Subaru 36-2-2-2 VVT No Cam Signal
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Subaru 36-2-2-2 VVT No Cam Signal
MS3-Pro; 1.5.1 beta 6
I am going through the recommended pre-start checks and I can not get a cam signal. It appears that MS3 is cycling the fuel pump relay on and off during cranking. Since my engine sensors are powered by a relay that is triggered by the fuel pump relay, I think may be my issue (I can hear them clicking on and off during cranking).
Why does MS3 cycle the fuel pump relay during cranking? Do I have something configured wrong?
MSQ, MSL, and Composite logs attached.
I am going through the recommended pre-start checks and I can not get a cam signal. It appears that MS3 is cycling the fuel pump relay on and off during cranking. Since my engine sensors are powered by a relay that is triggered by the fuel pump relay, I think may be my issue (I can hear them clicking on and off during cranking).
Why does MS3 cycle the fuel pump relay during cranking? Do I have something configured wrong?
MSQ, MSL, and Composite logs attached.
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Re: Subaru 36-2-2-2 VVT No Cam Signal
Power/control the "sensors relay" from a source that is on whenever the MS3 is powered. The FP relay won't turn on until cranking (sync) is detected, and that requires having the CKP/CMP sensors already powered. I'm kind of surprised you are getting any FP action at all.
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Re: Subaru 36-2-2-2 VVT No Cam Signal
I removed the sensor relay all together by jumping pin 30 to pin 87 with no luck, same effect, FP cycles on and off, still no cam sync.
In the logs you can see the RPM drop to zero when the FP shuts off even though in the composite log the crank signal does not miss a beat.
In the logs you can see the RPM drop to zero when the FP shuts off even though in the composite log the crank signal does not miss a beat.
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Re: Subaru 36-2-2-2 VVT No Cam Signal
"even though in the composite log the crank signal does not miss a beat"
What??? There is continuous sync-loss in both the run (MSL) and composite (CSV) log. It's no wonder the FP is clicking on/off like that.
What??? There is continuous sync-loss in both the run (MSL) and composite (CSV) log. It's no wonder the FP is clicking on/off like that.
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Re: Subaru 36-2-2-2 VVT No Cam Signal
The sync loss is due to a lack of cam signal I believe. I get "Half Synced" indicators while cranking. When I switch to semi-sequential and wasted COP I get full sync. If I was not getting a good crank signal it would not work in that mode either.
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Re: Subaru 36-2-2-2 VVT No Cam Signal
Sync loss can't be ignored, regardless of what the cause. If it syncs and starts runs OK with wasted-COP, post that MSQ and MSL; let's work with it like that for a while. I suspect, though, that it doesn't start, even when you think you are seeing "sync" on the dash.
Alas, I probably can help much with that weird Subaru crank/cam pattern; I have never bothered to try to understand it.
Alas, I probably can help much with that weird Subaru crank/cam pattern; I have never bothered to try to understand it.
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Re: Subaru 36-2-2-2 VVT No Cam Signal
Just the sake of completeness, here is the tune, log, and composite log when cranking with semi-sequential and wasted cop. Again the crank signal is great, same as under full sequential. Note the fuel pump does not cycle on and off under semi-sequential mode.
I do not know if the lack of cam signal is causing the fuel pump to cycle on and off or if the fuel pump cycling on and off is preventing a cam signal from being established. Chicken and the egg type thing.
I do not know if the lack of cam signal is causing the fuel pump to cycle on and off or if the fuel pump cycling on and off is preventing a cam signal from being established. Chicken and the egg type thing.
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Re: Subaru 36-2-2-2 VVT No Cam Signal
Does the cam signal appear if you change spark mode to "log crank and cam"?
Matt Cramer -1966 Dodge Dart slant six running on MS3X
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Re: Subaru 36-2-2-2 VVT No Cam Signal
It doesn't look like the MAF sensor is responding. I don't know how that fits into all this, but it can't help any. Will the engine start and run, in any mode?
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Re: Subaru 36-2-2-2 VVT No Cam Signal
For people wondering, I did a video on trigger logging that has a section on Crank and Cam logging
https://youtu.be/0-8UEyuCZ2I?t=133
Hope this helps
Andy
https://youtu.be/0-8UEyuCZ2I?t=133
Hope this helps
Andy
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Re: Subaru 36-2-2-2 VVT No Cam Signal
No it does not appear to. But the fuel pump was not on during Log Crank & Cam so neither was the cam sensor! I''ll try again with the cam sensor powered up off a different source.Matt Cramer wrote:Does the cam signal appear if you change spark mode to "log crank and cam"?
Last edited by jsiedlicki on Mon Sep 18, 2017 10:00 am, edited 1 time in total.
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Re: Subaru 36-2-2-2 VVT No Cam Signal
The MAF is unplugged. I am just trying to get a solid sync before trying to start the engine.billr wrote:It doesn't look like the MAF sensor is responding. I don't know how that fits into all this, but it can't help any. Will the engine start and run, in any mode?
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Re: Subaru 36-2-2-2 VVT No Cam Signal
@Matt
Ok retried with the sensors powered up independently of the fuel pump, still no cam signal?
Ok retried with the sensors powered up independently of the fuel pump, still no cam signal?
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Re: Subaru 36-2-2-2 VVT No Cam Signal
Ok, went back to basics. I pulled out the hall effect cam sensor and tested it. It needs a pull-up. I'll report back when I get some 1k resisters fitted into the harness for the 4 cams.
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Re: Subaru 36-2-2-2 VVT No Cam Signal
Great, please keep us posted on what you find.
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Re: Subaru 36-2-2-2 VVT No Cam Signal
That was the issue. I now have a cam signal.
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Re: Subaru 36-2-2-2 VVT No Cam Signal
How did you do the pull up circuit?jsiedlicki wrote:That was the issue. I now have a cam signal.
Which of the cam sensors are you using the one on the battery side or the one on the turbo side?(turbo side in ej engines)
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Re: Subaru 36-2-2-2 VVT No Cam Signal
This is not an EJ engine. Its a Subaru EZ36R flat 6. I am using all 4 cam sensors (2 intake and 2 exhaust) but the primary cam signal is on bank one intake. I simply put the 1K pullup resistor into the harness close to the sensor, joining the 12V power to the sensor line.
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Re: Subaru 36-2-2-2 VVT No Cam Signal
Thanks i will give that a try