(HELP) Jb4 will crank but not turn over (HELP)

[Acoop]

Hi. I just installed a jb4 into my 2008 335xi and everything worked, Bluetooth conected and I could adjust settings. But everytime I attempt to start the car, it just cranks and doesn't turn over. I bought the jb4 used. Any help would be great. Thanks.

Also thought to add that sometimes there is a loud whining in the front of the car.

[M43S7RO]

Rod bearings are shot.

[Yoko22R]

You might get better help in the e90post forum.

[wfdeacon88]

Make sure you check your engine block. Many of these cars are missing two cylinders, potentially also missing a pleasing exhaust note. Probably not fixable for the existing car.

[pbonsalb]

Try N54tech dot com

[M_Chronos]

Step 1: Remove POS JB4 you bought used
Step 2: Pray POS JB4 didn't destroy (in order) plugs, turbo, pistons
Step 3: Success

[AC/DC]

Originally Posted by Acoop

Hi. I just installed a jb4 into my 2008 335xi and everything worked, Bluetooth conected and I could adjust settings. But everytime I attempt to start the car, it just cranks and doesn't turn over. I bought the jb4 used. Any help would be great. Thanks.

Also thought to add that sometimes there is a loud whining in the front of the car.

You're definitely in the wrong forum, but I had a 335i a long time ago with a JB4 and Procede. Did you ensure that all of your wiring is correct? If you don't have everything matched up properly, it will cause all kinds of havoc. Also, once you check your wiring, how many miles do you have on the spark plugs? I can assure you that if you have >20k miles on them you will get misfires and be in limp mode. Best of luck!

[chocstraw]

M-Snobs are ****.

Check the wiring, make sure everything is in right, make sure that the JB is flashed to the correct vehicle you have, etc. I had some issues getting mine setup too.

N54tech, E90post are better for this. Hope to see you here some day bud.

Originally Posted by M_Chronos

Step 1: Remove POS JB4 you bought used
Step 2: Pray POS JB4 didn't destroy (in order) plugs, turbo, pistons
Step 3: Success

My eBay JB4 was fucked up too, and I sent it back for a refund then later got a notice from USPS saying that the seller had successfully claimed damage during shipping.... ¯\_(ツ)_/¯

OP, very unlikely that it hurt anything.

[pbonsalb]

I have run a JB4 on my 08 E61 535xi with the same N54 as the OP’s car for years. Probably not wired correctly. I apologize for the M snob behavior by some here.

[M_Chronos]

What some read as snob behavior was written as sound advice.

[Acoop]

Originally Posted by MBimmer2011

You're definitely in the wrong forum, but I had a 335i a long time ago with a JB4 and Procede. Did you ensure that all of your wiring is correct? If you don't have everything matched up properly, it will cause all kinds of havoc. Also, once you check your wiring, how many miles do you have on the spark plugs? I can assure you that if you have >20k miles on them you will get misfires and be in limp mode. Best of luck!

I checked the wiring and everything seems good. The spark plugs have a lot of miles on them, probably more then 20k. But how would this cause the car to not start up when it was running and driving perfectly before the install?

[Acoop]

Originally Posted by chocstraw

M-Snobs are phags.

Check the wiring, make sure everything is in right, make sure that the JB is flashed to the correct vehicle you have, etc. I had some issues getting mine setup too.

N54tech, E90post are better for this. Hope to see you here some day bud.



My eBay JB4 was fucked up too, and I sent it back for a refund then later got a notice from USPS saying that the seller had successfully claimed damage during shipping.... ¯\_(ツ)_/¯

OP, very unlikely that it hurt anything.

Sadly I bought it on the forums here, so pretty sure I can't return it.

[AC/DC]

Originally Posted by Acoop

I checked the wiring and everything seems good. The spark plugs have a lot of miles on them, probably more then 20k. But how would this cause the car to not start up when it was running and driving perfectly before the install?

I still think there's a wiring issue. I'd reach out to Burger Motorsports; they will let you ship your module to them for testing. I'd recommend fully removing the device, going back to stock, and shipping to them for repairs.

I personally did this years back because my fans were going crazy for no reason when I installed. I shipped back to them and they stated they found the problem and shipped my an upgraded unit that worked flawlessly, other than the occasional limp mode. Trust me, you'll want to replace the spark plugs; the extra boost will strain your plugs.

[pbonsalb]

And your original coils will begin causing misfires so you will want to replace them when that starts happening. I used S55 coils. If the car ran fine before the JB4 install, changing plugs won’t fix the no start issue. It’s probably a wiring issue.

[Acoop]

Originally Posted by MBimmer2011

I still think there's a wiring issue. I'd reach out to Burger Motorsports; they will let you ship your module to them for testing. I'd recommend fully removing the device, going back to stock, and shipping to them for repairs.

I personally did this years back because my fans were going crazy for no reason when I installed. I shipped back to them and they stated they found the problem and shipped my an upgraded unit that worked flawlessly, other than the occasional limp mode. Trust me, you'll want to replace the spark plugs; the extra boost will strain your plugs.

Ok will do. I have already bought plugs and everything was ready for the jb4 install. I was planning on installing the jb4 then plugs and coils, but that might be awhile away it seems.

[amrazM]

The harness for the jb4 isn’t install properly. Make sure the gray and black plugs are seated in the lowest position and not sticking out the top.