Ill take water bypass parts for $1000 alex.

IN the pic below these are what parts and what do they do.



from left to right

a temp sensor but for what?
the idiot light sender?
main takeoff for heater core (this i know)
yet another temp sensor again for what?
vacume temp sensor for something? (perhaps cold start something??)
nipple take off for something..

notice there is yet another casting hole (back left) i can drill out and tap for an aftermaket sender. but my question is to find out what all those other ones do and can i simply elimante one and replace it with the temp sender for my autometer gauge.

 

the one with the black connector looks like the cold start time switch, the grey one is probably for the ECU, and the other one is for the gauge on the dash

 

The part far right is the TVV that has a vacuum line that connects to the charcoal canister. The sensor far left is temp sensor and the one with the black is the cold start injector time switch. Not sure on the small one..

 

Thanks for the info. Im sticking to my theory that the little one is some sort of idiot light sender.

 

temp sender

 

Anyone have a Part # for the black one second from right?

 

The Switch, Start Injector Time is 462-20040. $130 at ToyotaPartsZone.com

 

I need to revive this thread guys. I want to get all new sensors.. But they are pricey.. does anyone know if this bypass is explained with all its sensors in the fsm? I'm gonna dig into it and perhaps I can save some time

 

It isn't (at least not in any detail). It's also not very standard; snap-on talks of a casting hole to drill out; that's for trucks with automatic transmissions, which need their own add'l temp sensor.

Why are you thinking of replacing "all" the sensors?

 

well I am getting my engine rebuilt, I'm putting in a bunch of new parts. I'd hate to put everything back together and have an issue only to spend 5 years torubleshooting to find out it's a sensor... these sensors have 216k miles...

I'll attempt to test them first.. I ordered an "Engine Coolant Temperature" sensor.. that was a few bucks. But there is an "Engine Temp sensor" that is over 100 bucks.. and then there are those other sensors I dont even know... I just want to cover all my basis to give this rebuild the best chance at success

 

DO check them first. But if you insist, this may help a little:
http://www.toyotapartsoverstock.com/...rimLevel=18292

 

excellent! Thanks.. why couldn't I find that?

 

Because it's under "Entertainment." Go figure.

Looking through these drawings and lists will make you much more understanding of how difficult it is for a dealer or parts store "counterman."

 

https://www.yotatech.com/forums/f116...l#post51976946

Parts diagrams in the link too...

The wide coolant flow tube in middle is for the heating system either to/from heater core depending upon your setup (there's a couple different variations due to the rear heater in 4 runner, nto sure if they use the same ports or not). The skinny one is the number 3 coolant bypass hose. For california vehicles it runs one of two hoses to/from the EGR. In the rest it connects to another coolant port about a half inch away on the rear of the engine. Otherwise, everything is covered in link and/or above.

 

Thanks guys..
Yesterday I noticd that the lines going to the rear heater are completely full of... junk... Another item I need to rip out.

I like to understand the pieces I am working with, and you guys are making my life much much easier