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LTC & LTCN

PostPosted: Thu Jan 16, 2025 10:45 am
by Exigeman
Hello
We were chasing Fuel closed Loop errors every now and then, suddenly there would be a bad reading.
Thought was this was caused by a bad sensor.
What I have found is that the LTC type setting was for LTC while we are using an NTK sensor and LTCN module.
I have changed now the setup to reflect that .. errors have not changed so far.
What issues would the wrong module setup have created ?
Thanks ..

Re: LTC & LTCN

PostPosted: Thu Jan 16, 2025 11:11 am
by David Ferguson
I don't think you've caused any issues by having the LTC mis-identified.

Can you provide a better description of the "Fuel Closed Loop errors" -- maybe provide a logged data example that shows what you are seeing, including the "bad readings".

What firmware package are you using?
What is the value of the Fuel Closed Loop Fault Delay parameter?
What are the values of the Fuel Closed Loop Control Trim Min & Max?

If these are too small, and the Delay Parameter is too small, the Fuel Closed Loop system will stop working .

Re: LTC & LTCN

PostPosted: Thu Jan 16, 2025 11:57 am
by Exigeman
Hello David
Many thanks for reply
Attached a log file
What firmware package are you using? - 01.11.0099
What is the value of the Fuel Closed Loop Fault Delay parameter? - 65.0s
What are the values of the Fuel Closed Loop Control Trim Min & Max? Min -10% Max 10%

Thanks
Andrew

Re: LTC & LTCN

PostPosted: Thu Jan 16, 2025 12:25 pm
by David Ferguson
It looks like your fueling is off quite a bit -- I would suggest you fix the fueling (Engine Efficiency table), but you could get closer by giving your Fuel Closed Loop Control Trim more authority (say -40 to +40).

- At the 20 minute mark, engine is idling at 1750 RPM, Fuel Mixture Aim is 0.93, but the Lambda is reading about .72 (so 30 % rich) if the Fuel Closed Loop is active, this it is probably removing 10% of the fuel just to get here.

If this is the first time you've run this engine, you probably need to review all the sensor inputs to make sure you've got valid values -- Inlet Air Temp looks ok at 12 - 26c. You had an Inlet Manifold Pressure reading up until the 20 minute mark -- but it looks very low (<25 kPa) - are you sure that sensor is calibrated correctly -- Does the value of Inlet Manifold Pressure Sensor seem correct when the engine is stopped (should read close to ambient pressure).

Since the fueling is so far off, I wonder if you've selected the correct fuel properties, and fuel injectors.

Re: LTC & LTCN

PostPosted: Thu Jan 16, 2025 12:48 pm
by Exigeman
Thanks David, thats spot on about the fuelling .. its rich for sure, fuel and injectors are correct.
Will check that pressure sensor - its in the airbox, this is a NA engine on Throttle bodies - should be around 100Kpa ambient here.

Re: LTC & LTCN

PostPosted: Thu Jan 16, 2025 1:49 pm
by Stephen Dean
Have you looked through the Multi Throttle Tuning Guide?

There are some changes to how the M1 is configured to run based off of TPS, rather than MAP.

Re: LTC & LTCN

PostPosted: Thu Jan 16, 2025 2:18 pm
by Exigeman
Thanks Stephen & David
Yup, thats how its set up - the Pressure sensor is measuring from the airbox and I checked its around at 96 Kpa with engine stopped.
However checking through the setup again I see Injector location is set to After throttle .. I guess this will make some difference ... ??
Will change it to Before Throttle Airbox referenced.