Throttle Body Baseline (1 Viewer)

[azcromntic]

It's time to tear into my throttle body and clean it up. Plus, I want to change some of the hoses underneath the upper air intake. Here we go.

Step one:

Step two, take the air filter cover, air hose and pcv hose off:

Step three, take off the two egr vacume hoses, label at least one of them.

Step four, unhook the two connectors, the single vacume hose and the fuel return hose.

step five, take off the throttle, air and shift cables. There is a little nub at the end of the cable that goes into the hole shown (kind of blurry). Just rotate the cam (like I am doing with my thumb), slightly pull the cable toward you and then push to the right side where the groove is.

 

[azcromntic]

Step six, mark the nuts on the passenger side of the cables to mark their position and then losen the nuts on the drivers side of the cable and lift the cable free. The ones in the picture are the ones to losen. Mark the position of the nut that is on the other side of the metal plate before losening.

step seven, take off the first bypass hose. You can see the metal line with yellow goop. I took the hose off of that.

step eight, take the four bolts out that mount the throttle body to the upper air intake. Note: The long bolts went on the bottom.

 

[azcromntic]

step nine, seperate the throttle body from the upper air intake, slip the gasket out if you want. Be sure to catch the lower mounting bolts! Then, with your pliers, take off the second bypass hose.

step ten, look around at all the crud, say "oohhh man..." and then take some pictures.

 

[azcromntic]

Seems as though I am missing a piece of the shift cable that attaches it to the spring loaded cam.

I'm fairly certain the little nub didn't come off while I was working on it yet it shifted fine when I drove it last. Can the transmission shift even if this cable is not hooked up? Is that even the shift cable (it runs down the tranny tunnel)? Cruise control?

 

[azcromntic]

Here is hose I was wanting to change. My screwdriver is touching it.

Is that hose just regular fuel hose or is that some special hose I have to order from Toyota?

 

[scrowley]

looks pretty clean in there. Mine was all black before I cleaned it. I would say if there in no sharp bends in that vac hose I would just go buy a piece of hose the same size at your local parts store. Cheaper.

 

[azcromntic]

It's a 90 degree bend. I'd love it if I didn't need a preformed hose! I just want to know if the original was a preformed hose with a 90 degree bend in it.

 

[azcromntic]

Finally got everything back together. There wasn't anything peculiar to take pics of. The throttle body was pretty clean. I tested the TPS and IAC and replaced an o ring. I also replaced about 5 feet of vacuum hose, bypass heater hoses. The fuel hose I replaced (in pic above) was a PAIN! I also cleaned out a bunch of gunk from several of the holes on the upper plenum. Only problem now is that it is showing code 71.

I haven't had the chance to go back over to see if a vacuum hose fell off somewhere or not. I speculate i have more cleaning to do in the big egr passage of the upper plenum. Could i just take the bottom hose off the proportioning valve attached to the back of the plenum and blow air through the valve and passage at the same time?

 

[Hoosier Daddy]

Were you having the code 71 before the cleaning too?

 

[lt1fire]

Maybe I missed it but what did you clean it with??

 

[azcromntic]

Were you having the code 71 before the cleaning too?

No. No code 71 before.

 

[azcromntic]

Maybe I missed it but what did you clean it with??

Throttle body cleaner. I did not spray it on the TPS or IAC. I used a drill bit to clean out passage at the top of the plenum but couldnt clean around the corner it makes. I sprayed throttle body cleaner through ports p, r, e on top of throttle body and used a drill bit to clean out little port on bottom of valve that is attached to egr via one vacuum hose. Other than that i just cleaned with blue rag with throttle body cleaner sprayed onto it.

 

[azcromntic]

I pulled the efi relay this morning for 30 seconds and started it up. Check engine light was still on. I'll have to do it again and check the code; could be more than one.

I'll also have to check and see if I have the little orange and black "thing" located under the throttle body turned the right way. Here is a picture of what I am refering to:

The "proportioning valve" I mentioned earlier (I don't remember what it is actually called) is pictured here with the green writing (not blue top).

