[gamefreakgc]

Originally Posted by ShakenBake

The bypass valve actuator should be delivered Monday.

I checked the coolant sensor, which was connected. I also re-plumbed the power steering vacuum lines per the Magnuson directs for the T100.

On a sorta unrelated note, I bought two catch cans to install, one for the PCV and the other for the CCV. When installing the SC in noticed some brown gunk in the CCV line coming into the intake tube. The engine end of the line was split pretty bad as well.

I highly recommend replacing the PCV valve if it's starting to spew oil into your intake. It might be stuck open slightly. Use only an OEM PCV valve, I've gone through 2 parts store ones in 4 years. They don't seal well and caused a bad idle condition.

It's interesting about the catch cans and how it varies. Some people have it catch oil and clean up the intake. On mine, it was full of water and only caught condensation which is harmless.

[ShakenBake]

Originally Posted by ShakenBake

The bypass valve actuator should be delivered Monday.

I checked the coolant sensor, which was connected. I also re-plumbed the power steering vacuum lines per the Magnuson directs for the T100.

On a sorta unrelated note, I bought two catch cans to install, one for the PCV and the other for the CCV. When installing the SC in noticed some brown gunk in the CCV line coming into the intake tube. The engine end of the line was split pretty bad as well.

Update

The bypass valve actuator was delivered today and is installed and connected via vacuum hose. I also installed a brand new throttle body gasket.

The engine still won't idle and will not run consistently.

Is it something with the fuel regulating valve? Trims way too far off? I'm running outta ideas here.

[4Reak Show]

You could put the old intake back on and see what happens to for sure rule out the supercharger or not. I'm willing to bet something is sticking with the IAC even tho I think you said you cleaned it.

[ShakenBake]

Originally Posted by 4Reak Show

You could put the old intake back on and see what happens to for sure rule out the supercharger or not. I'm willing to bet something is sticking with the IAC even tho I think you said you cleaned it.

Is there anyway to check the IAC? In my check, re-check, re-re-check procedure I confirmed it would only allow air from the TB to flow INTO the engine. Isn't that counter intuitive though? That's the only "vacuum" line that flows OUT of the intake.

[4Reak Show]

Originally Posted by ShakenBake

Is there anyway to check the IAC? In my check, re-check, re-re-check procedure I confirmed it would only allow air from the TB to flow INTO the engine. Isn't that counter intuitive though? That's the only "vacuum" line that flows OUT of the intake.

There's tons of 3rd Gen IAC cleaning write up. I'm not talking about the tiny check valve you're supposed to install in the air assist line. That wouldn't cause your symptom. It just seems like your engine isn't holding an idle, which is what the IAC controls. It's common to have this issue after a battery disconnect on a tired/dirty IAC since the computer has learned to compensate. And with battery disconnected it resets but is unable to baseline since the passage remains closed.

Any way, basically you remove the AIRAID intake tube. Then you remove the MOTOR portion of the IAC with 2 screws. I always used to leave the actual valve installed since this keeps you from having to drain the little coolant hoses that feed the valve. Removing the motor portion on its own allows access to be able to turn the shaft from the motor end and then clean the actual valve portion just inside the throttle body. For a test, after the screws are removed and the electric part is taken off, you can very gently turn that shaft by finger tips. (It only rotates like 90 degrees or less total so don't force it.) but you will feel a sticky part from carbon build up. That will prohibit the valve from opening enough to allow the engine to idle. That sticky part needs to be cleaned. It needs to be smoooooth as butter.

Do a forum search for IAC cleaning for a more detailed write up. It's a free easy idea to cross something off the list. Post pictures if you have questions. These 3.4's are about as simple an engine as they come.

Edit: I just watched Tim's video and it was good but unnecessary to do that much work. Like I said above, remove intake boot, remove 3 pin electrics plug that juts out from directly under throttle inlet. Behind that is the electric motor portion of the IAC valve with 2 screws. You want to be careful and apply a lot of force so you don't strip out the screw heads. Once those screws are out, the white (or black) motor piece pulls straigh off. It's somewhat magnetic so it sort of sticks. Behind that is the tiny shaft I reference. That shaft spins to actuate a small air bypass in the throttle body. You will see the passage just inside the throttle inlet, before the throttle blade. Squirt a little brake cleaner in that hole and manually spin the valve shaft back and forth a ton until it rotates smoothly. Reassemble, fire it up and let it relearn a bit. Then go do some donuts.

