4.0 1gre no power

When my O2 sensor went out it felt exactly like it was out of gas. It did throw a O2 code though so might not be your issue. I replaced the O2 and AF sensors and all is well.

 

ya problem im having is a bit different. i have brand new about everything engine bay related, and im still gettign readings all over the board on my scan tool. even with a piggyback ecm to manage it. i found the vacuum leak i think... but dont really know if it changed anything other then a little smoother idle

 

Sounds like you fixed the vacuum leak at least so that's good, no more unmetered air getting into the engine. That fitting is probably supposed to connect to something rather than be capped off so next step would be to figure out what should be connected to it or if it really is normally capped off. Also not sure if you did or not but I would reset everything to clear the codes and let it relearn idle and such, then see what codes come back. Big vacuum leaks like that can throw a large variety of codes that might not go away immediately on their own.

 

So the port was directly behind the pwm valve on the driver's side.of the intake.manofold. I couldn't find anything on routing of vacuum lines connecting to it. But I would bet if someone had a second gen they could take a peek and see if theirs is connected to something or just capped off

 

I can check later when I get out of work, someone else might beat me to it though. A picture would probably be helpful if you can get one and post it.

 

I’ll be installing new VVT solenoids on Thursday if you don’t have a better pic by then

 

So that goes to the valve cover? So I should run a hose there huh lol

 

Looks like it . Fingers Crossed

 

I wonder if that would effect performance though. Doesn't seem like a necessity to be hooked up to run correctly?

 

My guess is yes it could affect performance but I am just a back yard mechanic and have never come across this issue so I cant be 100% sure. Sorry man . Maybe someone with more knowledge will chime in .

 

Pretty sure that connects to the PCV valve on the valve cover with a hose.

 

Will it effect performance of the truck? I'm still trying to figure out what's going on with my truck and the wierd readings I'm getting are killing me slowly and painfully

 

It will be a massive vacuum leak if it's not connected.

 

I plugged it with a cap to stop the vacuum leak. I wish I understood fuel trims and stuff to grasp what's going on with this thing haha the fuel trims are good then they drop out over and over like it's out of time but I've had the timing checked twice and know it's good.

 

Update. Ran new vacuum lines back to pcv valve and drove the truck. Still bank too lean on 1+2 sprayed entire engine bay with starter fluid and no rev. Idle is rough but it's jumping fuel trims around up and down like a banshee. Any clue on where to go next would be greatly appreciated. I feel like I'm so close to having it good to go engine wise but im just shy of it. Fuel pressure was good to the rail, injectors have been cleaned professionally, vacuum leaks have been sorted, restarted ECM and let idle for an hour to tune, still idling rough and fuel trim is bouncing.
Please send help lol

 

My bet is further vac issues somewhere. Plug off/test possible internal leaking items like power brake booster
Possible throttle body needing cleaned.
Clear codes

 

Rereading this thread the leak seems to focus on pcv valve. Pcv valve is just a controled vacuum leak. They can and do wear out and or fail open or shut. Is it new also? Is it O.e.m. or a trusted quality brand?

From the pictures you seem to have replaced every conceivable part you can, like probable high quality factory hoses with sometime questionable. Low quality fancy euww and awww red look at me aftermarket are a possible leaking point.

Even an exhaust leak or blockage can create fuel rich/lean balance issues.

 

everything motor wise was made by URD, including intake, and exhaust, so its not low quality of any form. everything in motor is brand new and either made by toyota, URD, molnar, or LCE, nothing but electrical and sensors are original or factory

 

my fuel trims are jumping almost 180 degrees on a constant basis. i fixed all the vacuum leaks and it has a lot more power but still has bank lean codes on both banks as well as a rough idle. so still something wrong with it outside vacuum leaks.