norcalyota

so i ended up selling my 88' to and found this 92' that i purchased. turns out the guy had no clue about the truck. it has 60,000 original miles on it, you can tell it has never been off road or driven much. so here she is. this is my first time trying to upload pictures so hopefully it works out.







so i got some questions. the temperature gauge doesn't work, it will start out showing cold when i start it in the morning and after it should be warmed up it will go up just past the cold side, no where near the middle. then randomly it will go down slowly, or up a bit. i really want to fix this. i figured it wasnt the gauge itself being bad cause it does actually move. so i was thinking it is either the thermostat, or temperature sending unit. so i was looking in my haynes book and i havent had time to check the thermostat so see if that is what it is. but i can not find the temperature sending unit at all. i looked for quite a while can any one point me in the right direction to where it is. the book says it is on the front of the intake manifold, but i did not see anything that looked like the picture in the book.

also i got another question, while i was looking for the sending unit i noticed a wire that was not connected to anything, i could not find what it might plug into here are some pictures of it.





can anyone tell me where this wire plugs into?

my truck does not have a/c. i was thinking it might be a wire that would be needed if a/c was in my truck, but i didnt know. can anyone help.
thanks
Justin

TOYOTA 1

yea i think it is an ac wire.

nice truck!

norcalyota

thanks!
o and i forgot to say, but im going to be moving soon to the central coast california area around san luis obispo soon, so if there is anybody around there that wants to go wheelin. im going to want to go as much as my money allows, while trying to build up the truck.

abecedarian

The plug is for the knock sensor, IIRC.
You have 3 coolant temp sensors: one on top of the manifold, between #2 and #3 intake runners and two at the front of the intake manifold- one with a green plug and one with a black plug (IIRC) (actually right above the orphaned plug in your last photo). One is the cold start injector time switch (black plug, controls when the cold start injector operates when starting the vehicle) and the other is the ECU's coolant temp sensor (green plug IIRC).
The cold start injector time switch is circled in green and the ECU's coolant temp sensor is circled in orange, in the pic below:


If the temp gauge isn't about 1/4 up the gauge with the engine fully warmed up, the thermostat may be an issue.

norcalyota

ok so what does the knock sensor IIRC do? since it is not plugged in would that make a difference in the way the engine runs?

The thing is i dont know where it should be plugged into, i looked around for a while and couldnt find a home for it.

o the thermostat, well i do know how to take it out and everything, but is there a way to see if the thermostat is bad just by looking at it?

abecedarian

If you had a knock sensor, it would be plugged in. It would be a sensor on that side of the engine. What it does is "listen" to the engine and cause the ECU to alter the ignition timing if it "hears" detonation or pinging.

And you can't tell the thermostat is bad just by looking. You'd have to put it in some water and heat it up and pay attention to what temperature the 'stat opened and then let the water cool and note when it closed.
For what it's worth, the stock thermostat is rated 195F, give or take.

TOYOTA 1

hmm i thought that it was.. sorry for the wrong info. my 91 doesnt have ac either and i have that same wire not plugged in to anything.

abe, so your saying he doesnt have a knock sensor? is it a model/year thing? im confused lol.

abecedarian

I'm confused too. Neither Sin91's 91 truck nor my 88 4Runner have the knock sensor, and we're both Cali trucks.....
I'd have to look to make sure that connector is not for the a/c compressor (I have a/c on my 88)....

norcalyota

o ok so i probably dont have that knock sensor then.

well then i guess i will be taking out my thermostat next time i have some money to pay for a new one if it needs to be replaced.

thanks for the help

abecedarian

Well... not sure why an auto parts store would give you a 160F t-stat unless you asked for it.
Depending on where you go, some list 180-185 as stock and others have 190-195 as stock. Not a huge difference but the hotter the t-stat is, the better the vehicle will run (to a point).
160F is barely hot enough to let the computer go closed-loop mode, and 160F t-stat WILL cause the dash temp gauge to read erratic.

TOYOTA 1

the connectors might look different.

i think it is the ac connector, and im pretty sure that my 91 has a KS but im not sure(cant remember). i know this guy has one https://www.yotatech.com/forums/f120...e-nuts-183199/

and they list them for all efi years

scuba

That is a nice lookin truck !!1

RMA

Dude , You scored big time on that truck its NIce and clean .
Can I ask how much !!!

norcalyota

Thanks
i was pretty excited when i got to see it in person for the first time.
it was $3300 but...the truck did not registration, pink, smog, no nothin. but after smog and a butt load of signatures it was just under $200 for dmv fees and all

scuba

Since your gonna be in Slo, Check out the 09 Pismo Jamboree, Should be a blast !!

toyota4x4907

are you sure it isnt 1,059,343 miles? J/K That thing is CLEAN :O. I bought my '93 in '05 with 87K original and already had the metal timing chain guides done heh.
I'm fairly certain its just a "random" plug you found. I remember when I went looking through the engine compartment in my truck and there were 5 or 6 plugs that didnt go anywhere.

norcalyota

wow that jamboree looks like it should be fun! im for sure signing up
ive heard about those dunes and how much of a blast they are but havent been there yet


ha thats kinda funny you say yours had timing chain work done on it, cause mine has too. im not sure if the regular guides were put back in or the metal ones tho.

ive kinda come to the conclusion that it is probably a random plug also, it seems like ive looked everywhere and cant find a home for it.

now to start on the list of mods i have for the truck, just waiting on paychecks...

Justinlhc

I bet someone removed the thermostat. A guy I knew removed his(have no idea why) on a 22RE and his temp guage would never move. I'm guessing eventually sitting in traffic it might start to heat up.

Just a guess....

norcalyota

well the thing is that the temp gauge does move but only 1/8" at most, and randomly it will go up a bit higher or lower, but im going to check out the thermostat next time i get a chance

Justinlhc

Actually now that I think about it, I bet it's just stuck open. A truck that old with that kind of mileage had to have sat for a while. I'm guessing the thermostat is just stuck wide open. Looking at that truck and the engine bay I doubt anybody was messing with anything.