[ShakenBake]

Originally Posted by 4Reak Show

There's tons of 3rd Gen IAC cleaning write up. I'm not talking about the tiny check valve you're supposed to install in the air assist line. That wouldn't cause your symptom. It just seems like your engine isn't holding an idle, which is what the IAC controls. It's common to have this issue after a battery disconnect on a tired/dirty IAC since the computer has learned to compensate. And with battery disconnected it resets but is unable to baseline since the passage remains closed.

Any way, basically you remove the AIRAID intake tube. Then you remove the MOTOR portion of the IAC with 2 screws. I always used to leave the actual valve installed since this keeps you from having to drain the little coolant hoses that feed the valve. Removing the motor portion on its own allows access to be able to turn the shaft from the motor end and then clean the actual valve portion just inside the throttle body. For a test, after the screws are removed and the electric part is taken off, you can very gently turn that shaft by finger tips. (It only rotates like 90 degrees or less total so don't force it.) but you will feel a sticky part from carbon build up. That will prohibit the valve from opening enough to allow the engine to idle. That sticky part needs to be cleaned. It needs to be smoooooth as butter.

Do a forum search for IAC cleaning for a more detailed write up. It's a free easy idea to cross something off the list. Post pictures if you have questions. These 3.4's are about as simple an engine as they come.

Edit: I just watched Tim's video and it was good but unnecessary to do that much work. Like I said above, remove intake boot, remove 3 pin electrics plug that juts out from directly under throttle inlet. Behind that is the electric motor portion of the IAC valve with 2 screws. You want to be careful and apply a lot of force so you don't strip out the screw heads. Once those screws are out, the white (or black) motor piece pulls straigh off. It's somewhat magnetic so it sort of sticks. Behind that is the tiny shaft I reference. That shaft spins to actuate a small air bypass in the throttle body. You will see the passage just inside the throttle inlet, before the throttle blade. Squirt a little brake cleaner in that hole and manually spin the valve shaft back and forth a ton until it rotates smoothly. Reassemble, fire it up and let it relearn a bit. Then go do some donuts.

Thanks for the help, I should have searched before asking. I watched most of Tim's video last night and your suggestions seems to make more sense for my purposes. I will clean and asses the IAC this evening and report back.

[ShakenBake]

Originally Posted by gamefreakgc

I highly recommend replacing the PCV valve if it's starting to spew oil into your intake. It might be stuck open slightly. Use only an OEM PCV valve, I've gone through 2 parts store ones in 4 years. They don't seal well and caused a bad idle condition.

It's interesting about the catch cans and how it varies. Some people have it catch oil and clean up the intake. On mine, it was full of water and only caught condensation which is harmless.

I'll take a closer look at the PCV but I did change it just last year. That said, I didn't notice too much junk coming from the PCV, it was the cam cover vent where I saw some brown gunk when installing the SC.

[gamefreakgc]

Originally Posted by ShakenBake

I'll take a closer look at the PCV but I did change it just last year. That said, I didn't notice too much junk coming from the PCV, it was the cam cover vent where I saw some brown gunk when installing the SC.

I don't know all the inner workings of the 5VZ-FE, but my old engine used to do that too. The hose was lined with oil varnish and the intake tube had oil stains the whole way through. I parted out an older engine where it was so bad, the ridges of the intake tube were actually filled with oil and it has spilled and soaked into the air filter!

My low-mileage JDM engine is as clean as a whistle. I know it has to do with blow-by gases and oil vapor, I wonder if there's a correlation between engine health, compression, and oil coming through the vent hose. My old engine was not in good shape before it blew.

[ShakenBake]

So I cleaned the IAC via "easy method", which I highly recommend to anyone as a solution before diving deeper and removing coolant lines and removing the entire TB, and got some black chunks coming out the hose fitting at the bottom of the IAC.

I video scoped the IAC valve visible from the throttle body and it looked way cleaner and the IAC valve actuator moved a little smoother but not hugely different.

