I got bored and curious today so as I decided to take the area around the butterfly up to 65-66mm. This is a guess because I didn't have a good way to measure it, but there is now a significant gap around the throttle plate.

The result: idle jumps from 1000-2500rpm even after trying various things to fix it. Part throttle crusing feels like when someone is just learning to drive and they dump the clutch without enough gas, very jerky. When I let off the throttle the rpms hang for a half second before falling, and the car seems to drive itself around town without any throttle.

I think this is a safe mod to do if you are only going up to say 62 mm. Above that the line where the IACV can compensate vs. where it can't seems to be very thin. I do not recommend going this large to anyone without getting a new butterfly.

I am going to order a type R butterfly tomorrow. I believe they are 62mm, so there will still be a small gap but, but I think it may be minimal enough that the IACV could once again compensate. The smaller gap didn't cause any problems yesterday, but now that it is larger I am getting problems. I will post the result in a week or so once the part shows up.

 

good luck...this is exactly why I never recommend boring out a throttle body.

I'm interested to know if the R throttle plate will work.

 

Sorry to hear the probs although I think I might have benefitted by ur actions. I have the SAME problem but my car is stock. The dealership said the throttle plate is bent (they claimed it was the nitrous... don't ask me how they guessed it was in there). I think I might have tightened the cable too tight and caused it to bend off axis. I got a new TB so I'm gonna try that out.

 

Man, that's way too funny.
I bore Throttle bodies as a side job, and the thought of doing it with a dremmel
just makes me giggle.
Of course you are going to idle like ****!
Of course you are going to have trouble driving the car.
Now here is the kicker.
Honda/acura will not sell you just the butterfly!
you have to buy the whole thing. $500 last time I checked.

I can fix it for you, bore the throttle body perfectly cylindrical and cut you a new butterfly that FITS the new bore size.
If you care to have it fixed, drop me a line.

here is a picture of a TB I bored.
I put the original butterfly over the new one to see how much bigger it is.


Good luck!


[Modified by Spaceballs the lunch box, 7:36 PM 6/22/2002]

 

What do you charge for the TB job?

 

I am pretty sure you are supposed to get a matching butterfly when you bore it out... You have a useless throttle body unless you pay to fix it...good luck

 

yep honda/acura wont sell anything off the throttle body
i tried to get a TPS sensor
hah 500$ for a new TB.
********...

 

What do you charge for the TB job?

I charge $125 including shipping back to you.
Whenever I do a TB over bore, I request to have to whole thing sent to me, complete with sensors.
I remove the TP sensor and put it back set to factory specs.
I microblast the whole Tb to like new condition, and taper AND polish the TB
opening. Just like the Spoon TB.
That way it's a bolt in mod.

 

do you spin them on a lathe?


Rob

 

No, I bore them on a Milling machine.
Lathes are much more tricky to get the TB to spin perfectly concentrical.
On a milling machine, I can compensate for the offcenter bore the Tb comes
from the factory. By offcenter I mean something like 15 to 20 thousands, which is a lot when you are trying to make it perfectly concentric.

 

i see, thats cool. So with the milling machine the peice (tb) stays still and the bit moves right? oppisite a lathe...


Rob

 

where is winter park
i am up in pensacola and want to have some head work.. some polishing , boreing, porting.. and maybe resleeving.. done

how far and how much of this can you help me with???

mkteller8@aol.com

plz email

 

Man thats some nice work, i might have to give you a ring,

 

yah looks like good work. I'm in FL too so I might have to hit you up. My friend would definitely be interested as well since he's going n/a. I'll let him know.

 

Does IACV stand for:

Injected Air Constant Velocity

?

 

i believe it is idle air control valve

 

...haha sweet, DIY Throttle body, sounds pretty ghetto !

 

I did the exact same thing, and had the same problem. It turned out to be a combo of two problems, which i am not sure you are aware of.

First, I took off the Throttle position Sensor (TPS) as to not damage it... it appears you did the same from your picture. This sensor is VERY sensative. It requires that it is very tight so no air is allowed to leak. If so, the check engine light comes on and it is very jerky.

Second, when I bored the throttle body (w/ a dremel) it was not perfectly even, not allowing the butterfly to shut all the way. I was confused because it appeard to be shut all the way, but it wasnt. You can test this by putting the TB on and leaving off the filter. With the car running, physically stick your finger on the Butterfly and push it shut. I woulnt be surprised if your idle went back to normal. To fix the problem, locate the screw below the Throttle pully, and loosen it slightly. This will allow the butterfly to close farther. Do not go too loose or it will kinda stick.

Anyways, there is nothing wrong w/ boring your TB, it just doesnt seem to do much, and it always seems to be a hastle. If you are a dork like me, its fun to waste your time smoothing every corner, and polishing every surface

-Jake

 

Yeah, it confused the hell out of me what was wrong with your throttle-body... glad its working OK now.