buckz6319

Well "Christine" throws another curve ball (95 4runner 3.0)
I have been smelling gas around and under the engine for a while and also have a C.E.L. on code#71...and have checked all parts per the FSM that pertain to that code ,and all check out within specs

well to make a long story short I have located the source of the gas smell....the Tvv on the intake has a broken port(Blue in color) and the vacuum line from the Tvv goes to the purge side of the charcoal canister...so I would like to know
1) what does the Tvv stand for
2) I can't find a used Tvv but can find a BVSV...are they the same part with different names...if so can I use the BVSV?
3) will this Tvv not working properly cause my C.E.L. to come on?...my thinking is that it can?
thanks for any help
Dwayne

yoterr

well the BVSV is a temperature controlled vacuum switch, so once the truck reaches a certain temp it changes the vac routing, not the same as TVV i dunno what it stands for tho... but where did you find a BVSV? mines broke and yeah short of a junkyard i cant find one, and short of a junkyard means i have to drive 2 hours to get to one that has a toy lmao

buckz6319

yoterr...thanks for the reply....here is a link to a BVSV http://cgi.ebay.com/Toyota-Truck-4Ru...item35a410d30d this helps

RMA

looks like they are the same thing, but maybe not . I will look to see if I have one , I know I sold 2 of them ( VSV) to the same person, he broke the 1st one I sent him while instaling it.

yoterr

is the TVV installed in anything or is it just on the pass side fender well with like 5 vac hoses attached? i got one and its sitting in my garage.....

RMA

no its on the back of the 3.0 on top in the center with some other sensors.

buckz6319

RMA thanks for the reply.....I'm going to the auto parts store this morning to see if I can order the switch.....and if they can't order it I'll be looking for a used one

buckz6319

yoterr....was the BVSV ebay link I posted the correct part that you looking for?.....if not they have more used vsv listed in the same category....

BoostinChick

That's the VSV.

TVV is in the rear behind/under the intake plenum next to the coolant temp sensor. It connects to the charcoal canister and a port on the throttle body. If you check under the hood at the vacuum diagram it depicts it there.

TVV = thermal vacuum valve
BVSV = bimetallic vacuum switching valve

Same thing different name. The link posted by buckz6319 is the correct part. I broke mine off and it caused no CEL on my 3VZE. Code 71 usually refers to something EGR related.

EGR VALVE MALFUNCTION--EXHAUST GAS TEMPEATURE BELOW SPEC. FOR EGR CONTROL
--EGR SYSTEM

--EGR GAS TEMPERATURE SENSOR/CIRCUIT

buckz6319

just general information
Depending on what system you have there could be more to the system Quote from manual:
The EGR system reduces oxides of nitrogen emissions by lowering combustion temperatures. Combustion temperatures are lowered by recycling metered amoumt of exhaust gases back into the intake system.
The EGR system contains a vacuum operated EGR valve and EGR vacuum modulator. Vacuum modulator regulates exhaust backpressure and balances atmospheric pressure and vacuum to allow EGR operation at heavy throttle. A check valve,EGR cooler, EGR vacuum switching valve and EGR gas temperature sensor may also be used depending on vehicle application.
The EGR cooler used on some models, assists in reducing exaust gas temperature before entering the combustion chamber. On some models, EGR operation is controlled by a EGR Thermal vacuum valve TVV. The EGR TVV, mounted in the engine coolant passage, opens at a specified temperature, allowing the EGR operation.
On some models, EGR operation is controlled by a EGR Vacuum switching valve VSV. The engine control module ECM controls EGR,VSV for EGR operation. This system is referred to as EGR cut control system. The ECM uses various input signals such as engine coolant temperature,engine rpm, throttle position, brakelight signal, airflow meter and vehicle speed for controlling the EGR VSV. End Quote