Car was running too perfect...I had a feeling it would not last.

[matreyia]

Situation: Morning, went for a drive - multiple WOT, multiple pulls, long and short durations in all driving modes. Car ran flawlessly.
Just a couple of hours ago...around 7pm... drove on highway, made a WOT pull in grandma mode from 70mph...car goes into check engine light and misfire on cylinder one.
Then it went away... so I parked and read the faults...nothing except for misfire cylinder one code.

Restart and drove home. When driving normal, accelerating conservatively, car is flawless...but any time I press the pedal semi firmly or firmly to accelerate quicker than normal...it goes into misfire cylinder one. Right before misfire, it shudders and shakes.

Specifications of Car:
new two step colder ngk plugs at .22
PR Coils
BMP billet manifold with port injection
AIC6
BPM4 EKPM UNIT UPGRADE
stage 3 lpfp Precision Raceworks
2 ccans
plugged ports
29psi
Pure stage 2 hiflows
relocated inlets
aluminum outlets PSP
Flex Fuel
full tank e85

Here is the log.

 

[matreyia]

Replaced the entire set of PR plug wires and misfire went away.
Now to figure out what the hissing sound is about...

 

[martymil]

I had my leads fail to this week ,changed all the spark plugs went for a drive and the car started misfiring, after countless hrs of trouble shooting found the problem and it was three faulty leads which where not pr ones, ended up digging out some old pr ones changed the misfiring cylinders all back to normal.

Ordered two new sets of leads.

The amount of heat these engines produce made my custom leads go hard and when I pulled them off using a special tool to prevent this from happening, it happened anyway.

Now I know why BMW went with pencil type coils, beginning to have a love & hate relationship with the N54.

 

[matreyia]

I had my leads fail to this week ,changed all the spark plugs went for a drive and the car started misfiring, after countless hrs of trouble shooting found the problem and it was three faulty leads which where not pr ones, ended up digging out some old pr ones changed the misfiring cylinders all back to normal.

Ordered two new sets of leads.

The amount of heat these engines produce made my custom leads go hard and when I pulled them off using a special tool to prevent this from happening, it happened anyway.

Now I know why BMW went with pencil type coils, beginning to have a love & hate relationship with the N54.

For my case, the blue silicone wire part had blackened parts in some areas. So I changed them. At first, misfires were on #1 so I checked plugs and they were brand new. So I switched wire 1 to #2 and misfire went away...so I replaced entire wire set and all is perfect now, even at WOT at any entry place on the throttle.

But... now I have see if I can seal the leak somewhere at the rear of the engine at the PCV area that may be causing the initial hiccup from full stop.

 

[fmorelli]

I had my leads fail to this week ,changed all the spark plugs went for a drive and the car started misfiring, after countless hrs of trouble shooting found the problem and it was three faulty leads which where not pr ones, ended up digging out some old pr ones changed the misfiring cylinders all back to normal.

Ordered two new sets of leads.

The amount of heat these engines produce made my custom leads go hard and when I pulled them off using a special tool to prevent this from happening, it happened anyway.

Now I know why BMW went with pencil type coils, beginning to have a love & hate relationship with the N54.

I believe there is a market for a pencil coil setup that is properly done - by that I mean, the pencils properly modified, the harness and electronics done to beyond hardware store specs. Aircraft grade, race grade, whatever you want to call it.

Sorry to hear about the problems but glad you solved it. Chasing these kinds of gremlins can be frustrating.

Filippo