Q: What's the benefit of this, or in other words, why should I bother? A: The straighter T-body should increase the speed that air will flow to the combustion chamber (a good thing) this also allows you to remove the air flow valve, which is used to control the cold air idle speed. FrankenYota explains why this is a good thing: The new style uses a bimetallic spring attached to an air (vacuum) valve to control cold idle speed. When the spring is closed (cold) the valve allows extra bypass air past the throttle plate to increase idle speed, as the coolant flows past the spring and starts to heat up it moves the valve to gradually decrease idle speed. There is no electric IAC motor to fail in this system, in fact since it is 100% mechanical there is really nothing to degrade or fail. The older style AFV has an electrical connector that uses a heating element to accomplish basically the same thing. Personally my electrical connection to the air flow valve was broken, dumb newbie me yanked on it and broke the plastic, so it constantly fell off and caused the idle to surge. I was tired of duct taping the damn thing on so there were no tears when I was finally able to scrap it. This swap also lets you easily remove the redundant throttle linkage which is just an overly engineered piece of crap anyway, simple is good. And finally, admit it...it looks much better that and chicks dig the custom engine mods. Q: What parts do I need to grab from the late-model donor? A: Upper Plenum, and throttle body. Throttle cable the newer is shorter than the older cable. The air intake elbow pipe connects the throttle body to the plastic pipe that connects to the air box. You will need to swap over your throttle position sensor (the plugs are different) and the metal pawl hidden behind the TPS on the new T-body, so you don't have to grab the donor's TPS. Does it matter if the donor is 2wd or 4wd Pick Up or 4runner? A: No, they're all the same as far as I know. I got my parts from a 93 2wd PU for my 85 4Runner Q: Will I need any other parts? You will also need some hot water hose, which you can yank from the donor or any parts store (5/16" approx). Gaskets: Those include throttle body (22271-35020) EGR (25628-35020) middle intake (17176-35020) and cold start injector (I have to look it up and I'm lazy) You may also need a vacuum plug if your throttle body has 4 vacuum ports. Some small hose clamps might be needed as well. Q: Where should I get these parts? A: Junkyard for everything but the gaskets, a Toyota dealership for the gaskets. Q: Should I clean all the black thick goo out of the new T-body? A: Absolutely, a clean engine is a happier engine, and happy engines create more power. Q: What should I use to clean it? A: Engine degreaser and some elbow grease works wonders. Q: What about my injectors? There are no issues with the injectors for the swap, however I'm including this because it is a good idea to get yours cleaned and flow tested while you are in there. Don't waste your money on new ones, a good rebuild is all that most need. Q: What will I have to modify to make this work? A: Not much, the bolt patterns are the same, and most of the connections are the same. I had to re-route some coolant hoses and some have had to bend the cold start injector to get it to line up. My free advice, study the t-body while you are cleaning it, and learn where everything needs to go Q: Can I paint it? A: Yep, I didn't but I've heard that model paint or engine paint works well for that extra bling-bling effect Q: Where is the air flow valve located and what does it look like? A: Just in front of the oil filter, below the lower plenum behind the AC compressor. Pic Q: Is this SMOG legal? I passed with it in California, so as far as I know there is no problem with smogability. Q: What about over-bored t-bodies? A: This is a somewhat common mod for more air flow and thus more power. My wallet was not in a giving mood and thus I didn't opt for this, but I have heard good things about this. LC Engineering T-body plunge bored 3.5mm larger than stock, than it is taper bored to 4mm oversized. Max-Bore quick turn-around over-bored t-bodies.  So after years of wanting to do it I finally had the throttle body and upper plenum over-bored. I went with the Max-Bore option as the cost was much lower than LCE's. So far the difference in power isn't very noticable, however the throttle respnsiveness is much much quicker. I no longer get that annoying "lunge" at low speeds when I step on the skinny petal. Well worth it. Q: Any other advise? Just a tip, while you have your upper plenum apart stuff some rags in the intake ports, that way if you drop a washer or nut or something else it won't go into the combustion chamber and destroy your engine when you fire it up... Links: Jon "Pappy" Stewart The person I stole the idea, and part numbers from from...but it was out of love Back to Tech |