Then I noticed the IAC hose check valve wasn't working as it should. It didn't block flow into the TB and restricted flow leaving the TB. I cleaned that check valve and it seemed to be working a lot better than before but still seemed a little restrictive compared to just blowing through a 3/8" hose. Regardless, I reconnected it all and tried again and it seemed like it wanted to idle more but would still stall at idle. A couple of times it was about to completely stall but came back to life for a brief moment. It didn't seem to do that before.

Next, I deleted the SC IAC check valve completely and got marginally better results than the cleaned AC IAC check valve but it still does at idle.

I also did a resistance test on the IAC valve actuator and it was just shy of 22 ohms which is in range per the FSM.

I'm gonna try a more thorough IAC cleaning.

Any other ideas? Anyone live near western PA or know a good Toyota mechanic that does?

Edit: Here are some data from my Bluetooth OBD reader that I took last night when trying to run the engine after cleaning the IAC and messing with the SC check valve on the IAC hose. Is anyhing in this limited data set helpful if figuring out why my car won't idle?

[ShakenBake]

Ok, so I disconnected the MAF wiring harness and it idled. Rough, but it idled.

What are the implications of taking the MAF sensor out of the equation?

Here is the video of it idling like crap: YouTube

[ShakenBake]

Here is the OBD log of it idling with the MAF wiring harness disconnected and the a link to the screenshot of the codes it threw after running a little longer. It gave me a P0100 MAF circuit and a P0110 intake air temp malfunction, which isn't surprising or particularly useful.

Dropbox - Screenshot_20200605-203120.png - Simplify your life

[MarkamisPrime]

Originally Posted by ShakenBake

Ok, so I disconnected the MAF wiring harness and it idled. Rough, but it idled.

What are the implications of taking the MAF sensor out of the equation?

Here is the video of it idling like crap: YouTube

Have you tried spraying brake clean over the area that may have a vacuum leak?
Or try unplugging your TPS ?
It sounds like you have a massive vacuum leak.

[ShakenBake]

Originally Posted by MarkamisPrime

Have you tried spraying brake clean over the area that may have a vacuum leak?
Or try unplugging your TPS ?
It sounds like you have a massive vacuum leak.

I haven't tried the brake cleaner/carb cleaner test yet. Until yesterday I couldn't get it to run long enough to try.

I'm gonna check for a vacuum leak today.

What would unplugging the TPS tell me?

[MarkamisPrime]

Originally Posted by ShakenBake

I haven't tried the brake cleaner/carb cleaner test yet. Until yesterday I couldn't get it to run long enough to try.

I'm gonna check for a vacuum leak today.

What would unplugging the TPS tell me?

My truck was idling like crap too and then would die
After doing all the basics
Cleaning maf and iac checked for vacuum leaks
I even replaced the iac
And nothing
Turns out my tps was bad telling the ecm I was flooring it at idle
So it was flooding itself until it would die.
Unplugging the tps will essentially bypass it
After I unplugged the tps the truck idled fine
I didn’t bother to ohm the old sensor out or anything
Just to triple check I plugged the sensor back in while the truck was running and it immediately started stumbling again.

[ShakenBake]

Originally Posted by MarkamisPrime

My truck was idling like crap too and then would die
After doing all the basics
Cleaning maf and iac checked for vacuum leaks
I even replaced the iac
And nothing
Turns out my tps was bad telling the ecm I was flooring it at idle
So it was flooding itself until it would die.
Unplugging the tps will essentially bypass it
After I unplugged the tps the truck idled fine
I didn’t bother to ohm the old sensor out or anything
Just to triple check I plugged the sensor back in while the truck was running and it immediately started stumbling again.

Well this is embarrassing...really embarrassing, but problem solved. Yesterday, my buddy and I removed the SC to make sure it was properly seated and that no hoses or wires were pinched beneath it. After staring at the intake-less engine for a half hour and running out of things to check, my buddy noticed the giant vacuum leak culprit. The used SC I purchased was missing the two bolts and plate that covered the 7th injector port located just downstream of the throttle body. We plugged it and it fired right up. I can't believe I missed that. I checked the hoses and gaskets 15 times and never saw it. Anyone know what parts to get to properly seal it off?