MS1 V2.2 RPM spike in boost

[m3ltd0wn]

Hello,

Need some help please with random high RPM spikes while in boost (feels like a missfire)
Car specs:
E30 BMW 2.5 inline 6 non vanos, t3/t4 turbo running at ~1bar, 38mm wastegate, VR6 coilpack , BKR7EIX spark plugs gapped at 0.55mm, Megasquirt 1 V2.2 Hr11d controlling fuel and spark, 440cc Bosch Hi-Z injectors, two bosch 044 fuel pumps, adjustable fuel pressure regulator, 5kohm beru spark plug wires, 60-2 trigger wheel with VW Hall sensor.

Car runs ok off boost, but once we go hard on the throttle the engine has a rpm spike at about 5000rpm; the rpm spike is random, it can happen on two consecutive runs and then it can disappear.
We did a couple of runs and made a log to see what the hell is happening, I'm over my head with this problem because I can't get to fix it no matter what I do and what I change, also there were days when the rpm signal was clear no rpm spikes no missfires, and days where all hell broke loose.
The MS is grounded at the engine block, it gets power from main battery wire through a relay and a fuse, all is verified and we have a solid ground.
We tried to shield out the engine harness in order to fix this rpm spike but no results yet.
These are the settings:

settings.jpg

Please find attached the log file:

2016-09-07_23.25.43.zip

Any suggestion is highly appreciated.
Thanks in advance.

[Matt Cramer]

Can you get a tooth log of the RPM spike?

[m3ltd0wn]

Tomorrow we will test the car again, and I will capture the log file and attach it.

[m3ltd0wn]

Hello,

Sorry for the delay, here are the latest data logs:

DataLogs.zip

Meanwhile we've changed the MS unit with another one (MS1 v2.2), we changed processors and firmware but the spike is still present, and now I can see a reset.


Best regards.

[Matt Cramer]

I am seeing a few noise pulses showing up - you may need to try something like a 10K resistor across the sensor.

[m3ltd0wn]

the problem was solved.
in the end we replaced the new spark plug wires with some old ones and now the car runs perfect.
it seems that the new beru spark plug wires were faulty (we changed 2 sets and with both the engine behaved badly on hard accelerations).

thanks all for the support!

[mac1]

I am seeing a few noise pulses showing up - you may need to try something like a 10K resistor across the sensor.

I'm running a Hall effect on a Hyundai 2.0L Beta, also ms1 ver 2.2 non-shielded but not exactly near any ignition wires.
I'm having RPM spikes just about anywhere when I Rev the motor. I've attatched a tooth log and trigger log and you can see it. Where would I place the 10k resistor? Across the signal and GND wires of the ckp sensor?

[slow_hemi6]

That kind of resistance is not really beneficial to the squarewave output you get from a hall sensor. A vr sensor produces a voltage that increases with rpm, that is why adding resistance can help a vr sensor.
You need to outline what kind of sensor and wheel arrangement you have and how it is connected to the megasquirt. What components make up the spark hardware and all oem crank/cam triggers I have seen are shielded so don't see that as optional.

[whittlebeast]

Look at SecL. You have a power or ground issue. Your battery voltage is also dropping at high RPM.