Saturday, May 21, 2011

Toyota t100 throttle body to plenum hoses connections?

The system consists of a small air intake breather hose mounted in the intake tract before the throttle body, and the PCV valve, which is typically in the intake manifold or the valve cover. Air flow is from the breather before the throttle body, through the crankcase, up the PCV valve and into the intake manifold after the throttle body. It's basically a controlled air leak, with the PCV valve acting as a one-way check valve that has adjustable flow characteristics.

  1. Oil begins to be pumped into the air intake tube through the breather hose, upstream of the throttle plate.
  2. Oil runs down the intake tube into the throttle body.
  3. Oil sludges up the throttle body and throttle plate. Gas pedal starts to get sticky. Airflow reduced.
he PCV valve, located in a web of aluminum between the #3 and #4 intake manifold runners, under the fuel rail. The upper hose goes from that to the intake plenum. The lower hose

Well-hidden PCV

Wiggling other end of PCV hose to loosen it

A set of angled needle-nose pliers is essential to be able to grab the old PCV valve and pull it out of its hole in the lower hose.

Using angled pliers to pop old PCV loose

Now that the valve is popped out, then you can pull the other end of its upper hose off the stub on the intake plenum.
Finally out

And there's the hole that's left behind. That's the upper part of the lower hose.

Open PCV hole in lower hose

Here are the new parts I intended to install. The PCV valve is at the top of the pic, and the lower hose at the bottom.

New parts

remove the intake hose so the throttle body is fully exposed, but no matter how I wriggled my arm under the intake manifold, all I could do (if my arm was juuust so...) was touch the lower hose with my middle fingertip.

Looks like I'd need to remove at least the thermostat housing and the heater hoses before being even close to being able to pull the lower hose off the intake manifold and the oil separator box.

Bottom hose

Here's a picture of the intake manifold.

took the flathead screwdriver, and lifted the white snap-ins that hold this bundle of wires to the engine. It was blocking the middle bolt on the driver's side of the manifold from my ratchet.

A bolt here. Remove it to disconnect the bracket. After the bracket was removed, I put the bolt back so I wouldn't lose it! Also use it to loosen the bolt on the black air intake tubing, to remove it from the throttle body.

At the front of the throttle body on the driver's side, I disconnected two black connectors. You have to pinch them a little to remove them. The smaller on is on the bottom, and IIRC, you pinch it on the sides. The larger one has a one button on it, and press that down, and you can pull it out.

You can use pliers or your fingers to squeeze and pull back the hose clamps. After that, twist them back and forth a bit to break the "seal". After that it should slide right off.

There's a small rubber hose that runs from the throttle body to some sensors on the passenger side.

Under the throttle body is a small black hose. Disconnect this, again I used a flathead screwdriver to help me out. There's another hose similar to this on on the back side of the manifold. Take this one off too!

Step 8: This cable connects to the throttle. Take the lever and push it forward to loosen the cable (clockwise, standing on the passenger side). There should then be enough slack to fully remove it, by moving the cable out of it's feed, and pulling out the small anchor (that little cylindrical thing).
Step 9: Remove the 2 nuts from the top of the throttle body, and the two bolts at the bottom of the throttle body. If you want, remove the two coolant hoses (I wasn't particularly interested in cleaning the throttle body, so I left them on and just placed the TB out of the way. You should now be able to remove the throttle body for cleaning.
Step 10: Six 14mm bolts line the left and right side of the intake manifold. Remove these! Isn't this tough?!
Step 11: Underneath the throttle body area is a black bracket. Remove the two bolts faced upwards into the bottom of the intake's inlet.
Step 12: Here you can see that I've layed out all the parts in relation to the engine. From left to right: two bolts from bracket under the throttle body, two lower bolts from the throttle body, two upper nuts from the throttle body, two front bolts from the manifold, one small bolt from the bracket on top of the manifold, two bolts from the middle of the manifold, and two bolts from the rear of the manifold.
Step 13: Carefully remove the top of the manifold, it came right off for me. In this picture, you can see the thin metal gasket sitting on the bottom of the manifold. This is what you want to avoid damaging the most.
Step 14: Here's the top of the throttle body, hmm, not too dirty.
Step 15: Looking at the bottom, I'm pointing to the offending hole. This is the one that will require mass amounts of throttle body cleaner. It was totally clogged at the small end (see step below). When spraying the cleaner, protect your eyes and be careful! Also, I noticed that you should spray and wipe, as well as pour out the loosened liquid cleaner immediately. When I sprayed it, it would loosen the gunk, but evaporate quickly, and allow the carbon to redry onto the surface in a thin, hard to scrub film.
Step 16: Looking into the inlet of the manifold, you want to find this hole, roughly 4mm in size. It's on the right side of the tube. This is the other end of the hole. Of course, make sure to clean all other holes as well, the rest should be easy to spot by looking for the hoses that connect to the manifold on the outside.
Step 17: This one area had more carbon buildup then the rest of the manifold top alone! After cleaning and loosening the crud with throttle body cleaner, I started sticking Q-tips into pull out loosened buildup. This is a picture of the 4th Q-tip used! Still plenty of gunk! Since the hole isn't straight through, you can't really judge how clean it is. So I used a flashlight in a dark room, and stuck it in one side of the hole. If I saw a good reflection, I just assumed it was clean enough and the sides weren't covered up.
Step 18: At the matching hole for the lower part of the intake manifold, I sprayed a tiny bit of TB cleaner in and used a Q-tip. Cleaned as much as I could, but wasn't as effective as the top manifold. Some people warn not to spray in here, as the gunk will get into the engine. Others have said it only made their engine run rough for a few minutes afterwards, but it then went away. Your decision here. The TB cleaner didn't loosen it up enough for me, so next time, I'd probably just use a Q-tip alone.