Throttle pot readings on Rovergauge
Discussion
Have poor idle and running issues, engine sounds uneven like running rich or misfiring.
Connected RG and found 2 fault codes: 17 & 19 (from memory these are - throttle pot and throttle pot lo, MAF hi)
Running the engine shows lambdas showing very -ve values, with the odd bank regularly hitting -100%. Seemingly confirms rich running.
I stopped engine, cleared the codes and watched the throttle position reading (absolute) on RG as I gradually opened the throttle and saw the full range of readings up to 100% with no apparent gaps. All other sensor readings seem reasonable.
I then took the car for a short run and after some really rough running (again sounding like misfiring/running very rich), the engine sounded better.
Put RG back on and saw the throttle pot reading now only rising to 85% at full throttle and at lower openings, the throttle pot reading (corrected) stayed near constant or rose very slowly at around 8-12% even though gradually opening the throttle.
I disconnected the throtte pot and reconnected several times in case it was poor connection, now readings go to 100% OK.
Question is how to tell if this is a faulty TPS or just poor connection.
Have heard that you can get open circuit track failures on TPS but don't get how it can stay near constant and if this can cause rich running.
Cheers for any comments / suggestions.
Connected RG and found 2 fault codes: 17 & 19 (from memory these are - throttle pot and throttle pot lo, MAF hi)
Running the engine shows lambdas showing very -ve values, with the odd bank regularly hitting -100%. Seemingly confirms rich running.
I stopped engine, cleared the codes and watched the throttle position reading (absolute) on RG as I gradually opened the throttle and saw the full range of readings up to 100% with no apparent gaps. All other sensor readings seem reasonable.
I then took the car for a short run and after some really rough running (again sounding like misfiring/running very rich), the engine sounded better.
Put RG back on and saw the throttle pot reading now only rising to 85% at full throttle and at lower openings, the throttle pot reading (corrected) stayed near constant or rose very slowly at around 8-12% even though gradually opening the throttle.
I disconnected the throtte pot and reconnected several times in case it was poor connection, now readings go to 100% OK.
Question is how to tell if this is a faulty TPS or just poor connection.
Have heard that you can get open circuit track failures on TPS but don't get how it can stay near constant and if this can cause rich running.
Cheers for any comments / suggestions.
Use the logging facility- turn on MAF, TP and RPM only and go for a drive. The log files are not that easy to read directly- you need to mess about in excel to get the cells to space correctly, but you will be able to spot drop outs in the TPS, against RPM and airflow. You can send me the log file if you wish.
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