Troubleshooting Recently Lost TPS Signal (Inside The Case)
Posted: Fri Nov 10, 2017 2:20 pm
This is for a home-built MS3+MS3X on a V3.0 board that was running full-sequential fuel, spark and IAC on a '97 BMW 540i with an M62b44 engine, very nicely for several days until the following occurred.
Long story short: I was driving home from the drag strip two nights ago, when I started to roll into boost on the entrance ramp to the freeway. It felt like I hit a boost cut -- way earlier than should have been possible -- but then the engine just would not come back to life. I coasted to the shoulder and the engine would crank like mad, but would not restart. My laptop had died at the track, so I couldn't troubleshoot on site.
After 20 minutes or so I randomly cranked the engine, and it started so I drove the 95 miles home. Last night I went out for a drive to try and replicate the problem, and the only thing I found to be wrong was no TPS signal showing up in TunerStudio, I could not replicate the problem. Today I started chasing the lack of TPS, and found that I have proper TPS voltage from the throttle body all the way to the main connector pin22.
Looking inside the case, I see no problems on the solder joints from the connector to the main board, R9, C9, or C8... At this point I kind of don't know what to check next. Any assistance would be appreciated!
I'm not sure they can really help with this, but an .MSQ link is:
https://drive.google.com/open?id=1h_WvG ... pXyMkte-SJ
and here's a log from last night that shows the constant zero TPS:
https://drive.google.com/open?id=1ulRc5 ... fn9EesBRM0
Thanks,
Thad
Long story short: I was driving home from the drag strip two nights ago, when I started to roll into boost on the entrance ramp to the freeway. It felt like I hit a boost cut -- way earlier than should have been possible -- but then the engine just would not come back to life. I coasted to the shoulder and the engine would crank like mad, but would not restart. My laptop had died at the track, so I couldn't troubleshoot on site.
After 20 minutes or so I randomly cranked the engine, and it started so I drove the 95 miles home. Last night I went out for a drive to try and replicate the problem, and the only thing I found to be wrong was no TPS signal showing up in TunerStudio, I could not replicate the problem. Today I started chasing the lack of TPS, and found that I have proper TPS voltage from the throttle body all the way to the main connector pin22.
Looking inside the case, I see no problems on the solder joints from the connector to the main board, R9, C9, or C8... At this point I kind of don't know what to check next. Any assistance would be appreciated!
I'm not sure they can really help with this, but an .MSQ link is:
https://drive.google.com/open?id=1h_WvG ... pXyMkte-SJ
and here's a log from last night that shows the constant zero TPS:
https://drive.google.com/open?id=1ulRc5 ... fn9EesBRM0
Thanks,
Thad