2nd Gen 5E-FE Throttle Body Upgrade
Written by: t+combo
I found today that a 1994 Corolla throttle body will fit on a 1995-1996 2nd generation 5E-FE. The 1997+ 5E-FE's use a different throttle body so it is not easily swappable unfortunately. I would say that this is worth doing as a Corolla throttle body can be got at a junkyard for next to nothing, and it is a fairly simple procedure to install. The Corolla throttle body has a 50mm bore and the 2nd gen 5E-FE has a 45mm bore.
Here is a rough comparison. The Tercel throttle body is on the left.
The throttle body I got, I am not aware exactly of the engine code of what it came off, but it was a '94 Corolla. The thing that persuaded me to see if it would fit was that it was VERY similar to a Tercel's throttle body. It has the same vacuum ports on top, and it turns out it has EXACTLY the same throttle position sensor (TPS), and the idle air control valve (IAC) is similar and will work (I tried it, it does work). MAKE SURE YOU ALSO GET THE 2 BOLTS FOR THE THROTTLE BODY, AS THE 2 BOLTS FOR THE COROLLA THROTTLE BODY ARE LONGER, AND YOU WILL NEED THEM. ALSO GET THE GASKET, AS IT IS METAL AND YOU WILL NEED IT.
Now, the first thing to consider is that this throttle body does not have the vacuum provisions for the power steering. Without those vacuums, I do not know how much difference it would make in your power steering system, but you will have to go without those lines unless you draw vacuum from another source, so consider that.
OK. Here is the procedure:
Basically, you just take off your intake/intake system (stock or aftermarket) so you have access to your throttle body.
Disconnect the vacuum lines and make sure you have the vacuum chart sticker on your hood, so you know where they go. If you don't have the sticker make sure to label where they go.
Unplug your throttle position sensor and idle air control wiring.
Unhook the throttle cable by pulling the throttle all the way open, and sliding the cable out.
Undo the 4 12mm bolts/nuts, and pop off the throttle body.
Now get a pair of pliers and undo the clamps for the coolant hoses to the TB. Move them down the line so they are out of the way. Get the pliers on the hose, and twist the part that's over the port till it breaks free. Then, pull the hoses off.
The vacuum lines to the power steering may be difficult to get off. If you won't be using them, just cut them and pull them off the power steering racks ports and discard. You will no longer use them. If you are reusing them, remove them and place them to the side.
Now, you should have the stock throttle body in hand. Take the throttle body gasket off the intake manifold. Scrape the surface clean if necessary, but be careful as the surface is aluminum and scratches easily.
Now get some vise grips and remove the 2 studs for the throttle body on the intake manifold. These will no longer work as they are too short, and you'll be using the Corolla bolts.
Now might also be a good time to check your exhaust gas recirculation (EGR) port in the intake manifold. After time, this will clog throwing an "insufficient EGR flow" code. The port clogging is the cause of the code. It is caused by carbon/oil buildup. If you want to clean it, feel inside the manifold to see if it's clogged. If it is, just get something like an allen wrench and scrape it clean and make sure you get all debris out of the intake. This will save you trouble down the line.
Now you have both throttle bodys. You may notice that the Corolla throttle body has a vacuum actuator on it that works with the throttle cable bracket. Remove this, it will not be needed. The easiest way to remove the philips head screws is to get a pair of vice grips and lock them perpendicular on a philips screwdriver so you have more leverage. The vacuum line that goes to the actuator can be plugged now, it will not be used.
Get a pair of pliers and spin the vacuum ports on top to the same position as the Tercel's throttle body. You can either, leave the idle air control valve that the Corolla throttle body came with and plug the vacuum port on the bottom, or you can swap your Tercel idle air control assembly on via the 4 philips head screws.
Now you will have to use your stock throttle cable bracket on the Corolla throttle body. Undo the 12mm nut and remove the bracket from the Tercel throttle body. Remove the corolla bracket.
The Corolla throttle body also has an inner bracket built in to the spring assembly. You will see if you try to put your bracket on the inner bracket of the Corolla throttle body will not allow it. So, you just have to cut/grind that inner bracket until your bracket will fit. The Tercel bracket has a little alignment nub on the back of it, grind it off/smooth too. Now put the bracket on and tighten the 12mm nut/lock washer up. Below is a pic of the stock tercel bracket (outer bracket) on the Corolla cut inner bracket.
Now, the fitment issue of the throttle body is that the idle air control valve will hit the EGR tube. So, first take the throttle body and situate it in as close as it will line up and you'll see the IAC hits the line. Mark where it hits. So what you do is, remove the EGR tube and modify it. Loosen the big nut holding the tube to the EGR valve with a monkey wrench. Undo the 12mm nuts on the tube on the intake manifold. Remove the tube. What I did, is beings as this tube is so strong, it is very hard to bend, and maintain it's mounting locations. So what I did was, at the point where the IAC hits it I just hammered the tube some making it an oval/flatter shape in that spot (remember, don't hammer too thin or it won't flow correctly). Now you just put it back on and see if it hits the IAC on the throttle body. Make sure you allow enough room for when the wiring connector will be hooked up. Then tighten it back up if it's good. It w ill be a very tight squeeze if not butt up against the EGR tube.
Now, you should be ready to put it back together. Make sure all the old gasket is off the intake manifold. Use the corolla gasket. Hook up the coolant lines. Get the 2 long Corolla throttle body bolts and send them throught the throttle body and through the gasket to line the gasket up. Get them threaded in and then send the 2 Tercel bolts through the bottom. If you can, torque the bolts to 14 ft/lbs. Reconnect wiring, vacuums, throttle cable and leave intake system off for now. And then fire it up! Check for coolant leaks, make sure your vacuums are right, and there you go. Corolla throttle body on a Tercel.