I just got a 1991 4runner with the 3vze engine. I replaced the head gaskets and got it all put back together. i am having a throttle problem, when i am at highway speeds (55-65) and about 10-20% throttle the engine surges from about to 1200rpm to 2000rpm. Could this be a dead spot in my TPS? Also i have black smoke coming out of the exhaust pretty noticeable at idle. NO check engine light, other than the 2 problems listed above it runs great! Any and all suggestions are greatly appreciated. You all ROCK on this site!

Jared

 

I can't say for your engine for sure... but my 22RE had throttle issues like that and it was a bad o-ring at the throttle adjust screw on the throttle body. Look for a vaccum leak anywhere, especially around the throttle body.

My smoke almost completely went away when I put a new disptick in, sealing the crank case. Make sure you don't have any crank case ventilation issues--oil cap, PCV...

I am no expert, and never worked on a 3vze, so please keep that in mind! Good luck!

 

where is the pcv valve on the 3.0 passenger side?

 

PCV valve is under the intake manifold, You should have a hose going from you intake plenum to it on the back side. i can take a picture if that would help.

 

My thoughts are that you have a hose disconnected somewhere and making the computer see a lean condition, thus compensating with more fuel (hence black smoke) The TPS is easily testable http://www.4crawler.com/4x4/CheapTricks/TPS/index.shtml Also check your bigger rubber intake boot that connects silencer to the throttle body. They are usually cracked near the TB allowing extra air to enter after VAFM.