[CamaroCT]

Ive found out the problem! now I need advice on how I should fix it. My girlfriend rev'ed the motor for me while I watched the throttle, and the throttle spring is sticking. I guess the other throttle body I tryed was also defective. The throttle will go back most of the way, but I had to manually push it all the way back by hand, then the rpms dropped to a perfect idle.

So, am I able to buy a new spring and change it, or do I require a whole new throttle body. Is it possible to fix the spring I have now. Thanks!

Craig

 

[Everett#2390]

If you're talking about the coil spring wrapped around the throttle shaft to close the plates, I don't know if GM sells it separately or in a kit.

But, you could buy an external spring and cut it to length and hook it up externally.

You might see if the throttle plates are being pulled/closed not in a straight line as it should.

 

[JimM]

I might wonder about the throttle cable, and anything else attached to the throttle lever (cruise control & auto trans TV cable??) as a possible source of binding.

 

[CamaroCT]

I might wonder about the throttle cable, and anything else attached to the throttle lever (cruise control & auto trans TV cable??) as a possible source of binding.

I disconnected every cable from the throttle body to rule them out. I only have the one cable btw. I turned the lever by hand and let it release and it goes back 90% of the way after some lubing. And by hand if I push it that last 10% my car will drop to a perfect idle.

It was harder to get it to stick when I did it by hand, opposed to someone pressing the pedal. It seemed to stick 8/10 trys with the pedal, and about 5/10 trys by hand. Im thinking it could be a combination of both but moreless the spring.

 

[Eric Kammerer]

Have you given the TB a good cleaning? If there's a bunch of junk on the bore and the plates, they could be the source of the bind. The springs are just there to provide some tension to return a properly lubed and cleaned TB to the closed position. Unless the car is really high mileage or has really been beat on, I can't see the return spring loosing that much tension. If that was the case, there should be more than just yours, and there might be a TSB on the problem with a replacement part number.

If you use a good cleaner like GM Top Engine Cleaner and some q-tips and rags, plus a lot of patience and wiping until the q-tip or rag comes out clean, you'll be amazed at how much residue collects on the back of the plates and bottom of the bores on a TB car with EGR. You have to take the TB off, or at least get everything loose enough to turn it over to get at the underside. Spray in cleaners won't do as good a job.

 

[CamaroCT]

Last summer I took the TB right off and sprayed it down with TB cleaner, used a rag and got all around the plate, and sprayed in all the little ports.. gave it a good scrub.. i suppose I could take it off again and double check it.

 

[CamaroCT]

Ok I took another look at my throttle and Ive found something else out. With the motor off the throttle doesnt stick in the least, moves totally free. But once the car is turned on, then it will stick... Is this a vacuum leak? or possibly something wrong with the IAC. Ive changed the throttle body gasket and nothing. So close to an answer, can anyone think of what it might be? Thanks!

Craig

 

[Everett#2390]

The throttle plate shaft could be worn enough, or the plate itself, to allow the shaft to be out of alignment with engine upon it.

There should no play with the throttle shaft in the body/throttle plate, either at idle, part throttle, wide open throttle.

 

[CamaroCT]

So I guess this means I am looking at a new throttle body. I eventually want to do the 3.4L swap, and I heard I will need a Holley 400 CFM replacement throttle body. Im just wondering if this will fit my 2.8, this way I dont have to buy a replacement now, and another one down the road when I do the swap. Anyone know how much this Holley 400 TB costs?

Ive already tried another throttle body from the scrap yard and it worked the exact same as mine now.. maybe both TB's are defective or maybe there is another problem. Thanks!

Craig

 

[Everett#2390]

If staying EFI, the new TB won't be a problem, providing you don't see any external forces making the present problem.