I recently put a vaccum gauge in and was using an electical gauge (glow shift). When I turned the car on it would work fine for about 2 or 3 minutes, then it would jump back and forth in a 4-5 in/hg incriment. At idle it will do it and when I'm crusing. At full throttle or when load is put on the car, it doesnt to it and works fine. So I thought it was becuase it was a cheap gauge, so I took it out and got an autometer mechanical gauge, however it acts the same exact way. I just serched this and found that it is the VSV pulsing. I just disconnected the sensor and it seemed to have fixed the problem, however I just let it idle, I havn't driven around yet. Could dissconnecting that sensor hurt me in anyway or be bad for my economy?

Thanks.

 

Yes the purge vsv would cause that to happen depending on were you tapped into for the vac gauge. That is a vacuum switching valve for the evap system and yes you need it. That is an emmisions control device and your computer will know if its not their. As for a vaccum problem------you dont have one. That is the normal operation for the VSV to kick in after the engine warms up. As for why you dont have weird readings from your gauge under load or WOT is simple. Your engine does not produce much vaccum when your gettin on the gas.

 

Thanks for the reply. I just disconnected the battary to clear the CEL after I reconnected the VSV. All of the sudden, my sunroof and pass. window control on the driverside doesn't work. I'm hoping it is a fuse. I'm going to check it after class today. Just in case it isn't a fuse, why would that have happened? I just bought my tC 3 weeks ago. Thanks.

 

The windows and sunroof have a anti jam sensor that loses memory when you disconect the battery. All you have to do is teach the computer by cycling the window up and down from the drivers window switch, then the passenger window switch, and finally the sunroof switch. This is confirmed when the light in the window switch is lit solid and not flashing.

 

Toyota doesn't mess around when it comes to technology in their vehicles. Your car is a lot smarter than you think.