Jnelso

Anyone ever have throttle cable break on their C-2, mines not broken but throttle plate seems to stay open slightly causing a high idle. If I manipulate the gas pedal the idle will go down to correct rpms. Not sure if the cable is sticking or if its in the throttle body. And need to know if there is supposed to be any gap between the throttle lever and stop screw?

Hurdigurdiman

Check the cable behind the black square part. Mine was holding up as yours is, because one or two strands had broken on the other side of the black square plastic. I did replace the whole cable from that point to the next junction, by tying the old to new cable with string and feeding it over the engine, which solved my problem. Make sure that you seat the black plastic square guide back the correct way up. If you have it upside down your revs will idle about 1500 which is not good lol.

DBJoe996

No gap between the stop screw and throttle lever. For a quick check undo the throttle cable and see if the idle is correct. Often times, if the cable has been disconnected, it doesn't seat right in the black plastic fulcrum piece. Disconnect the throttle cable and give it a good hard tug, reconnect and see if the idle is correct.

Jnelso

Thanks for the feedback, I'll be looking into it this weekend and follow your suggestions.

charlieaf92

Is there tension on the cable when its in that position? If so, try what others suggested in making sure the cable isn't getting stuck. If not, I would suspect its related to the spring that is supposed to return the throttle body to the closed position.

Mike Murphy

I have the opposite problem - my throttle sticks shut. I've tried to use carb cleaner, and that seemed to work before, but I, too, have a gap between the screw and the stop, and I want to adjust it, but the screw is torn up. I'm looking for a replacement screw.

DBJoe996

I would pull the entire TB and give it a good cleaning with TB cleaner. A lot of stuff builds up on the back side of the TB as well. Once it is off, you can manually move the TB open and close to see if there is any binding of the shaft bearings. Might as well give the ICV a good cleaning also.

It is my understanding that the "stop screw" is non-adjustable and is factory set. Remember, idle is controlled by the idle control valve, which is controlled by the DME/ECU. If you mess with the stop screw you might have a difficult time getting things back to normal. If you remove the stop screw I would take very careful measurements of the top and bottom set of the screw in the housing. I've heard the set screw is a real bear to remove and I would definitely use locktite when reinstalling.

Kris Murphy

OP, two things to check.

1. Have you removed the throttle cable from the throttle body? If so, it is possible to install the black grommet upside down.

2. Check the connection under the car on the drivers side by the trans. There is a junction there that is just held on with a brittle plastic clip. Check to make sure that is in the correct place.

I had both of these issues cause a similar problem when I put my new motor in.

Mike Murphy

Only thing I don't understand with the stop screw is: what prevents the butterfly from closing so completely that it wedges itself against the walls of the TB? The gap between the stop screw, I would think, would solve that purpose? If I abruptly lift my foot off the throttle, the butterfly slams shut and get wedged in, presumably by buildup like you said, but it also appears as though the valve will wedge in regardless unless the stop screw prevents it?

Jnelso

Disconnected throttle cable at throttle body as suggested and the butterfly went right to the stop. Went under the car to the connector for frt and rear cable, separated the connector and found a bit of debris in the connector apparently causing the cable to hang up a bit. Cleaned the connector and housing, everything works fine now. Probably will replace the rear cable as preventative maintenance issue.
Ran a DE in the rain couple weeks ago and notice a lot of sand on the underbody from the rainy track, might have contributed to the debris in the cable.

Porschetech3

You pretty much got it figured out. The throttle stop screw is to keep the butterfly from sticking on the bore, and to set the minimum idle speed. The throttle shaft barrel lever should touch the stop screw at idle before the butterfly touches the bore.

Clean the throttle body and idle control solenoid. To adjust throttle stop screw, disconnect idle control solenoid and adjust minimum idle speed to 650-675 warm engine A/C off. Then reconnect idle speed control.

Jeff95M030

OK, so folks on this thread have some expertise that might be useful for my question. I have a 1999 track only car (PCA Spec 996 class) and there's a lot of slack in the throttle cable at the throttle body. My concern is that I may not be getting to wide open throttle when the go pedal is mashed to the floor. I don't see a way to make an adjustment at the throttle body end. Is there a way to tighten the cable at the pedal end or should I just assume the cable is stretched and put in a replacement OEM one? Sorry about the hijack...

Noz1974

Jeff yes there is, don't mess around with anything on the throttle body on the cable cars it's all factory pre set, if you jack the car up and put it on stands, get under end if you look on the left side of the body you should see the throttle cable coming from the engine bay down the side of the gearbox , there is a black plastic adjuster, I think you just pull it both ends and there's like a ratchet system inside , if you go too far you can twist it and shorten it again, have a play around with it you'll see what I mean it's a tension adjusting device just what you are looking for, funny I looked at the throttle body first too it seems logical then found that by accident re connecting my gear linkage on the gearbox!

Jeff95M030

Noz - Just what I needed to know. I'll get under there and take a look this weekend. Thanks.

Noz1974

No probs just be careful don't force anything it's plastic at the end of the day but once you figure it out you should be able to take up the slack just fine good luck