I went to a local dealership where they had to reset my idle, I asked them about my VIAS and why i wouldnt feel a big jump when it turnedon. They hooked up the consult II and took it for a test drive. The consult II verified that the VIAS was not turning on when hitting wot. Now they tested and found that the vias was actuating and still was not clicking on. HMMMMMMMM what do you guys think???? What could be the problem??????

 

The VIAS doesn't come on at WOT, per-se .. only after a certain RPM ... It was actuating, but not clicking on

Maybe you have what other members have ... broken VIAS.

 

HAHAHA ok guy here me out again. The actual hosing that goes into the VIAS right, we blew air through it to hear it actuate follow me now. I know it sounds totally rediculous but thats wat we did. After that we tested it with the consolt II and we saw that the VIAS still did not turn on. But when we turn it on Manually through the consult we hear and feel a world of difference. Now i know its not busted but why would it not turn on???

 

Where's BlackBIRD.

 

So ECU is sending power to turn on at 5000 rpms?

 

i do not understand how the consult could manually turn the vias on. i have limited experience with the consult 2 but i dont remember this particular parameter. the only thing i could see would be the ecu sending the signal to switch but perhaps the rod is spinning freely in the cup and therefore not actuating. easiest way to find out would be to take it apart.

 

it could still turn, but the rod won't be turning because of a mechanical failure.

 

exactly...the actuator is turning the rod but where the rod attaches to the metal cup is eroded and so the plastic valve doesn't turn at all or only partially. you have to remove the VIAS assembly and fix this area with JB Weld. search the forum or web for instructions.

 

ummm ok look the VIAS ITESELf is goooddddddd but for some other reason it does not work



until we turned it on electronically through the consult it did not work..... Are we clear or is there still some confusion??

 

did you actually unbolt the VIAS?

 

how much of a difference does a broken VIAS make? i never drove in a 5th gen before mine to tell if i'm as fast as i should be. Car definitely pulls at high rpm but not sure about low end...hard to compare to my 4th gen since i'm used to FI before this...

 

Yes, sounds like the signal from the ecu isn't getting to the actuator. Make sure that around 5000 rpm there is a signal going to the actuator (maybe check voltage of wire going to the solenoid?)

 

it really depends on how it breaks. if it breaks in the open position then your low end suffers but top end is better. if broken in the closed position which seems to occur the most, the low end is unaffected but the mid and upper rpms are underpowered. a local member did some dyno testing of his broken vias in the closed position then compared to removing the rod and he gained around 18hp to the wheels but lost torque. with the cup repaired and vias functioning, he got close to the 18hp back (compared to broken one) as well as the torque that had been lost when it was removed.

 

^^ yeah...the car should keep pulling right through redline...if it starts losing steam at higher rpms, then your vias isn't opening up...there was a nice dyno comparing the power curved w/ and w/o the vias.

http://forums.maxima.org/showthread.php?threadid=116808

 

Unless consult technology has changed, there is no way to determine whether the VIAS is working properly using Consult.

The service manual's only test is to see if the actuator rod flips when you hit 5k rpms. You can check this yourself by moving the throttle under the hood until the rod flips or you hit redline.

If the rod isn't flipping there is some type of vacuum problem.

If the rod flips, your vias may STILL not work. It is possible for the actuator rod to flip but nothing happens inside the intake to move the valves to change the airflow. That's the problem I had.

I had one of the first problems with this and went through hell to prove to the dealer that my vias was broken despite the rod flipping. Ultimately I dyno'd and there is a SUBSTANTIAL difference above 5000rpms. Don't quote me but I think HP and tq losses were as much as 25whp at redline.

Despite the significance of the loss, it is fairly hard to diagnose because of the small # of rpms at which the problem occurs. I could only prove it on the dyno and by running an identical 5spd.

One thing that you can try is to disconnect the vias by unplugging the plug directly below the unit. That will disable the vias. You can then drive it and see if you can feel any difference . . .

Otherwise, you will need to follow the instructions on using the JB weld or convince a dealer to give you a new variable intake (rarely happens).

edit: see the post above - it has a link to the dynos and it was 35 hp at redline.

good luck