MartinS Posted September 18, 2023 Report Share Posted September 18, 2023 Hi, just did some engine work, didn't change wiring, sensors, or tune. First start this morning, just did a fast idle warm up to bleed cooling system and look for problems. Started and ran beautifully. Let it cool, topped up coolant and oil and went for first drive. Started and idled beautifully, ran great, drove about 3 city blocks (got into second gear at about 30km/hr in residential neighbourhood with no issues) and engine suddenly started bucking and stalled. Pulled over, restarted and limped into alley to get back to garage running rough, bucking, and stalling several times. Had to get a push the last 50 meters as it wouldn't restart. I've gone through the log and I'm getting trigger errors. Looks like it's getting trigger signal from both triggers 1 and 2 fine but the errors are accumulating. Any help would be greatly appreciated. Log and PCL file links below... Thanks in advance. https://drive.google.com/file/d/1xJivnJykC_JkZGq5Noos6q3W4uEY0XD_/view?usp=sharing https://drive.google.com/file/d/1EM-0DJje_vF70rCYjQ6sDDIlO5qwsx5C/view?usp=share_link Quote Link to comment Share on other sites More sharing options...
David Ferguson Posted September 18, 2023 Report Share Posted September 18, 2023 3 blocks -- about the time it takes for a sensor only hand tight to loosen up. Or perhaps the trigger wheel mounting is loose. Careful inspection is required. Also, make sure there aren't any wires rubbing on a belt or something. Quote Link to comment Share on other sites More sharing options...
MartinS Posted September 18, 2023 Author Report Share Posted September 18, 2023 Good points. Inspection and. oscilloscope first thing in the morning... Quote Link to comment Share on other sites More sharing options...
MartinS Posted September 19, 2023 Author Report Share Posted September 19, 2023 Inspected trigger wiring this morning, nothing out of the ordinary found physically with wiring. Tried to start: ran so-so at idle for a few seconds then died. Further cranking: no start. Attached links to 3 pics of the oscilloscope screen of triggers. Signal taken off wiring as it enters ECU. After experience trouble shooting previous issue with crank trigger, that tracing looks ok to me. The cam trigger looks off to me but I can't quite figure it out. Offset seems too big? I apologize I was not able to get the settings just right on the tracings but by the time I'd fiddled with the scope to get both signals on the screen and approaching readable, my battery was out of juice. Thought I'd post these while I recharged it hoping for advise on best settings for that channel as oscilloscopes are way out of my wheelhouse. Thanks. https://drive.google.com/file/d/16tpU_tWQYVsv2obo6avEAIZEioCG78pj/view?usp=share_link https://drive.google.com/file/d/1rN3L-u8HDeGGPwjn3QoKypmcjS21k3cY/view?usp=share_link https://drive.google.com/file/d/1klTQoJSiexdCuqc12v8bt-gVY-b1GKe_/view?usp=share_link Quote Link to comment Share on other sites More sharing options...
David Ferguson Posted September 19, 2023 Report Share Posted September 19, 2023 The cam trigger looks like it struggles to reach ground. Is that an OEM sensor, or some other type of trigger setup off the cam or distributor? Quote Link to comment Share on other sites More sharing options...
MartinS Posted September 19, 2023 Author Report Share Posted September 19, 2023 Original to engine. Could signal and 12v lines be reversed? Ground is correct. Quote Link to comment Share on other sites More sharing options...
MartinS Posted September 19, 2023 Author Report Share Posted September 19, 2023 Just pulled cam pos sensor, wired correctly as per engine manual. Tested against 4 known good sensors: same resistances between pins. Quote Link to comment Share on other sites More sharing options...
MartinS Posted September 19, 2023 Author Report Share Posted September 19, 2023 Looking at the log file more closely, while there are trigger 2 errors accumulating when the engine is running, trigger 1 errors are accumulating at a much faster rate. Assessing the crank trigger, no issues found with physical setup. I am unable to find enough information in the 'Help' files understand what is happening and why. Any help appreciated. Quote Link to comment Share on other sites More sharing options...
Adamw Posted September 20, 2023 Report Share Posted September 20, 2023 It is your cam signal that is the problem, as David suggests, it is not driving to ground. The little yellow arrow on the left of the screen is 0V or ground, the signal from a hall sensor should get very close to that when exposed to a tooth. The sensor is effectively a switch that just shorts the signal wire to ground when a tooth is in front of the sensor. So your signal should look more like below: So it appears you have a compromised ground to the cam sensor. Start by confirming you have good continuity from the ground pin at the sensor plug back to the ECU pin A7. Make sure the contact in the cam sensor plug still has good spring tension on the terminal etc. You can probably pull the sensor out and just place metal in front of it for testing instead of running or trying to run the engine. You should see something above about 4V with nothing in front of it and less than say 0.3V when metal is in front of it. Quote Link to comment Share on other sites More sharing options...
MartinS Posted September 21, 2023 Author Report Share Posted September 21, 2023 Ok, thanks for the help! Cleaned, checked, and tested sensor plug. All good. I then focussed on the ground and decided to wire it and signal directly from the sensor plug to the Link wiring loom bypassing the engine wiring loom and the Subaru engine plug and socket. Once done, I powered up the system and the scope still showed a nearly +5V offset in the Trigger 2 signal. After a few minutes wondering what to do next, I decided I'd change the plug anyway and see if some kind of epiphany would come to me in the meantime. Changed it, plugged in, turned on: Trigger 2 scope tracing at zero! Put it all back together, started and ran great. So much for my plug inspection... Thanks again! Quote Link to comment Share on other sites More sharing options...
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