tooter's manifold adventure...

[tooter]

Already ran into a snag...

The throttle body bore diameter of the Corolla throttle body is 55mm and not 51 mm. I'm still going to run it, and flared out the adapter with a Dremel and reblasted it to accept the larger diameter...



So my question for anyone here who knows... are all of the Corolla throttle bodies 55mm and not 51mm?

[CTScott]

Originally Posted by tooter

Already ran into a snag...

The throttle body bore diameter of the Corolla throttle body is 55mm and not 51 mm. I'm still going to run it, and flared out the adapter with a Dremel and reblasted it to accept the larger diameter...


So my question for anyone here who knows... are all of the Corolla throttle bodies 55mm and not 51mm?

On 1ZZ Corollas the butterfly is 55mm in diameter

[tooter]

It's on...



Now I need to make up an intake that will fit the larger bore.

Ediit: Just started it up... Jesus, the engine went nuts! The computer was all over the place wondering what to do. I just let it keep trying to figure out what the hell is going on hoping that it would learn the new idling parameters. It's still idling after about 10 minutes and is down to 900. And when you turn the lights on, it jumps up to 1,100. So it's going to need the idle screw turned down. Now I'm glad I chipped it out so that I don'n need to take off the throttle body.

Ran out of daylight, so I'm going to take it for a test run and call it a day.

Came back from the test run... plug and play my ass!

The 030 throttle body has every single one of the problems that have ever been described.

High idle
Hanging throttle position.
Erratic high rpms
Rough jerking back and forth between throttle and decel.

I was damn lucky just to make it back home in one piece. Almost hit a car in traffic. l let off the throttle expecting the car to slow down and it decides to do one of those sudden 3,000 rpm accelerations while wondering what to do.

Bottom line... runs liks shit.

[CrankyOldMan]

Where did you get 51mm from? I'm looking at my flange template and the mating bore diameter is 56mm. I'm thinking that the butterfly itself is 51?

[tooter]

Here's a comparison between the two bodies...



...and the intake I cobbled together to fit the larger one...

[tooter]

Originally Posted by CrankyOldMan

Where did you get 51mm from? I'm looking at my flange template and the mating bore diameter is 56mm. I'm thinking that the butterfly itself is 51?

Hey Cranky,

51mm is the bore of the Corolla intake manifold. My guess is that Toyota must have gone to a 55mm bore throttle body when they changed to the plastic manifolds.

The 55mm throttle body fits fine and there are no butterfly clearance issues because the perimeter of the bore is only 2mm smaller, but this is still an issue I need to resolve. There's plenty of space to flare the adaptor out to 55mm I already did a quickie on one with a Dremel.

Greg

[JustDidIt]

awesome update!

[dragoonmc]

that looks awesome!

[tk-421]

55mm sounds about right. I made this exact mod a couple of years ago and I've had zero problems. I do have a high idle, but there's nothing I can do about that, since the idle screw has some epoxy on top of it. Ah well.

That erratic behavior should go away after a couple of trips (at least it did in my case).

[Bluevitz-rs]

Mabey something got messed up on disassembly/re-assembly?

[suckerface]

Originally Posted by Bluevitz-rs

Mabey something got messed up on disassembly/re-assembly?

This. Astroman and myself aren't the only ones to have plug and play success. I'm guessing something went awry when you started the chip swap drilling and pulled the epoxy off the idle screw.

It took a good 10-15 min for my yaris to calm down at first, then a few minutes the next couple starts. Within a few days, it'd idle high for about 90 seconds when I first started the car. Drove it like that for about a year until the wreck. Didn't touch a thing on the TB except with some degreaser to clean it up.

Also ran it with an SRI. Regular tubing size, just used a section of silicone tubing as a makeshift adapter. I'll try to find you my pics if you want to compare.

[tooter]

Originally Posted by Bluevitz-rs

Mabey something got messed up on disassembly/re-assembly?

Nope. I was super careful having read what everyone else did. Even picked out the epoxy real careful. The idle screw underneath is absolutely pristine...




I'm going to give it a couple of cycles, just to see if anything gets better. I'm for sure going to swap out the chips to get rid of that really irritating delayed throttle notch between light throttle and decel. The chip behaves as if it was made to control the throttle for an automatic transmission as likely the majority of them were.

Funny, if the 030 was supposed to be the good one. Makes me wonder what an 031 was like?

[suckerface]

Might be a stupid question, but you confirmed on the part itself that's it's the proper part number?

[tooter]

Yes. The number is clearly printed on the chip. The throttle body itself is in excellent condition, and nothing on it had been buggered around with. I'm going to cycle it some more before I swap the chip, just to see if things get any better and I'm definitely going to turn the idle down!

[cali yaris]

No one listens to me. I sold at least five pre-swapped TB's and none of my customers had issues. Swap the chip.

[tooter]

Originally Posted by TOLMACH

Tooter, interesting projst.. thanks for the update

Quesition: you were able to re-use the pins that came with the original TB in your adaptor/new TB setup?

Thanks

Yes.
The holes are threaded to accept the stock studs.

[tooter]

Originally Posted by cali yaris

No one listens to me. I sold at least five pre-swapped TB's and none of my customers had issues. Swap the chip.

Got it, Garm.

[bladesmith6]

I swapped the chip on the tb I had and still had issues. The high idle finally came down a bit but when you let off the pedal to decel the car got kind of herky-jerky(bucked) I finally took it off because of that. You could feel that the acceleration was better though....