zwhitebread Posted February 3, 2021 Report Share Posted February 3, 2021 I have been having an issue where my ecu is receiving extra cam pulses. Its on a link fury G4+ running a Subaru EZ36. I have replaced the sensors and i am still having the problem. I have shielded wiring running from the link to the sensor. It seems to mainly happen on the RH inlet sensor but occasionally happens on the LH inlet sensor. I have attached a short log that has an example of what is happening. Let me know if there is anything I can try or that I should look for to get this problem resolved. Thanks 2-3-2021 test.llg Quote Link to comment Share on other sites More sharing options...
Adamw Posted February 3, 2021 Report Share Posted February 3, 2021 Can you attach your tune and a trigger scope. Quote Link to comment Share on other sites More sharing options...
zwhitebread Posted February 4, 2021 Author Report Share Posted February 4, 2021 The trigger scope is at idle Trigger Scope 2021-02-3.llg ZachW _EZ36_sti_Test 02-03-2021.pclr Quote Link to comment Share on other sites More sharing options...
Adamw Posted February 4, 2021 Report Share Posted February 4, 2021 Can you do me another trigger scope at about 3000rpm. Your cam sensor signal is inverted compared to our simulated EZ36 pattern, which could potentially push the falling edge beyond the range it was designed to work in. But I do know some other subaru cam sensors flip polarities just above idle speed so want to confirm if yours does or not before I make a suggestion. Im not confident this is your issue but it is the only think that jumps out so far. Does it always happen at about 6000RPM? Only under load or can you cause it with just a free rev? Also, not related, but suggest you update to the latest firmware, you have the weird CLL spike in that log which was fixed in the later firmware. Quote Link to comment Share on other sites More sharing options...
zwhitebread Posted February 4, 2021 Author Report Share Posted February 4, 2021 Ok. I just updated the firmware. It seems to do it only under load. Here is a trigger scope for 3k Trigger Scope Log 2021-02-3 3k.llg Quote Link to comment Share on other sites More sharing options...
Adamw Posted February 4, 2021 Report Share Posted February 4, 2021 I dont think it is the issue, but as a process of elimination, can you try swapping to rising edge on trig 2 and DI3. You will have to do the cam angle test to set the offsets again on those 2 cams afterwards. Quote Link to comment Share on other sites More sharing options...
zwhitebread Posted February 4, 2021 Author Report Share Posted February 4, 2021 Will I need to set the base timing again if I change trig 2 from falling to rising? Quote Link to comment Share on other sites More sharing options...
Adamw Posted February 4, 2021 Report Share Posted February 4, 2021 If it doesnt start you will have to change the trigger offset by 360, but provided it still starts after the edge change then no need to do base timing again. Quote Link to comment Share on other sites More sharing options...
zwhitebread Posted February 5, 2021 Author Report Share Posted February 5, 2021 So I changed the Trig 2 and DI3 to Rising and did the Cam angle test. I haven't had a chance to test drive it yet, but it seems to start really hard now. Once it is running it is fine, it just takes alot of cranking to get it to start. Any idea what would cause this? Quote Link to comment Share on other sites More sharing options...
zwhitebread Posted February 6, 2021 Author Report Share Posted February 6, 2021 So I tested the car and I am still getting trigger errors. I only got errors on the RH inlet sensor. I can upload a short log if needed. Is there anything else I can try? Quote Link to comment Share on other sites More sharing options...
zwhitebread Posted February 9, 2021 Author Report Share Posted February 9, 2021 Is it possible that it is filtering issues? Quote Link to comment Share on other sites More sharing options...
Adamw Posted February 9, 2021 Report Share Posted February 9, 2021 I think the only way you are going to get to the bottom of it is to get someone with a standalone scope to connect to that cam sensor and monitor the waveform when the error occurs. Possibly a spike of electrical noise or similar causing the ecu to see an extra tooth where it isnt expected. Quote Link to comment Share on other sites More sharing options...
zwhitebread Posted February 12, 2021 Author Report Share Posted February 12, 2021 So here is a picture from an oscilloscope. It’s taking a readying from the RH inlet sensor. Let me know if you need/want anything specific 2021-02-11-14-52-32.pdf Here is the LH inlet. Would would the rh inlet go to 10 volts but it the LH? 2021-02-11-15-12-12.pdf Quote Link to comment Share on other sites More sharing options...
