Targetengineering Posted September 2, 2020 Report Share Posted September 2, 2020 Hi Folks The Mk3 Supra engine uses a Cam Position Sensor Toyota called a CPS. It’s gear driven like a distributor from a camshaft, so its internal rotor spins at half crankshaft RPM. internally it has a profiled rotor with two 180deg opposed magnetic sensors that Toyota name G1 & G2 respectively. Also there is a 24 tooth reluctor wheel with its own magnetic sensor situated behind the profiled rotor. On the 7m engine the CPS triggers three ignition coil igniters and I think it provides an RPM signal to the ECU. Im trying to use the CPS unit in a 2JZGE engine in the Mk4 Supra. In my application I’m only using the G1 pickup to provide the Cam signal (Trigger 2) for the LinkG4+ ECU. Trigger 1 is from a 12 tooth reluctor fitted on the crankshaft. My question is: Has anyone used the CPS successfully with the Link G4+ ? Also does anybody have the trigger waveform, as I’ve been having trouble getting it to work. Thanks Quote Link to comment Share on other sites More sharing options...
Simon Posted September 2, 2020 Report Share Posted September 2, 2020 These settings should have it very close. Be sure to do the trigger calibration to set up the base timing. Quote Link to comment Share on other sites More sharing options...
Adamw Posted September 2, 2020 Report Share Posted September 2, 2020 Does this sensor share a single ground wire for trig 1 & 2? Because your scope pic above shows trig 2 is wired back to front - that may mean trig 1 is back to front also if they share the same ground wire like most Toyota CAS's. But otherwise if you fix that the signal looks usable and the ecu should have no trouble running it. Why do you believe there is a trigger issue - do you not have RPM when cranking? Quote Link to comment Share on other sites More sharing options...
Targetengineering Posted September 3, 2020 Author Report Share Posted September 3, 2020 Trigger issue ! Quote Link to comment Share on other sites More sharing options...
Targetengineering Posted September 3, 2020 Author Report Share Posted September 3, 2020 13 hours ago, Adamw said: Does this sensor share a single ground wire for trig 1 & 2? Because your scope pic above shows trig 2 is wired back to front - that may mean trig 1 is back to front also if they share the same ground wire like most Toyota CAS's. But otherwise if you fix that the signal looks usable and the ecu should have no trouble running it. Why do you believe there is a trigger issue - do you not have RPM when cranking? The owner has done much of the wiring himself. As far as I understand him, he has a two core screened cable to the cam sensor and a two core unscreened from the crank sensor. On one of the scope plots that I posted to you, it looks like the cam (trigger 2) trace has much of the crank signal merged together from the trigger 1 trace. This makes me wonder if there is a bad ground connection in the ECU multiplug connector. The RPM signal is intermittent whilst cranking !! im interested in your comment that the trigger 2 signal is inverted. Should we therefore reverse the cam sensor polarity? Quote Link to comment Share on other sites More sharing options...
Adamw Posted September 3, 2020 Report Share Posted September 3, 2020 8 hours ago, Targetengineering said: On one of the scope plots that I posted to you, it looks like the cam (trigger 2) trace has much of the crank signal merged together from the trigger 1 trace. I think there is more going on that that - it looks like there is a roughly 10Hz 5V square wave coming through on top of both of the trig 1 and trig 2 signals. Im not sure if that is coming from something else in the car or something the ECU is controlling - but it likely means the ECU doesnt have a proper power ground to the engine - so all ground current is passing through the trigger circuit. What ecu is it? Quote Link to comment Share on other sites More sharing options...
Targetengineering Posted September 4, 2020 Author Report Share Posted September 4, 2020 G4+ Quote Link to comment Share on other sites More sharing options...
Adamw Posted September 4, 2020 Report Share Posted September 4, 2020 1 hour ago, Targetengineering said: G4+ I kind of figured that since you were posting screenshots from the G4+ software in the G4+ forum. But what I meant was, is it an Atom, Monsoon, Storm, Xtreme, Fury, Kurofune, Thunder or plug-in? And if its a plug-in - which specific model plug-in? Quote Link to comment Share on other sites More sharing options...
Targetengineering Posted September 4, 2020 Author Report Share Posted September 4, 2020 Hi Adamw, sorry I wasn’t being flippant, but I didn’t know a more specific answer at the time. Apparently it’s a G4x plug in. It says 211-3000 on the box if that helps ? Quote Link to comment Share on other sites More sharing options...
Adamw Posted September 4, 2020 Report Share Posted September 4, 2020 Ok, so that part number is a Mk4 supra plug-in. Is it a 2J in a mk3 chassis? Has it got a 2J loom fitted? Your triggerscope suggests the main ground may be missing - The square wave we are seeing I think is the stepper motor current flowing through the trigger ground. Pins B69, B79 & B80 are the main power ground, can you check these have continuity/low resistance to the engine block. Also check the battery negative to engine block and chassis has low resistance. Quote Link to comment Share on other sites More sharing options...
Targetengineering Posted September 5, 2020 Author Report Share Posted September 5, 2020 Hi Adamw The car is a Mk4 Supra with the factory harness. We should get a chance to do some checks today hopefully. I’ll report back with findings when I have something. Attached photo is the actual engine from this car. Quote Link to comment Share on other sites More sharing options...
Targetengineering Posted September 6, 2020 Author Report Share Posted September 6, 2020 Ok, so today I got a couple of hours to try and verify some of the trigger signals. To test them I did a continuity resistance check from the sensor end to the ECU 80pin harness connection (with ECU Removed). Results measured 0.3-0.4 Ohms typically. I then tried a storage scope connected at the ECU connector end to see the cam signal. With a modern scope I seemed to pickup lots of noise. So I tried an old CRT scope and measured the sensor waveform at about 1volt peak to peak. Having moved the ground for the crank sensor from a chassis ground to the signal ground we finally set the base timing and finally got the engine to start ! Quote Link to comment Share on other sites More sharing options...
Adamw Posted September 7, 2020 Report Share Posted September 7, 2020 Glad its working, but it still looks pretty fishy like there is a ground missing or something. On 9/5/2020 at 9:35 AM, Adamw said: Pins B69, B79 & B80 are the main power ground, can you check these have continuity/low resistance to the engine block. Also check the battery negative to engine block and chassis has low resistance. Did you do this? Quote Link to comment Share on other sites More sharing options...
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