Volvo 5 cyl cam position feedback and VVT issues

EMU BLACK / CLASSIC
1

I have my B5244S running on EMU black. It’s set up with a crank mounted 60-2 trigger and hall sensor and the original cam sensor on the original Volvo 5 lobe trigger wheel. I have issues with intermittent no-start, although it claims it’s synced. Sometimes it starts right away but most of the times I have to crank-stop-retry a few times before it fires up. Suspecting it doesn’t always find the right cam phaze, depending on where it rests before I hit start.

I also cannot get any VVT response. It’s setup OK, I’ve checked the output and even changed the valve but cam1 valve DC never leaves 2%. Cam1 angle follows whatever i put in Cam offset.

It seems the EMU isn’t really reading cam angle.

Also - Ignition angle lock does not change TDC reading with test light. Whether it is on or off the timing doesn’t seem to change.

The engine starts and runs “ok” but feels gutless, especially at low rpm

I am running out of ideas and GPT has no more suggestions.

Volvo B5244S

  1. 60-2 crank wheel
  2. 5-lobe Volvo intake cam wheel
  3. N+1 decoder
  4. Engine synchronizes and runs
  5. CAM1 angle follows CAM offset
  6. CAM1 target changes
  7. CAM1 valve DC remains at 2%
  8. PID terms remain zero
  9. Solenoid verified functional

“Is the Volvo 5-lobe cam trigger supported for closed-loop VVT angle control with the N+1 decoder, or only for synchronization?”

2

Here are my current settings.
I have confirmed VVT output, physically seen the valve move under output test.

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3

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4

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5

Cam trigger wheel:

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6

Crank trigger wheel:

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7

Screenshot while engine is running. Cam angle DC 2% never changes, regardless of rpm or cell value. (PS. I set the first cells to 25 just to try and provoke reaction)

Also note cam sync trigger tooth = 0
Sometimes it’s 65, sometimes it’s 113 (or 112).
Makes no sense to me..

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8

The only way it starts is with primary trigger “enable cam sync tooth window” - Disable
and secondary trigger “Enable sync without camsync” - Sync as soon as cam is decoded.

9

Finally decided to try a 1 cam tooth strategy. Had a spare wheel so I cut all but the longest tooth.
Rechecked timing, played with trigger settings and vvt map.

Now it starts on every attempt and I have active functioning VVT. Gotta keep tuning the VVT map but this is way more promising.

Why it wouldn’t behave with 5 lobes and N+1 I have no idea.. in theory it should be fine..