Adamw Posted February 12, 2021 Report Share Posted February 12, 2021 I think potentially this noise could be your issue, anything above about 1.8V on a DI is going to be considerd a tooth. Its hard to guess where that noise is coming from though, there are way more spikes there than spark events so it doesnt look like it is related to ignition (there would only be 6 sparks per 3 cam teeth). What RPM was that scope capture done at? Quote Link to comment Share on other sites More sharing options...
zwhitebread Posted February 12, 2021 Author Report Share Posted February 12, 2021 It was taken at idle. I checked it at 3k and it looked similar. The noise never went over 2.4 volts. Is there anything I can do to try to fix the noise? Quote Link to comment Share on other sites More sharing options...
Adamw Posted February 12, 2021 Report Share Posted February 12, 2021 I see about 5 spikes every 20ms, so that works out to 250Hz. Looking in your tune the only thing running at 250Hz is the 4 VVT outputs. So it looks like possibly noise from the vvt solenoids is being inducted into the sensor signal somewhere. If you still have access to the scope could you try again but with the VVT lockout set to say 5000RPM (so the solenoids are off) and see if that noise is then gone. Quote Link to comment Share on other sites More sharing options...
zwhitebread Posted February 12, 2021 Author Report Share Posted February 12, 2021 Here is the LH inlet sensor with the vvt locked out. This is at idle 2021-02-12-04-43-15.pdf Quote Link to comment Share on other sites More sharing options...
zwhitebread Posted February 12, 2021 Author Report Share Posted February 12, 2021 ok. here is the weird part, with the vvt not locked out the signal looks was better than yesterday. It doesnt have the spikes like it did yesterday. Quote Link to comment Share on other sites More sharing options...
Adamw Posted February 12, 2021 Report Share Posted February 12, 2021 In the scope above with the VVT off your spikes are much smaller, less than 1V, and the spikes that are there appear to be spark related now. 5 hours ago, zwhitebread said: ok. here is the weird part, with the vvt not locked out the signal looks was better than yesterday. It doesnt have the spikes like it did yesterday. Maybe try moving the scope wires around, possibly originally they were running close to the vvt solenoids and picking up the noise? Im almost leaning towards it being a ground issue but hard to tell still. How/where is the ecu grounded? Are you using a modified factory loom or is it a custom loom? Quote Link to comment Share on other sites More sharing options...
zwhitebread Posted February 12, 2021 Author Report Share Posted February 12, 2021 The wiring loom is custom from the ecu to the engine plug, where it retains the factor engine plug. All the engine wiring run through this plug except for the cam sesnors, they all run directly from the ecu to their respective sensors using shielded cabling and no plugs/splices The engine loom has been modified to only use the wiring that is needed. All the Ecu grounds are running through this plug directly to the engine block. The engine block had a 000 wire running from it to the battery. Quote Link to comment Share on other sites More sharing options...
zwhitebread Posted February 13, 2021 Author Report Share Posted February 13, 2021 After Playing around for a while i would say that the VVT solenoids definitely add noise, but they done seem to be causing the large spikes. 2021-2-12-16-42-15 VVT completely off.PDF Quote Link to comment Share on other sites More sharing options...
Adamw Posted February 13, 2021 Report Share Posted February 13, 2021 Yeah I agree, its looking like spark events in that latest scope. Does it have resistor spark plugs? Are the coils grounded to the heads? Stock coils (ie not cheap clones)? Would it be possibly to add a supressor to the power supply to the coils (one on each bank) or do they have supressors factory? Quote Link to comment Share on other sites More sharing options...
zwhitebread Posted February 13, 2021 Author Report Share Posted February 13, 2021 The coils are all oem. The spark plugs have resistors. The coils are grounded to the rear of the block (but at a different location than the ecu grounds). It does not have factory suppressors. Do you think I should get some suppressors as my next step? Quote Link to comment Share on other sites More sharing options...
zwhitebread Posted February 13, 2021 Author Report Share Posted February 13, 2021 Also If that is what I should try what style of suppressor do you recommend? Quote Link to comment Share on other sites More sharing options...
Adamw Posted February 14, 2021 Report Share Posted February 14, 2021 I think it is worth a shot, im still not confident those spikes are your issue but they have potential to be and dont see much else wrong so we might as well try to eliminate them. Supressors are usually a 0.5-3uF, you may find one as a small square black box near the coils on many modern cars, sometimes on the back of an alternator, or you can use an old school "condensor" like you have on a points car. "UBZ111" is a common aftermarket one like below. Some of the OEM ones are a bit nicer design with two pin connectors etc. Quote Link to comment Share on other sites More sharing options...
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