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Old 03-26-2016, 05:24 PM   #1
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Default Idle Valve Issues

Hey guys. I'm working getting my VVT swap running and this is the last major challenge I'm having before it will be running well. The engine is wired exactly as per the megathread, and I'm using a MS3x, and the NB throttle body/idle valve. The problem is weird because the idle valve was working fine last month when I got the engine started, but now it is completely unresponsive. It doesn't buzz when the ignition is on like it did (wrong frequency) and the car needs throttle to start (it does run idle on the screw once warmed up). I have a spare NB idle valve and when I plug it in, it doesn't do anything either. I've measured 12V to ground at the valve connector, but I'm not sure how to measure the signal wire (ecu switched ground), since I don't have an oscilloscope.

That leaves me thinking that it's either ECU software or hardware, or the connection between valve and ECU. I've visually checked the connections but haven't checked for continuity yet. The ECU shows expected PWM behavior on the gauge. I don't see anything in the settings that could be disabling output. I've changed lots of stuff in the process of tuning the car and I don't remember exactly what I changed before it quit. In fact, I think it quit working for a little while, then started working again, and now hasn't worked for a while. This is over the span of the last two months.

So, anyone have any ideas what could have gone wrong? Software? Hardware? Two bad valves? I'll attach my current tune as well.
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File Type: msq 1.8 3_26.msq (225.6 KB, 37 views)
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Old 03-27-2016, 05:32 PM   #2
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Update: bad solder joint on my breakout board. Redid it and the car is running really well. Not sure how that one slipped through QC
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