[SlowMsport]

Hello all! I have a 2016 340i Msport. JB4 and BMS intake installed. I pulled the spark plugs to check the gap and I did not disconnect the battery. After putting everything back together the car will crank but will not fire. I pulled cyl 1 plug and checked for spark during cranking. I then retraced my steps and checked all electrical connections and grounds. Everything looked good.

I still have no spark. I can smell fuel but the spark plugs are not getting power.

I have searched high and low, pulled every single fuse (to check) as I could not find a specific diagram for the fuses other than the one in the trunk.

I pulled the JB4 out and the vehicle is on the way to the dealer, So I will let every one know of what the outcome is if anyone has experienced this issue and could not find a resolution.

Is there a specific fuse for the ignition coils?

[Billfitz]

It's not necessary to disconnect the battery when changing plugs, so whatever the problem is it's not related to that.

[SlowMsport]

Originally Posted by Billfitz

It's not necessary to disconnect the battery when changing plugs, so whatever the problem is it's not related to that.

In removing the strut tower tie could I have grounded something? I cant figure out what I did wrong.

[Eschmacher]

If you moved the positive tie by the strut tower while the battery was connected you could have shorted something. I would check over all fuses. There's also a small chance your DME could have been damaged, but I'm not confident on that.

[SlowMsport]

Originally Posted by Eschmacher

If you moved the positive tie by the strut tower while the battery was connected you could have shorted something. I would check over all fuses. There's also a small chance your DME could have been damaged, but I'm not confident on that.

Luckily it is under warranty.

Latest update is they are reprogramming the vehicle over night.

I will have more info in the morning.

I am disappointed I couldn't figure this one out.

I will post the solution once it is known.

[SlowMsport]

Originally Posted by Billfitz

It's not necessary to disconnect the battery when changing plugs, so whatever the problem is it's not related to that.

That was what I was thinking but couldn't confirm. I did remove the coils completely but ensured they were numbered and went back into the original cylinder.

[bellguy]

Think the camshaft position sensor is near one of the coils towards the front on the B58, is it possible it got disconnected or the multiplug damaged, no spark if that's the case.
Just a thought.

[Eschmacher]

Originally Posted by SlowMsport

That was what I was thinking but couldn't confirm. I did remove the coils completely but ensured they were numbered and went back into the original cylinder.

Any update with this? Very curious what the issue is.

[SlowMsport]

Originally Posted by Eschmacher

Any update with this? Very curious what the issue is.

Just got the car back. I have no idea what the resolution was.

The dealer reprogrammed the car over night, put new plugs in it, and still had a crank no start issue.

I was then informed by the dealer that it was suspected that diesel was in the gas tank. I got my last fuel receipt and showed them that I did indeed put 93 in it (13.5 gal). At this point, I showed up at the dealer. They showed me the vehicle fired up with brake cleaner. I asked them if we had fuel pressure and we then verified spark. I asked them to put the car back together so we could see if it started, it fired right up. They kept it for a few hours to let it sit and test drive it. I picked it up at the end of the day.

I have driven the vehicle through one full tank of gas and have had no issues. The dealer also doesn't know what happened. To their credit, they wanted to know just as badly as I did.

The only thing I can assume is reprograming the car fixed it.

They did do a ton of diag, even checked compression and did a leak down test. The car passed with flying colors so at least I have brand new plugs and I know my motor is healthy.

Sorry I didn't have a definitive answer on this one. I will scan and post the dealer comments in a following post. I still wish I knew what would cause the car to not have spark but have fuel pressure.

[mfran615]

Glad you got it sorted out. Does having a tune not affect warranty issues at all?

[thejeremyman9]

Originally Posted by mfran615

Glad you got it sorted out. Does having a tune not affect warranty issues at all?

Depends first on if its something directly impacted by the tune (e.g., drivetrain). If not, tune should have no effect.

Then depends on the dealer and the magnitude of the repair (typically in $). If minor, they probably wont investigate. If major (engine, transmission, etc), BMW will probably be notified and tune can be detected and a means to deny warranty claim.

[cfm56d7b]

Originally Posted by SlowMsport

Just got the car back. I have no idea what the resolution was.

The dealer reprogrammed the car over night, put new plugs in it, and still had a crank no start issue.

I was then informed by the dealer that it was suspected that diesel was in the gas tank. I got my last fuel receipt and showed them that I did indeed put 93 in it (13.5 gal). At this point, I showed up at the dealer. They showed me the vehicle fired up with brake cleaner. I asked them if we had fuel pressure and we then verified spark. I asked them to put the car back together so we could see if it started, it fired right up. They kept it for a few hours to let it sit and test drive it. I picked it up at the end of the day.

I have driven the vehicle through one full tank of gas and have had no issues. The dealer also doesn't know what happened. To their credit, they wanted to know just as badly as I did.

The only thing I can assume is reprograming the car fixed it.

They did do a ton of diag, even checked compression and did a leak down test. The car passed with flying colors so at least I have brand new plugs and I know my motor is healthy.

Sorry I didn't have a definitive answer on this one. I will scan and post the dealer comments in a following post. I still wish I knew what would cause the car to not have spark but have fuel pressure.

Thanks for sharing and posting dealer comments. These mysteries are not helpful. Hope it will be a one time event.