Forum » General Tuning Discussion » Motec M130 Bad Pitch

Motec M130 Bad Pitch

General Tuning Discussion

Discuss all things tuning in this section. News, products, problems and results. 

Page 1

I am working on setting up a motor with an M130. I believe i have the correct offset and other parameters and have gotten the motor to run for a few minutes once. This is the first motor I have built a full harness for and started from scratch on the ecu with.

My first question is what does Bad Pitch on the Engine Synchronization mean? I cannot find a real answer to help trouble shoot this.

My second question is I get cycle lock the car attempts to fire then stops trying. Does it going into bad pitch prevent the car from starting? It is still in cycle lock the whole time.

Thanks in Advance.

Cycle Lock is required for fuel and spark to be delivered. So it won't run unless that condition is true.

Bad Pitch means that the tooth spacing is changing faster than the ECU thinks the engine can speed up/slow down. This can be caused by low cranking speed, high compression, etc. Do you get pitch errors if you crank with no spark plugs installed?

I was getting pitch errors when I was using a magnetic sensor and had selected the wrong active edge. I was able to work around it by fooling with the pitch thresholds (Wide Pitch = 190, and Narrow Pitch = 30%), but the right fix was to set the correct active edge. You should use the "Online->Capture Inputs" (requires M1 Tune 1.4 and recent firmware) to see what your Ref & Sync signals looks like.

David, Thank you for the response.

I have attached a few screenshots and the log file from a cranking session with the ignition on. Hoping that may clear up what I am seeing and what its doing.

Any suggestions are appreciated. Right now I am at that point of lack of experience, a lot of new terminology and a lot of input from others that dont know what is going on either :)

Thanks Again

Attached Files

Why don't you give me a call. We're in the same timezone, and we can talk about this -- I have some ideas. I see you can't do the capture inputs because you have much older firmware (1.02, current is I would start by biting the bullet and upgrading the firmware to the latest (yes, that will be a chore), then you will have other tools that can help you like capture inputs. Otherwise, can you connect a digital storage oscilloscope to the ref & sync and check the signal quality.

David Ferguson

Veracity Racing Data

Paso Robles, CA


[email protected]

Hi Plosey,

What engine are you using, it looks like it might be a engine with variable valve timing based in the cam pattern? Can you also tell me what the reference mode that you have selected is as a number of the crankshaft based modes will only accept a single sync tooth, and having multiple teeth (as your logging shows) will bring up errors. There may be a more suitable mode available for your engine that will work with the camshaft that you have.

The Bad Pitch error on the Sync that you are getting will be from the multiple teeth, as the M1 will be reading the missed teeth on the Reference, and then calculating based on the Reference Offset where to expect the next sync tooth edge, as it will see multiple and the reference mode has not been written to accommodate this, then it will give a Bad Pitch error (pitch being the calculated gap between teeth, if it moves outside the gate set in the mode, then you get a Bad Pitch error) This is also being shown up with the Hysteresis Noise error where the M1 is detecting a signal that is great enough to exceed the trigger voltage outside of where it is expecting a signal. You can see this in he logging where the Sync Voltage exceeds the Hysteresis value.

Are you able to post a short log of the engine cranking?

I've had a quick look through the logging and config, and the mode that has been used only supports a single sync tooth.

You have the ignition trigger on a rising edge, most ignition systems trigger on a falling edge, has the use of a rising edge been specified by the manufacturer of the ignition system?

There is a 0.6v offset on the sync pin, I can't see a reason for this in the logging as the sync signal floats around 0v

The Sync signal is quite noisy, this will cause issues at higher engine speeds as the noise will potentially exceed the hysteresis levels.

Can you change the default mapping for the Engine Run Switch to On.

Copying the Scale and Offset values from the Throttle Position Sensor into the Throttle Pedal and Throttle Servo Bank 1 Main and Tracking Scale and Offset parameters will get rid of a number of errors that you have.

The ECU Diagnostic values need to be changed from 0v low and 4.95v high.

You are also licensed for July 2015 GPR so you can download that from the MoTeCOnline website and install it onto your M1, this will allow you to use the Capture Outputs function and get a proper capture of the Ref and Sync.

Also, you should always make sure to run the updates in M1 tunes, as these also include new system files for the M1 as well.


Thanks to David and Black Rex for the help and info so far. We were able to get it running and will have it on the dyno next week to actually get it running correctly and hopefully give it a nice tune.

The Capture input tools is an amazing help in the new firmware and can tell you a lot vs the live or i2 data log. (attached screenshot)

The motor is a Custom BMW S54 (non vanos) with a modified trigger wheel with unequal spacing (Machined one going in next week) and our cam trigger has two bolts holding it on and the difference between the trigger and the bolts is just not enough (So modifying that for next week as well).

Attached Files