VIS Valve?

[Lazzman]

Anyone know how to check to see if the VIS valve is working properly on a 4.0 sohc motor?

The VIS Valve is the thing that is mounted on the top of the upper intake and it lets additional air in the intake above 3000rpm's. It is controlled by a vacuum actuator.

I replaced the whole VIS motor assembly last september, but still do not know if it is opening at 3000rpm as it should?

Since my problem starts at 3000rpm and goes to 4000rpm, I thought I would give it a looksy.

Anyone know what part controls the actuation of this VIS Valve? I know it is a vacuum piece and I think it is mounted behind or to the side of the EGR Vacuum solenoid.

 

[aldive]

Post a pic of this valve, please.

 

[JDraper]

You need a SCAN tool to check it, and from what I've read about the system, you're better off letting a good quality shop check it out.

 

[Lazzman]

Al, it is on top of the upper intake manifold just behind the IAC valve.

Thanks for the info JD...

It would stand to reason that if my problem was in the 3000rpm range and the motor was counting on the VIS valve to open at 3000rpm and send double the air through the intake. This may be my problem.