sticky acc. pedal.

[vettewest]

My C4 has a problem with a sticky acc.It's not the pedal,I've pulled that to pieces and greased it.It's not the cable, I've oiled that.I'ts not the throttle body,I've had that bushed with teflon sleeves.The throttle is easy to open and does not bind when the motor is not running.However when the motor is running the throttle is very hard to open.Seems to be a vacuum problem to me.It has been suggested to me to drill a small hole in each of the butterflies to cut back on the vacuum.Has anybody got the same problem and has anybody found a way to fix this......gw.

[Chromie]

Is the pedal just as heavy with the engine off as it is with the engine running.
If it is the same it is not a vacuum problem
It is either the the throw of the accelerator pedal, the angle of the accelerator cable to the pedal or the cable. After you lubricated the cable was it easy to pull the cable when it was out of the vehicle?;38

[Cameron 77C3]

You had accidentally posted this in the babe's section.  Won't get much of a reply in there.;43

I've moved it here.  You should get someone chiming in soon.

OOPPS. Chromie was replying when I moved this.  Have you found it again Chromie?

Cam
Forum admin

[Cameron 77C3]

Originally posted by Chromie
Is the pedal just as heavy with the engine off as it is with the engine running.
If it is the same it is not a vacuum problem
It is either the the throw of the accelerator pedal, the angle of the accelerator cable to the pedal or the cable. After you lubricated the cable was it easy to pull the cable when it was out of the vehicle?;38

He says:-

" The throttle is easy to open and does not bind when the motor is not running. However when the motor is running the throttle is very hard to open."

Cam

[Cameron 77C3]

Was is it sticking before it was rebushed?  Supply as much as info as possible.  Why were the bushes replaced?

I would think twice about drilling any holes.


Cam

[Vette Obsessed]

Originally posted by Cameron 77C3
Was is it sticking before it was rebushed?  Supply as much as info as possible.  Why were the bushes replaced?

I would think twice about drilling any holes.


Cam

I wouldn't be drilling any holes.  I'd be fixing the vacuum issue (if that is the problem) before I started modifying things as a work around solution.

[87Z51]

"has been suggested to me to drill a small hole in each of the butterflies"

Say goodbye to your idle.

What model C4? Different setups across the years.
How is the movement past idle?
have you driven any other C4s?
Early models seem relatively stiff ,
 most mechanics comment on how hard my '87 is
(with new cable and TB)
Could rework to get better leverage but may run out of WOT travel

[Chromie]

I am going to take a guess here, but it is might be that the "MANUAL" idle position is incorrect. In other words the butterfly position in not correct. I recon his is fully closed instead of partly open.
I suggest the the manual throttle position be checked/reset and then the throttle position sensor be reset.
This should solve the problem.

[vettewest]

Thanks for the feedback everyone.The throttle has been sticky ever since I bought this thing.I pulled the pedal to bits because I thought that was the problem.I took the acc. cable out and oiled it because I thought that was the problem.I had the throttle body bushed because I thought the shaft was binding.After doing these I still have a sticky acc.With the motor off you can easily open the throttle by hand (at the throttle body).It all feels good.Start the motor and the throttle becomes very hard to open,even by hand at the throttle body.The butterflies are not binding in the body.This is not just an "off idle" problem.You can be driving along and put a little pressure on the "go fast" pedal and it wont budge,put a little more pressure on and it lets go with obvious results.Everybody thinks your driving like a ratbag.All I want is a smooth pedal.I'm not keen on modifying anything without proven results.Fear not I won't be drilling,bending,bashing without a good reason.Is this a common problem ? My car is an '86.Soon to be on the market if it keeps giving me dramas.Anyone looking for a cheap conv.....Just joking,I'm determined to sort this out.....gw.

[Chromie]

I think that what you need to do now is to compare your Corvette to someone else's and compare pedal assemblys (length and throw), cable drag, and throttle bodies. Both running and not running engines. This will confirm where the problem is and then comparing the other Corvette's parts to yours you will have a tangeable result of the exact problem. If it ends up being throttle body it will require adjustment using the Service Manual as this part of the throttle should never be touched (it does have an adjustment).

[coradict72]

Mate instead of guessing around
get in touch with Greg Morris an
absolute wizard on C4's he is the
best take ur beast to him
0418 440 131   your welcome

[VET-005]

I had a similar problem some time ago and found the overeall length of the cable to be too short, therfore making the cable kink. I found the problem to be even worse with the bonnet (hood) down as it was also pressing the cable between the engine and the hood and restricting its movement.
Sometimes the cable might feel smooth but the angle adds to pressure and makes it heavier to operate the throttle.
Make sure the cable has nice smooth bends  to the throttle body and no kinks and if it has any of these replace it and you may have to possibly make it longer so it does operate more smoothly.

[87Z51]

For pre '88 models
 use Holden HQ -WB throttle cable
 part # 9929775 approx $30 from Holden parts dept.

Has correct fitting for early type TBs and is long enough to route around engine bay with out kinking.