RomRaider

Hey guys,

looking through the logs from a recent autocross, i found my AVCS seems to be really slow.

Here's a 2nd gear pull accelerating out of a corner:


And here's my AVCS table(s, Cruise and Non-Cruise are identical):


The framed section of the log shows left and right avcs angles, which should be 20°+ in that RPM/Load range, but take almost 2 seconds to get even close.

Is there something in the ECU that could do this on purpose?
Or do i have hardware/oiling issues?

Car is 08 WRX + VF52 (stock otherwise)
Oil is 1 month old.

I have the same problem. However I am sure when the car with new it was in sync. but I checked some of the logs for other cars and I rarely found a matching AVCS. So i lived with it. even after engine rebuild its not matching.

I thought its the sensor so I switched left and right, still the same side that is lagging. so I ignored it and lived with it again.

Verify oil pressure at 1000-3000RPM idle, coolant temperature 90C+. It looks that VVTs sit at lockers.
If there is no problem with oil pressure change OCVs.

Thanks Sasha!

I've been investigating some more, and i think this very case i reported here is more related to AVCS not having warmed up completely before.
In the log, this is the first instance of VVT values actually moving, so it might be related to me turning off the engine while in grid. (?)
Coolant had been warmed up for minutes already, but i guess AVCS (oil?) was not.

Anyways, looking through other parts of this and other logs, i can see my AVCS values usually moving at a maximum rate of about 20°/sec.
Does that sound normal?

Analyze VVTs together with OCV duty.
Cold oil may limit VVT change speed.
That is why FB engines have coolant related correction for VVT target.

OK, i haven't been following up on this for a long time, but i've come across it again as i was trying to tune spool.

It appears that, if it happens, OCV duty is not going up as high as i would expect it from the VVT targets that are set in the map.
Does that mean the ECU isn't even trying due to some compensation going on?

Here's a "bad" example:


For comparison, a few minutes after that pull i did another one, with VVT values looking normal to me:


Oil pressure has been >5 bar at all times, oil temp 95°C.
Coolant temp 86°C for the first (not ok) pull, 83°C for the second (ok) one.

update on this as well I have changed the Solenoid and it started working.

So it was a lazy solenoid?

One more thing to check is the oil screen in the AVCS oil line. Where the oil lines connect to the head, there are screens inside the banjo bolt that can get clogged and cause this problem.