Engine coolant temp sensor unplugged

I did when I was getting ready to pull the engine for the rebuild and there wasn't anything in it.

Right now I have the little tube off that goes from the fuel pressure regulator to the tube that runs to the airbox and there is no change in how it's running. It's idling perfect. That seems odd to me so whats the point of the vacuumed line?

 

Right or wrong I ended up splicing a switch into the ects wiring harness. When I switch it off in the temperature areas it had the hard starts before, it now starts right up and as soon as it starts I switch it back on and the computer then reads the correct data. It does throw a check engine light but id rather have my light on than work my starter and everything as hard as it was before. After 2 years of messing with it and having it at multiple shops with no luck this is my fix

 

You never mentioned how this issue started.

It's just a reference port for the regulator, any change in pressure or vacuum at that port will change the fuel pressure. Every Toyota regulator I've seen is referenced to atmosphere unlike most domestics that are referenced to manifold vacuum.

I guess if it works for you, I'd still want to find the root cause.

 

Believe me I'd love to actually know what's wrong, but after 2 years of tearing the whole thing apart over and over and putting tons of money into it im done. It's either that or taking a sledge hammer to the entire truck would feel so good.

 

Feeling your pain Bowhunter
Jeez

No codes….ever?…..b4 the splice?

 

None besides a cylinder 6 missfire which was the really low compression and why I pulled the motor for a rebuild. I can't think of ever getting a sensor code since I've owned the truck besides if I forgot to plug one in when I was putting stuff back together. I did have one for something on the charcoal canister once but it was just a line that had come off. After putting it back on have never had that code again.

 

Hmmmmm

Just guessing….only bc I have experienced

Trying to stab an engine in with friends, smashed a harness and sensor on fire wall bc of inexperience
Wouldn’t start….plucked motor again and saw our idiocy work

u inspected the harness that runs the ECT?

 

Just to where it goes into the plastic with the rest of the wires. Didn't seem like there was any obvious issues. Is there only the 3 grounds on the truck?

 

Yeah man…..just shot in the dark

shit
Seems like you have all the ‘Hot no Start’ causes covered (and u know what you are doing)
Fuel pressure good?

 

Fuel pressure was good right before we pulled the motor. I havent checked it lately since these trucks are such a pain to but it was doing this same thing before pulling the motor and outside of that temp range I havent had a issue of it cutting out or anything. It does act fuel related but it's like the computer is telling it to not give enough fuel. It's a long shot but I'm going to clean every where there is a ground tomorrow. I know on my diesel if a battery post gets corroded my transmission goes crazy so weird things can happen with something as simple as a dirty ground I guess haha.

 

Thats a bitch man.. i had a 2.7 i got with 60k for cheap in a reg cab 4wd an it had sat for 8 yrs.. fought this 3rz for years tryn to get it to run 100% like it should have being pratically new!!
i replaced the clogged cat.. injectors whole fuel system every filter and hard lines, tank..and so on. Damn ethanol... finally was running semi normal.. Thought all was well but It wud be hard to start cold. Had to give gas then once started it would not rev over like 2500. it acted just like a 2 stoke dirtbike that bogs at idle you gotta rev it to clean it out.. so id get to end of my small rd. an it revved thru to 4500 rpms an cleared out.. every morn to work for a while... then it would run fine throught the whole rpm range. It ran ok warm but wud act sluggish sometime..finally think it was some evap thing. And the computer had gotten wet.. making it act odd.. sitting aint good.
sad thing was i had finally got it running without a cel an running right and it juat blew one day randomly at like 138k rod knock.. i hated it so much ive boycotting in my corner yard for a long while but its 5vz bound or the right diesel wud also be nice...def good u found that wire to cut off cuz u def dont want it hurtin ur good engine or ur starter.. be nice if you cud swap the ecm out from a buddy...cud be a ground or broken wire sounds like youll get it eventually. If not sounds like ur fix works pretty good...

 

Man they never end! Haha if I ever do have to swap the motor again I think ill bite the bullet and probably buy a new wiring harness while it's all torn apart (I really don't want to swap the motor ever again). Hopefully yours will be good to fo after the swap!

 

Hey BowHunter, I was curious if you had any luck on figuring out the issue. My coolant gauge isnt reading either but the sensor is giving me correct temp reading while using a scanner. Hoped it was a bad Instrument cluster but had no luck.

 

Yours sounds like it's just the little sensor on the back of the intake manifold. That's a easy fix. If you take off your upper manifold it's easy to get to. Or it could have came un plugged l. It's a tiney connector.

 

I have the 2.7 L 4cyl, would it still be in the same spot? And do you know what the name of that sensor is called so I know what I’m looking for ?

 

2012 does not use separate sensors, it has 1 sensor that reports to the PCM and the PCM sends the temp signal to the instrument cluster via the CAN bus.