MJG55

So my 87 corvette's throttle body seems to be sticking and I have been looking around at replacements and have decided I want to go with a BBK 58mm TB

I've never upgraded a throttle body before so is it just a bolt on and drive operation or are there additional things I need to change for it to work correctly

billschroeder5842

Whoa up there.... (forgive me I'm from Texas)

Before you go out and spend you money on a new Throttle Body, have you tried to clean it? A lot of TB problems (Sticking, idle issue, acceleration) can be traced to a dirty TB.

Take your TB off and clean it or at a minimum try to do a "on car" cleaning.

Joe C

jv9999

That fancy new TB isn't going to buy you anything in performance. It's not the limiting factor by a long shot.

86Pacecar

I put a BBK on mine too when I had TB issues. Never performed or ran as well as the stock unit. See link for what I did. It is working great and working so muvh better than the BBK ever did.


https://www.corvetteforum.com/forums...ft-rebush.html

C409

..... Try some silicone spray lube ! ... about $3 a can .....

aklim

Buddy of mine did that with his new car or when it was new. Felt faster too. Unfortunately, at the track he consistently ran slower times with it. It has to function as part of a system not a stand alone thing.

Yes, it is bolt on. You have to take the top plate off, take the IAC off, take the coolant hoses off and take the IAC housing off. New gaskets obviously. That said, since you are there, why not clean the IAC passages, clean the TB butterflies and clean the IAC housing? Spray off the IAC pintle with brake cleaner and GENTLY wipe it (no pushing) and see if it works better. For all you know, you might have a bad cable.

hilflos

This is pretty much what I did with mine, which is also an '87. It was sticking at about 15% pedal travel. It's almost as if there was a notch, or a sticking point.

So, you'd build up enough force to get past the sticking point, and then, too much force, and you're instantly at 50% or more throttle. It made driving it in a civilized manner, difficult.

A thorough cleaning, pretty much exactly as aklim describes there solved the issue. The throttle's been nearly perfect for the last three or four months now.

mlm0

If for some reason cleaning it as stated in the other replies does not help, I would send it off to be rebuilt before I would replace it, It's also cheaper

DouglasC

ONE MORE THING : Going to a 58mm isn't the answer at all in my experience. The Stock unit is a good fit for a stock system. The 52mm will work fine but don't even consider the 58 unless you do some porting and a host of other MATCHED air flow re-mods. Clean the stock unit my friend & you'll be a happy and richer Vetter !!