Hey out there, I was looking over the forums and noticed that most of problems were on the 22re engines. But I have a 5VZFE - 5 speed that will idle OK if I don't touch the gas after it's started and let it kick down by itself. However, if I drive down the road and then stop, the idle will bounce around a little and settle right around 1500 RPM. If I rev the engine to 4000 and let it go back down it will rest at about 1000 to 1100, and if I rev it to 5000+ it will rest at about 800 (proper idle to my knowledge). This has been going on for awhile and figured to clean out the throttle body, it was nasty, but it's clean now. After I did that the problem got even worse. I can actually press down on the throttle cable and it will idle fine, but as soon as I hit the gas, it will idle wrong again. Any ideas? I lubricated everything and checked it. I'm thinking it the vacuum that controls the fast idle, but it will kick up if I remove the vacuum line like it should. Any ideas?? I'm fresh out... Any help is appreciated!!! Thanks!!

 

When you remove that vacuum line form the dash pot the idle should go up. That is designed to hold the throttle slightly open for engine start and once it builds vacuum it pulls shut all the way. That is not your problem.

It is my guess that you have a problem with the Idle Air Control Valve (IAC) that is located on the under side of the throttle body and has that green plug on it.

I would take the throttle body off and then remove the valve from the throttle body. Clean it out really well and reassemble everything. It can get gummed up and make it not work right.

If this does not clear the problem there is a diagnostic you can do on it listed in the shop manual. If it does not check out OK you may need another one.

Also, make sure that throttle plate is closing all the way. There should be a little slack in the cable when it is all the way closed. If you have cruise control, check that cable also.

Gadget

www.GadgetOnline.com

 

Idle Air Control Valve - It broke on mine, easy to replace and cheap too

 

Mine's doing the exact same thing. When it's cold in the morning, I'll start it up, and it will rev at about 2000 rpm and stay there ever after it get's warmed up, which is quicker than usual since it's idling so high. Then once I put it in gear and I'm stopped, it will be idling at about 1100-1200 rpm. When I'm driving it will seem to drive fine, but when I'm coming to a stop it will go down to where it should be as soon as I let off the throttle, but immediately go back up 500-600 rpm as I'm slowing down, then right before I stop it will idle back up twice every time, almost like it's downshifting the tranny, which it's not doing of course. It's really weird. I'll have to check that out on mine, because I'm also having to add a lot of fuel with my SMT-6 to make it run too, so I might have other problems too. Man this sucks!

Chris

 

Ryan and Chris I would bet you both have the same problem. If you clean the throttle body regularly it is usually enough to prevent the valve from sticking (but not always). IAC would be my best bet as well for what is going on. Either disassemble and clean or replace......I would just get another if they are reasonable in price.

 

So is it the plug on the bottom side of the throttle body or is it the plug on the back-side of the throttle body that is the IAC?

Chris

P.S. A pic would be greatly appreciated!

 

I believe it is the light green part directly under the throttle body.
Christian has some good pics of it in his thread here:
https://www.yotatech.com/forums/show...=throttle+body

Here is one:


You can even see the air passage where it allows air to bypass the throttle plate.

 

Yeah, I thought it was the IAC myself, so when I cleaned the throttle body, I took that off and scrubbed that puppy down too. Maybe it's still gummed up, but I tried, I guess I will rip it off and scrub it some more. Breezey, you said the IAC was cheap, if you know where to get one cheap, please let me know. I was checking at Advance Auto and they wanted over $300! :pat: I really don't want to pay that much for a little piece of metal with a sensor in it. Please let me know where you got yours. Thanks!!! I will try cleaning the sucker again tonight. I'll post back and let you all know what's going on.

Thanks!

 

Might try testing the throttle position sensor (TPS). Since you said it got worse after cleaning the TB. The TPS can be damaged by cleaning the throttle body. A common cause of this is using throttle body cleaner in the throttle body without removing the TPS.

Here is a helpful link but I'm not sure how much of this applies to a 5VZFE engine. http://www.4crawler.com/4x4/CheapTricks/TPS/index.shtml

 

Yeah, I took off the throttle position sensor and IAC before I started cleaning it. I figured that stuff was bad to inhale, didn't want to know what it would do to plastic and electronic components. Hopefully it is just stuck and cleaning it will fix it.

 

Well today after reading this thread, I decided to remove the throttle body again, take apart the IAC and clean the hell out of it, put it back together and nothing changed at all, unfortunately. This is really pissing me off that I can't figure this thing out and my truck seems to run fine, except for idle and the fact that I'm having to add 12-13's across on the board on my SMT-6, which I should be at zeros. This absolutely sucks! I've sold all my stuff, the guy that bought it all is waiting to get my parts, and I can't take the SMT-6 off because without my truck won't run at all, until I find the problem with the idle and fuel first.

Anybody else have any pics of their engine bay that I can compare my hose connections with?

Chris

 

Are you going to be in the DC area anytime soon?

Gadget

www.GadgetOnline.com

 

Nope, but I sure would like to get this fixed, but I haven't had anough time to really review everything yet. It's so frustrating, especially since I've done this 4 times on both my 4runners, and this is the only time I've had any trouble like this.

Chris

 

Alright, well, I probably have the cleanest Throttle Body and IAC this side of the Mississippi. But, I still have the problem. I feel some of this a mechanical problem b/c I can push down on the actual slides that the throttle wire goes into and can make it go back down to idle. I think maybe the springs have lost some of their oomph. Anybody else have any other ideas? Or know where I can get my throttle body rebuilt? Thanks!

 

Maybe your throttle cable is hanging up.

 

Naw, the cable is fine, it will do it if I take off the throttle cable and the cruise control cable. They both had plenty of slack in the line to prevent it from hanging itself. If I 'blip' the throttle it will go back down to 1000-1100 from the normal 1400 or so. But that is still 200-300 higher than it should be. I am thinking about just finding a junk 96+ 4Runner and trying to buy a complete throttle body and IAC and TPS. Maybe give that a try. I think mine needs to be rebuilt, or atleast replace or tighten the springs on the butterfly dowel. I dunno, I hope I can fix this soon.. I am getting like 10 MPG...:cry:

 

Yeah, I haven't figured mine out either. All I know is it's a royal pain the butt not to know what's wrong with it.

Chris

 

Ryan, I really don't think that it is the throttle body causing the problem.
Do you have the ability to give us voltages from the TPS, MAF and O2 sensor?
Pull a plug and see if it is running rich.... so it could be a sensor.
If it is running correctly I would still bet on a vacuum leak.
Maybe use some carb cleaner to check for leaks (idle will dip if there is one).
Have you done any recent mods / work to your truck before this happened?


Chris, yours I am sure must have a vacuum leak somewhere after the MAF and that is why you are needing to bump up your fuel curve (to compensate for air that was not taken into account for by the MAF. Is the throttle body gasket on right? You should use a bit of carb cleaner and check for leaks as well.

 

Jamie,

I will get the voltages from the MAF and TPS tomorrow. (have to find a time where I can get dirty. ) But I have checked for vacuum leaks where I could, and found none. Nothing has been done to the truck before this happened, it just started happening, and then I went on the cleaning kick. It still will never idle back to 800RPM anymore, I can get it to about 1000-1100 if I hit the gas pedal and let it snap back. But other than that it stays at 1400-1700. It's voltage for MAF and cont. for the TPS right? Atleast, that's what my Chilton's book says... What about the O2 sensors? How do I check those? I really appreciate the opinions and help guys (and gals)!

Ryan

 

Oh, pulled a plug when I first started all the cleaning. They were nice and grey. Not wet or sooty or anything, burning clean to my knowledge.