club.liberty.asn.au

Hi members. I recently did an ej207 sti ver10 shortblock swap on my jdm legacy gt. Was pretty much plug and play. Reused the stock dual avcs U20 heads. Just that exhaust vvts are not working since the new Shortblock swap. Intake vvts are reading well.

Exhaust vvts are stuck at zero, tested the solenoids n cleaned them still no fix. Has anyone dealt with similar issue of exhaust vvts stuck at zero degree after sti shortblock swap?

Btssm log pic attached for reference.
Any help and advise would be appreciated.
Thanks

You can get to the avcs failure mode by first testing the OCV’s in place.
Start with a cold engine, *all* accessories off, key on, engine off, *reset ecu*, key off, key on engine off, press rear defrost switch (option to log on rear defrost must be enabled in btssm or romraider logger software, engine on and allow the engine to idle with nil haptic control input until fully warmed up.

Open the log in eg MLVHD and plot VVT angles vs eg rpm & coolant temp. Does avcs attempt recalibration at 65’C?.
After the engine is fully warmed up go for a 20minute drive and include very steady freeway cruise eg using cruise control.
Does VVT activate, does VVT sync?

Let’s say there’s no VVT sync, no VVT angle.
You can put the car on hoist or stands, remove the engine undercover and log the idling engine whilst pulling the ocv harness plugs and individually powering each ocv in turn with a 5volt power bank positive and negative or same from a 9 volt battery.

In the datalog, does the VVT angle go to max on external power?
This test isolates the avcs fault to either the OCV or the OCV harness or the ecu.

Iirc I did look at your logs, after ecu reset and avcs recalibration your VVT angles were stuck at 7 and 5 degrees with no variation from that during driving.
Did you get any further into your diagnosis?
I’d recommend remote powering the ocvs next.

bigBADbenny wrote:Iirc I did look at your logs, after ecu reset and avcs recalibration your VVT angles were stuck at 7 and 5 degrees with no variation from that during driving.
Did you get any further into your diagnosis?
I’d recommend remote powering the ocvs next.

Update: i got this issues fixed. It was the timing belt not aligned properly. Was 1 tooth off which caused the exhaust vvts to stay shut. Corrected the timing and aligned it well at correct marking, now the vvts read properly.

Thanks very much for updating with your positive outcome!
Did you find out any more specifics? Eg which bank was affected, was it specifically one tooth out, was it advanced or retarded?