It has a small port on the bottom that hooks to the egr (blue top). The little port and hose were blocked and so I replaced the hose and cleaned out the little port on the "thing" with the green writing. I cleaned it with a drill bit. After the code came up I ran some throttle body cleaner into that port and into the egr ports. The only port I didn't get to clean that well is the port that the "thing" with the green writing on it goes to in the upper plenum. Could i just take the bottom hose off the "thing" with the green writing attached to the upper plenum and blow air through that to clean out the passage?

 

[muddinmetal]

I would be real hesitant to do that, inside that thing (the actual egr valve) is a diaphragm, I believe any real air pressure would ruin it

 

[azcromntic]

Okay, so I have been thinking of them wrong. I thought the one with the blue top was the egr. The one with the blue top is something to regulate when the egr opens or not. (That's sort of a statement and a question).

So basically I'd have to take the egr valve off and blow air into the upper plenum where the egr attached. Getting that big bolt off the egr tube might be a fun experiment. I'll have to search on some tips for that.

I've done all this so far without taking off the upper plenum and hopefully I won't have to.

 

[BlueCruiser84]

What is code 71?

Yes, the valve is the metal saucer and the blue/brown thing is the regulator.

To test them I'm pretty sure all you need is a piece of hose and your mouth. Hook the hose to the correct ports (I don't recall which is which) and apply vacuum. If the vacuum holds then the diaphragms are ok.

-There is a good chance that the passage in the plenum is clogged with carbon
-Did you remember to hook up the EGR temp sensor? If it is a 93 you may not have it.

 

[azcromntic]

What is code 71?

Yes, the valve is the metal saucer and the blue/brown thing is the regulator.

To test them I'm pretty sure all you need is a piece of hose and your mouth. Hook the hose to the correct ports (I don't recall which is which) and apply vacuum. If the vacuum holds then the diaphragms are ok.

-There is a good chance that the passage in the plenum is clogged with carbon
-Did you remember to hook up the EGR temp sensor? If it is a 93 you may not have it.

EGR system malfunction (I found my FSM)
Could be:
Egr valve
egr hose
egr gas temp sensor circuit
egr gas temp sensor
vsv for egr
Vsv circuit for egr
Ecm

It also says:
60 seconds after startup of egr operation egr gas temp is less than 158F and the following occurs:
engine coolant temp is 127F or more
1200 rpm or more
intake air temp is 32F or more

Two trip logic

A short drive in cold weather, followed by a second trip a few minutes later could cause that. My first step will be to clear the code and drive again (at least twice)

The check valve is in correctly

 

[azcromntic]

The code came back after driving it. So, I took the egr and regulator off. The regulator was nice and clean. The egr temp sensor showed 43k ohms with temp at about 160F. The big port in the plenum had a small amount of carbon in it but air blew through easily. The egr didnt have the build up I thought it might have. The diaphram was sticking though so I cleaned it until I could exercise the diaphram easily. I cleared the code again.

We'll see tomorrow if the code comes back again.

 

[azcromntic]

Here's some pics I took. EGR is easy to take off. Just make sure to take the studs out. I didn't have the correct socket so I just used a 5mm socket. The studs are not in there very tight: I used a 1/4" ratchet to take them out.

I used a screw driver to move the metal ring (shown through the holes on case of egr) to open and shut the egr. Before cleaning the egr it was difficult to move it. Once cleaned it would move easily. I drove it a while today and the code has not come back yet. Hopefully I can move on to other things now.

 

[azcromntic]

Check engine light came on again this past weekend. I haven't pulled the code yet but I know what I suspect it is.

I did check the temp sensor while I had the EGR off and it was good. I cleaned the EGR so that the little diaphram thing would move easily.

I wonder if there is a way, and if that way is safe, to have the EGR valve suck seafoam or something through the upper manifold to clear out gunk. ???

Just a thought.