discombob

Hey all,

I've been having an AVCR problem. It seems to have stopped working a couple weeks ago (running off of Tial gate w/blue spring @ ~14 psi) and isn't coming back, even after I performed the following troubleshooting steps:

-took apart and cleaned solenoid... tested directly off of the battery (12v) and heard the click (also get a single click at ignition power)
-checked vacuum line feeding solenoid for suction at idle and plenty abounds
-took apart my Tial wastegate, cleaned and inspected it... bench "tested" it by putting it in a shop vice, pushing down on valve and checking for vacuum through forward ports. It seemed all right and could not visually see any holes in the diaphram. I spray-cleaned and graphite-lubed the valve shaft and put it back together with a double-check on my vacuum connections.
-pressurized system on intake side of turbo with an air compressor and a homemade schrader-valve-in-PVC-cap-to-rubber-elbow-with-clamp kinda thing and could not hear any leaks in piping, BOV or intake
-have an older HKS bov with adjustment screw... have no idea how to test if the BOV is leaking aside from what I did above. I don't know much about BOVs or how to maintain them.

If I disconnect the solenoid harness, the AVCR doesn't tell me there's a problem, which was a bummer. RPM and throttle position tap-ins on ECU harness show voltages on AVCR.

I'm trying to get the AVCR to take me from 14 psi off the wastegate spring up to 18 psi again, where I was before it suddenly just stopped working. I have reset the unit and re-configured it with proper vehicle-type settings and target boost at 1.30 kg/cm2 (18.something psi). No matter how high I turn up the duty cycle, I never hit higher than about .95 to 1.01 in 4th at WOT and the car bogs from running rich up top since it is running a socketed Neptune.

I was hoping I could fix this without throwing money at the issue and start replacing the solenoid, BOV, etc and just praying it will work. Does anyone have any ideas?

Much appreciated!

Turbo-charged

take the vac. line off the side of the gate. if boost doesn't go up then, you have to have a leak of some sort.

discombob

OK, I took off the vacuum line, as suggested (thanks) and the boost went up pretty aggressively to 1.36 kg/cm2 about 1.5k shy of redline, so I easily hit and blew through my target this way. I could probably play with duty cycle now and get it to match what I need.

I suppose this indicates that something is different with my vacuum configuration/pressure since the problem appeared? The idle quality went south a little once it was disconnected, so I guess I need to play around with my vacuum connections so it isn't suckin' so hard... what should I start with?

discombob

UPDATE: I checked all the vacuum lines and nothing is leaking... I guess now I should try a different solenoid on the AVC-R, even though it clicks when it gets power? I wish I understood this custom turbo stuff a little better before I jumped in. It's hard to find assistance here/a local shop that knows what to do and how to test.

discombob

bump... help?

smoovy

I am currently using the AVCR and it's fairly complicated to troubleshoot it but it sounds as though your solenoid is fine. I wouldn't change it unless that was a last option. vacuum leaks would come to mind but you've checked everything including the sensor vacuum line? I'm sure that feeds info to the brain to let the solenoid know what to do. another thing is to hook everything back up the way it was and try playing with the solenoid duty cycle. also check your sensors output on the AVCR. I don't have the manual in front of me to let you know what it's supposed to read, but just a couple other things you can look at.

NJIN BUILDR

Go through your set up screens again before you get carried away.I accidentally turned off boost while trying to change some settings in the staging lane.Drove me nuts until I caught it.

discombob

Thanks for those replies. I already performed a reset and reconfigured the AVC-R from scratch after using the forum's search feature brought up an issue where several users reported scrambled settings/memory when switching between A and B presets.

Everything looks good afterward. Sensor voltages are reporting correctly. Throttle sensor orientation looks good. Duty cycle adjustment does next to nothing... gets me to about 1.05... trying to hit and hold 1.30.

All vacuum lines are running off the (stock) intake manifold ports.

Tony the Tiger

Try to change the vacuum line configuration...

Have the lower port of the wastegate get its signal from the intake manifold, and have the top port of the wastegate get the signal directly from your compressor housing.

This will introduce a slight pressure differential between the top and bottom port, and should allow you to boost slightly more. It also takes the vacuum out of the equation and prevent and possibility of the solenoid being stuck in one direction due to vacuum.

I would also check for a leak/pin hole on the hose that leads to your BOV. A weak signal to the BOV will cause it to prematurely open and leak boost.

Lk4z-slc

I ventured out from the VW forum for this one . I have the same exact problem with the AVCR in my Vr6-t. All was great for a few months when first installed. Out of nowhere, my boost pressure drops down from 22 psi to 13, the next day I'm running off the damn wastegate spring (small blue 8.70psi) and have nothing. Its not a problem in the vac lines. I thought I killed the MAP sensor with moisture from alchohol injection, since I forgot to put in the little air filter they give ya, nope. I bough a new pressure sensor, no good. Ok, next is the solenoid.. I pulled it apart, looks good, tested it Via 12v and hear it latch. (you can actually feel resistance change while blowing through it and touching it to power.) seems to work fine. The AVCR head unit does nothing at any boost level or duty. All sensors read perfectly. I swapped to a MBC and the car was fine, i was able to adjust boost perfectly. Wastegate, Vac lines, spring etc. are all brand new and working 100%. My conclusion, is that the damn AVCR head unit is screwed up and not actuating the solenoid. I already bit the bullet and bought a new solenoid which will be here shortly. Just for kicks I want to try it and see if there's a possibility the solenoid is bad. I'll contact Apexi usa tomorrow and see what they have to say. The thing is brand new (2 months old) I shouldn't have to be replacing sht already.

The only way to really test the head unit manually is putting a meter or test light onto the sol. harness end and seeing it light up when while in boost. (obviously requiring a passenger) Other than that, the solenoid duty cycle can be monitored on the head unit, but as I found out, its registers no different just like it was working fine.

This isnt a common problem with the AVCR, I just wanted to share my experience and where I got with it to save you some troubleshooting time. I'll update shortly on where I get with it.

Sorry for the threadjack bro!