Motec M1- Narrow pitch threshold

M1 package and logged data here:

Motec Logs & firmware

Vehicle and System Specifications

Engine: 2JZ 3.4L (94mm crankshaft, 9.1 CR, 3314.38 cc – (86.5×94×6)

Billet main caps, Manley Tri-beam rods, Diamond pistons

GSC Beehive springs, pocket port, shimless buckets, Tomei 264 cams (9.5 mm lift)

Precision 6466 Gen 2 turbocharger (.87 A/R), PHR S45 twin scroll manifold, 4” downpipe

Precision wastegates

FIC 1440cc injectors (14 mm, 64 mm length)

Aeromotive A1000 FPR, dual Walbro fuel pumps

Bosch DBW (0 280 750 473.1.0)

Motec LTC with Bosch 4.9 wideband sensor

150 PSI fuel and oil pressure sensors

Crank sensor 12x tooth , it has two cam sensors (single tooth pickup)

One cam sensor retained on my car and one is blocked off

you will notice the cam sensors are not used (inlet or Exhaust), the engine only runs the crank sensor only

Reading up , this is normal, simpler, robust, and standard practice for 2JZ-GTE (non-VVT)

Test OE Crank Sensor

The ”Cold” and ”Hot” . ”Cold” is from –10°C (14°F) to 50°C (122°F) and ”Hot” is from 50°C (122°F) to 100°C (212°F).

Cold Crankshaft Position Sensor : NIPPONDENSO 835–1,400 Ω and AISAN 985–1,600 Ω

Hot Crankshaft Position Sensor : NIPPONDENSO 1,060–1,645 Ω AISAN 1,265–1,890 Ω

OE Sensor reads -- Cold is 1302, I couldn't check if it was a sensor or aisan but it falls within spec

Ground , looks ok

Sensor AC voltage, would have to remove to test

Condition of plugs and pins look good

Observations

The vehicle is currently fitted with FIC 1440cc injectors; however, the ECU is operating with the pre-calibrated/characterised FIC 1000cc configuration.( I have updated the injector linerisation)

Data logs compared with dyno runs show lean spikes at high load and excessively rich conditions at light load. This raises concerns regarding potential fuel contamination, bore wash, idle instability, and misfires. I assume due to running 1440cc injector as a 1000cc injector

What I need help with

Warning -- Engine speed ref diag -- Noise

Noise

The reference input detected a tooth pitch below Narrow Pitch Threshold, indicating an edge has been missed or reference is not correctly locked to the pattern. The input falls back to searching for alignment with the reference pattern.

Looking at the Narrow pitch Threshold

Overview

It uses the default of 50% ,

The documentation below recommends 60%, reading online, setting the threshold to 60% resolved the issue

From my comprehension, A trigger wheel with a lower tooth count is more susceptible to this fault ( mine is a 12 tooth)

Documentation

Eng Speed Ref Narrow Pitch Thresh

Used to detect lock (and loss of lock) with the Reference pattern:

State is Search: The relative Tooth Pitch must exceed this value for State to change to Pattern Lock.

State is Pattern Lock or Cycle Lock: If the relative Tooth Pitch is less than this value Diagnostic is set to Noise and State is changed to Search.

image.pngGreyed area shows 50% of relative tooth pitch.

Suggest 60%, ie pitch may be up to 40% narrower to allow for engine acceleration.

NOTE: set Narrow Pitch Threshold = 100% Wide Pitch Threshold = 100% and analyse the value of Tooth Pitch during cranking to determine suitable values for these settings. There will be only one place in the pattern where Tooth Pitch is close to 100% and the thresholds must be set as close to 100% as practical to reject all other values, while maintaining Cycle Lock when the engine is running normally.

Motec Ref Sync

Looking at this webinair and going back to Narrow pitch Threshold , states not to touch the 3 settings (unless explicitly told) , wide, narrow pitch and blank ratio ; in future firmware updates , they will most likely be hidden

I am a bit confused , if setting Narrow pitch to 60% from 50% is correct

Looking here , they changed to 60% , fixed similar issue

https://www.hpacademy.com/forum/motec-m1-software-tutorial/show/invalid-narrow-pitch-threshold-message-for-engine-speed-channels/

Every setting in the ECU for a magnetic VR crank sensor within the Ref Sync looks spot on based on the webinar

Only thing I would like to check is the Engine Speed Reference Offset value as per ShaneT video , Motec forum , 390 degree mark is correct for a 2jzgte non vvti but Motec cannot provide a definitive offset value

392 is the value set on my car

[url=https://forum.motec.com.au/viewtopic.php?f=53&t=5591&p=26667]https://forum.motec.com.au/viewtopic.php?f=53&t=5591&p=26667

I do not have a validated number for this with the 12 tooth trigger, looking through the non VVTi Packages that I have access to shows a value around the 390° mark as a starting point.

Any help appreciated, should I alter the Narrow pitch thresholds?

Sensors

My Observations

• OE Coil dwell time these need to be verified the settings are correct
• Ignition driver current is set to 40 mA (Max value -- range 0 -40 mA) , Typically its 20 mA
• Engine Speed Reference Offset -- it is worth checking with a timing gun & CRIP Test
• Eng Speed Ref Narrow Pitch Thresh is set to 50 , Motec Documentation suggests 60% -- Warning below is intermittently triggered
• • Crank sensor was tested , its within spec 1302 ohms cold
  • Motec webinair says to leave these settings alone

Noise

The reference input detected a tooth pitch below Narrow Pitch Threshold, indicating an edge has been missed or reference is not correctly locked to the pattern. The input falls back to searching for alignment with the reference pattern.

Ignition driver current consequence of a high value is Electrical noise -- High current switching Sensor instability, communication errors might be the noise we are seeing, in addition the high mA can damage the ECU

Maybe setting the Ignition driver current to 20 mA and leaving the Eng Speed Ref Narrow Pitch Thresh at 50% is the answer