joeekrub

Quick Synopsis to see if I can narrow this down:

Has JB4 installed for a year

Car wouldnt start one day(continuously cranks, but wouldnt start)

Got it towed to BMW, for what I thought would be the HPFP, turns out they jiggled wires in the box in the engine bay(with ECU) and it started. They blamed it on the JB4 connections

Drove it home from the dealership, parked it, came out an hour later, same thing, cranks but wont start

I removed the JB4, still wont start


Jiggled all the wires, starts, but has 7 CEL codes, erased them, they dont come back

HERE IS THE INTERESTING PART:
After I got it started, I let it idle for 15 minutes, turned it off went back inside for 12 hours. Come out the next morning, keeping in mind it hasnt moved or been touched, and it WONT START.

I then go to work, come back and just for fun try and start it again, it fires right up


Thoughts?


Codes:
U0100
P0238
U0100 (pd)
P0171
P0301
P114A
P2196
P240A (pd)

zach1328

Wow - thats a lot of codes! I recognize P0301 as Cylinder 1 misfire because I just installed my JB4 a few weeks ago and I am getting that same code. Only P0301 though.

U0100 means lost connection with the ECM. I'll have to look at the rest and get back with what I find.

Did you have any codes before this started happening, or did all 7 come at the same time?

zach1328

This is a tough one. A lot of the codes lead me to believe its a faulty fuel injector or o2 sensor - or both. However, if those are both faulty you still shouldn't be getting U0100 which means you lost connection with you ECU.

This is most likely a combination of issues that is going to take some time to fix.
When I installed my Jb4 I accidentally left a loose connection on one of the sub-connectors which caused the car to have long crank times and gave a CE light.
Did you possibly bend or break a pin during install or uninstall? Is everything seated properly in your ECU? I would start with the ECU and make sure all connections are secure.

Its most likely ECU related as wiggling the wires helps it start right up. Since the ECU controls just about everything a loose connection can cause tons of other issues (not permanent).

For example, a simple loose sub-connector caused my car to not crank over and when I hit the lock button on my key everything turned on like the car had a mind of its own.
The radiator, water pump, radio, interior lights, headlights, blinkers etc all came on. Literally everything started going except for the engine all from hitting the lock button on my key. I was freaking out for a moment because I had never seen anything like that happen before - or even heard of it happening.

Anyways, if all connections in the ECU are secure (double check everything!) move on to the code P0301. This code will be very important for determining your issues.
A cylinder 1 misfire has 4 main causes and they are:
1) Faulty injector
2) Faulty spark plug
3) Faulty Coil Pack
4) Defective Computer

Here's what you need to do: Move the injector, spark plug, and ignition coil from cylinder #1 to cylinder #2. If the misfire moves to cylinder 2 your computer MIGHT be fine and you likely have a faulty injector, plug, or coil.
If you move those 3 things to Cylinder 2 and you still get code P0301 then I almost guarantee you have a faulty ECU.

Goodluck! If its not an improper connection, faulty ECU, or faulty o2 sensors/injectors then its back to square one.

zach1328

Any updates on what the issue was? Have you fixed it yet?

Ironically I'm now starting to have similar issues with similar codes. I haven't opened the ECU yet so idk if I have any loose connections, but I'm getting 7 of 9 of the same codes as you are.
I'm also getting U0001 which scares me because that is High Speed CAN Communication Bus issues. Basically my ECU is struggling to communicate with the rest of my car. Hopefully its just a loose connection with my JB4.