be water proof, but it should be pretty resilient to any kind of splash. Have you checked both connectors and circuit board for moisture/corrosion?

 

[k8blackout]

Do you mean you have issues with the JB4 removed, or just that the JB4 has issues after reinstalling?

I would expect the connectors to be pretty robust against even a big splash, assuming they weren't completely submerged. Same thing with the JB4 itself...I wouldn't expect the aluminum block to be water proof, but it should be pretty resilient to any kind of splash. Have you checked both connectors and circuit board for moisture/corrosion?

The issue happened both with and without the JB4 connected. I ensured the JB4 was looking good when I took it off and rewired it back on and other than it freezing it works perfectly fine under normal conditions. I opened it up and I didn’t see moisture or anything, the connections are a little rusty from time but they’ve worked fine until now and as I said before even without the JB4 connected it was still actin funny.

An update to the situation is I got an engine code for a cylinder 5 misfire. Inspected the plug, looked fine. No cracks, no weird colors, has plenty of electrode left. I’m now about to test for a faulty ground/short from the block to the frame I just have to find a piece of bare engine metal to use. My other option would be to try a new boot for #5 or to try and manually find an electrical issue that only happens under throttle.

 

[k8blackout]

Update 2: when I use a volt meter and touch one probe to frame and the other to bare engine block metal, it gives me a l voltage reading, albeit very small, but a reading. Is that normal? I would think not?

 

[Thomby]

Rust on the JB4 harness/sensor plugs, the JB4 circuit board, or the car's harness/sensors? For a car this new I wouldn't expect any rust/corrosion on connectors...how much water did you go through?

I would probably be pulling any accessible wiring harness plugs under the hood to check for moisture and corrosion. You can check your coil packs while you're at it.

Probably worth disconnecting intake piping to see if you sucked up any water...air filters to turbos, intercooler connection, and intake to throttle body. Doesn't sound like you hydrolocked (you'd be seized or at least have rod knock), but maybe you have some sitting in your intercooler or lower bends of your piping. And it might also be worth draining a bit of oil to see how that looks (any water should sink to the bottom).

How much voltage between block and chassis? If it's millivolts it's likely noise, or maybe the galvanic difference from steel vs. aluminum.

 

[k8blackout]

Rust as in rust on the JB4 side of things, nothing hampering just surface rust on some internal parts of the JB4. No rust on any car harnesses or connectors I can see which is normal.

I do now have plans to go under the car and disconnect all the different harnesses and undo things to test and see if there’s water stuck anywhere, and while I’m down there I could maybe undo one side of the IC to ensure it’s dry, not likely, but nonzero for sure.

The voltage between block and chassis is minimal, closer to mV than anything so as you were saying most likely just noise. I also tried to clamp block and frame together to create a ground and they didn’t do anything anyways.

I’ll end up doing those things sometime this week and if that doesn’t work I’ll just strip her of mods and let Kia have at it.

 

[Thomby]

I can't recall seeing the Stinger's specifically, but many (most?) cars have an actual ground strap connecting the block to the chassis, vs. relying on the engine mount bolts, so I'd be surprised to ever see anything above a mV or two.

Can you grab a picture of the rust? That just doesn't sound like something that should be possible, without submerging your car.

 

[k8blackout]

I can't recall seeing the Stinger's specifically, but many (most?) cars have an actual ground strap connecting the block to the chassis, vs. relying on the engine mount bolts, so I'd be surprised to ever see anything above a mV or two.

Can you grab a picture of the rust? That just doesn't sound like something that should be possible, without submerging your car.

Yeah it was in the very small numbers, I think .06V when connecting block and frame. I’ll take a pic of the rust tomorrow, to be fair my JB4 is quite old, I’ve had it for 6 months but I bought it secondhand and it is one of the very original ones for the Stinger from the looks of it, got some ‘older technology’ on it but still functionally identical.