accelerator cable problem?

[carl74344]

just bought a 1982 sc some one put a new cable on.it idles at 2000. where the cable connects in the motor compartment i can move the cable and the idle goes up and down. i tried the idle screw but no change. thanks first porsche excited to fix it up.. carl

[twistoffat]

Is the throttle cable sticking somewhere?

[timmy2]

High idle may be a vacuum leak as well. If you disconnect the cable does the idle come down?
Post a picture of the cable attachment.

[chris_seven]

Cable? Has the rod system been replaced?

[Jim Sims]

The accelerator is a rod and linkage system - no cable. The clutch has a cable system. What may have occurred is a new clutch cable was installed and improperly routed (perhaps even wrapped around the throttle linkage rod). The problem is usually at the front near the pedal cluster. The solution is to reroute the clutch cable properly.

[carl74344]

the cable with red arrow. i can move the cable in and out and the idle changes. thanks for the help carl

i got the bentley manual today. can not find anything about that cable. i just about have everything for a tune up. i want to replace all the vacum lines. the car seems to run well just idles to high. when i get the idle right i will know how well it runs. high idle can hide problems..i really want to learn this car...carl

[Dave at Pelican Parts]

Cruise control cable. The cruise control unit is in the left-front corner of the engine bay. Maybe the bracket is loose?

--DD

[Nickshu]

The thing you have circled is the cable for the cruise control. The throttle (accelerator pedal) has a metal rod linkage with several pivot points and bushings along the way.

Take a look at the throttle on the engine (just forward of your cruise cable). See if it is all the way closed at rest. There is a microswitch on it (obvious) that is activated when the throttle is completely closed. You can pop off the throttle linkage (it's a ball-socket setup) with a screwdriver and see if it's holding the throttle open.

[carl74344]

thanks i will look at that. does the throttle run to a pivot point on the trans.? i saw that some where. if i get the idle right with the linkage off then i just back track the linkage to the accelerator pedal? where are the adjustments at? the pedal? thanks ...carl... the car is in fair shape 36,000 miles just not careed for right....

[timmy2]

The linkage attached to the throttle body is adjustable with small wrenches. Once you pop it off you will see a jam nut at each end. It is mounted to a pivot on top of the engine that is driven by linkage attached to the tranny, driven by linkage going to the front of the car.
There are plastic bushings that can wear out. I replaced mine with brass ones.
Download the PET parts catalog and take a good look at the drawings.
Porsche Classic Original Parts Catalogue - Classic Genuine Parts & Literature - Porsche Classic - Dr. Ing. h.c. F. Porsche AG

[carl74344]

the cruse control was holding the throttle open i adjusted it and the idle is now 975-1000 or so. now it goes up and down 100-300 rpms do not know if that is normal. does not seem right. i wiggled all the hoses nothing changed.. my plans are to adjust the valves , plugs wires, rotor ect. what else does the care and feeding of 911 take. also going to change trans axle oil and motor oil -filter. i think i love the car already.... i built street rods, vws but this was my dream car..i want to do the work myself....carl thanks to everyone--- always go to the ones who know....

[Dave at Pelican Parts]

The "hunting" idle could be an air leak (vacuum leak) letting "false air" into the intake, making the mixture a bit lean.

--DD

[carl74344]

yes i think that might be right. what are the symtons of a blown air box? or is it a smaller leak? im goiming to replace all the o rings on the injectors. i am going to do the vales adj. ,plugs ect... then start looking for the air leaks, is this the right way to start? your site has been great help. thanks ...carl

[Dave at Pelican Parts]

I don't know, it could be just about anywhere downstream of the air metering plate. I'm just about at the end of my knowledge on CIS, now. For the most part, we pay a pro mechanic to deal with issues on my wife's 82 SC.

--DD

[carl74344]

Dave , thanks for your help. i bought this car to work on and drive. half the fun is solving these problems. it was built once it can be fixed. i will learn more as i go. having a place with people who love their cars and do not mind sharing what they learn as i will share as i learn is a great place. again thanks....carl

[Walt Fricke]

Carl - one way to hunt down an vacuum leak is to use your propane torch. Remove the tip, and slip a couple of feet of tubing over the torch's pipe where the tip attaches.

With the motor at idle, stick the end of the tube in at various likely sources of leaks around your intake system, and crack the torch open so propane comes out the end of the tube. When you find an area where doing this causes the idle to increase, you have started to zero in on a leak.

Obviously you don't want to overdo this, but this is more controlled than spraying carb cleaner around, which is another method of checking.

[carl74344]

walt, that sounds like a lot cleaner way of doing it. i will give it a shot. thanks....carl