SimonR32 Posted March 7, 2018 Report Share Posted March 7, 2018 Hi guys, Got a few little niggling issues, first is the speed sensor. Have set at rising and falling and tried to calibrate but it seems to jump around all over the place. I did have a Vipec plug in before this and it worked perfectly and then started playing up after the swap and appears to get worse and worse. Had a few different gearboxes in as well so I don't think it's the sensor. Settings and logs in images. I also have a little issue with the high octane crank trigger kit. The signal appears to "bounce" a little when the throttle is released, probably not the biggest issue but it does make the data for the flat shift cuts for the sequential box tuning a lot harder. Example highlighted in red circles Quote Link to comment Share on other sites More sharing options...
Adamw Posted March 7, 2018 Report Share Posted March 7, 2018 You need the DI pull-up resistor turned on for the skyline VSS as far as I know. Do you reckon that "bounce" in the RPM could be caused by say the drive dog backlash or something else in the driveline? It could be trigger as you suspect but its just wierd that it seems to be associated with over-run conditions, I cant quite make the logical link between the trigger and over-run... Having said that, I had never heard of the "High Octane trigger kit" so just googled it, there is potentially a problem with it depending on how accurately their picture matches the actual kit you got. Their picture shows it is using a ZF/Cherry GS1005 sensor but it doesnt look like they have wired in the extra pull-up resistor these sensors require. These sensors get lazy without the manufacturer recommended pull-up. So can you confirm: Is the crank sensor a GS1005 (usually identifiable as red aluminium body with M12 thread)? Does it have a pull-up resistor in the wiring or connector etc? (maybe under heat shrink etc)? Is it powered by 12V? MagicMike 1 Quote Link to comment Share on other sites More sharing options...
MagicMike Posted March 7, 2018 Report Share Posted March 7, 2018 Something I have NOT done with my sensor. Will do ASAP tho... Hang on, what about the ECU pullup? Mine is already set to 'ON' Quote Link to comment Share on other sites More sharing options...
Adamw Posted March 7, 2018 Report Share Posted March 7, 2018 ECU built in trigger pull up is 4.7K, so not strong enough for what the GS1005 wants. MagicMike 1 Quote Link to comment Share on other sites More sharing options...
MagicMike Posted March 7, 2018 Report Share Posted March 7, 2018 15 hours ago, Adamw said: ECU built in trigger pull up is 4.7K, so not strong enough for what the GS1005 wants. How big is the ECU pull-up? Quote Link to comment Share on other sites More sharing options...
SimonR32 Posted March 8, 2018 Author Report Share Posted March 8, 2018 Thanks for the reply, speed seems to have fixed with the pull up resistor on (although does still have some random low spikes) but I may try and switch the falling edge tonight but it's a massive improvement. I'll look into wiring a resistor into the sensor and see how I go, sounds like a bigger job but may be worth it Quote Link to comment Share on other sites More sharing options...
Adamw Posted March 8, 2018 Report Share Posted March 8, 2018 2 hours ago, MagicMike said: How big is the ECU pull-up? Huh? That is in the reply of mine that you quoted. To make it clearer, the built-in pull-up on the trigger inputs (when turned on) is 4.7K to 5V. Quote Link to comment Share on other sites More sharing options...
MagicMike Posted March 8, 2018 Report Share Posted March 8, 2018 27 minutes ago, Adamw said: Huh? That is in the reply of mine that you quoted. To make it clearer, the built-in pull-up on the trigger inputs (when turned on) is 4.7K to 5V. Brain fail, sorry mate Quote Link to comment Share on other sites More sharing options...
mapper Posted March 10, 2018 Report Share Posted March 10, 2018 Do I miss something? ECU has built-in Trigger Pullup of 4.7kOhms. GS1005 Sensor is asking for a 2.4kOhm pullup Resistor to 12V. The ECU pull-up is already higher than the recommended one. Why should we use the second pull-up? And how can Cherry/ZF recommend a pull-up resistor without knowing what pull-up is in the ECU? Quote Link to comment Share on other sites More sharing options...
Adamw Posted March 10, 2018 Report Share Posted March 10, 2018 12 minutes ago, mapper said: Do I miss something? ECU has built-in Trigger Pullup of 4.7kOhms. GS1005 Sensor is asking for a 2.4kOhm pullup Resistor to 12V. The ECU pull-up is already higher than the recommended one. Higher resistance is less pull-up effect, the sensor needs a stronger pull-up (lower resistance) to switch cleanly. The ecu pull up (when turned on) is 4.7k ohm to 5v. ZF recommends 1kohm if connected to 5v, that is approx 5 times “stronger” than what the ecu can provide. Their recommended values would be based on the interface circuit having no pull-up. In this case, assuming the user is powering from 12V, it would be easiest to turn off the ecu pull-up and just add a 2.4K external between the 12v and signal wires Quote Link to comment Share on other sites More sharing options...
mapper Posted March 10, 2018 Report Share Posted March 10, 2018 well no it's clear, thank you Adam. Quote Link to comment Share on other sites More sharing options...
SimonR32 Posted March 12, 2018 Author Report Share Posted March 12, 2018 On 10/03/2018 at 6:16 PM, Adamw said: Higher resistance is less pull-up effect, the sensor needs a stronger pull-up (lower resistance) to switch cleanly. The ecu pull up (when turned on) is 4.7k ohm to 5v. ZF recommends 1kohm if connected to 5v, that is approx 5 times “stronger” than what the ecu can provide. Their recommended values would be based on the interface circuit having no pull-up. In this case, assuming the user is powering from 12V, it would be easiest to turn off the ecu pull-up and just add a 2.4K external between the 12v and signal wires Is it just my imagination or could these be correlated? Quote Link to comment Share on other sites More sharing options...
Adamw Posted March 13, 2018 Report Share Posted March 13, 2018 I would say that most of it could be explained by real data, but there is enough coincidence there that I would be taking a closer look at other data to confirm. My first suggestion would be to add Batt voltage, 12V internal and the 5V out parameters to your time plot and see if any of those show any interaction in the same areas. Quote Link to comment Share on other sites More sharing options...
SimonR32 Posted March 13, 2018 Author Report Share Posted March 13, 2018 5V out is rock solid on 4.99V 12V internal does occasionally drop to 11.7V from 12.01 but nothing to correlate to the rpm or speed jumping around, same with the battery. Redid some more testing and it doesn't appear that the speed and rpm wobble are related, just seems to happen more often together but not all the time. Wierd Quote Link to comment Share on other sites More sharing options...
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