I just bought a 91 4runner that has 235k on it but it's in excellent condition inside and out. But, the engine light came on and i was told it was the vacuum regulator valve. The mechanic tried to get $100 for the valve and $70 in labor, didn't happen. I'm wondering how i can check the valve to make sure it's bad. Also the 4runner runs great but it's a little sluggish especially uphill of course. Any ways to pep it up?? Already have a turbo muffler and bigger tailpipe and k&n.

 

A better description of the valve might help. If it is a Vacuum Switching Valve (VSV) there are two things to check, one is the resistance of the coil, usually something under 100 ohms. And then see if the vacuum switching part passes vacuum when energized and blocks flow when off.

 

Well that's what it's called, vacuum regulator valve. It's on the top front of the engine, it has two hoses going in (R&P) and 1 coming out (Q). And there is one bigger hose straight out the bottom.

 

Sounds like the EGR modulator valve. Check in the Factory Service Manual for testing procedures.