Replacing broken throttle cable
#16
Didn't say I was going to drive it until I come up with a solution or fix.
If it is not the cable then what could it be? The pedal movement has a course, slightly notchy feel to it. So I believe the problem is somewhere between the pedal and engine firewall. I greased the assembly connecting the pedal and the cable, that's not it. The Idle Control Valve doesn't really have any influence over RPMs over idle from what I understand so I doubt that is it.
If it is not the cable then what could it be? The pedal movement has a course, slightly notchy feel to it. So I believe the problem is somewhere between the pedal and engine firewall. I greased the assembly connecting the pedal and the cable, that's not it. The Idle Control Valve doesn't really have any influence over RPMs over idle from what I understand so I doubt that is it.
#17
Three Wheelin'
Didn't say I was going to drive it until I come up with a solution or fix.
If it is not the cable then what could it be? The pedal movement has a course, slightly notchy feel to it. So I believe the problem is somewhere between the pedal and engine firewall. I greased the assembly connecting the pedal and the cable, that's not it. The Idle Control Valve doesn't really have any influence over RPMs over idle from what I understand so I doubt that is it.
If it is not the cable then what could it be? The pedal movement has a course, slightly notchy feel to it. So I believe the problem is somewhere between the pedal and engine firewall. I greased the assembly connecting the pedal and the cable, that's not it. The Idle Control Valve doesn't really have any influence over RPMs over idle from what I understand so I doubt that is it.
In your case, I can't think of anything else it could be. Perhaps you could get under the car while someone else pushes on the pedal, listening closely to various points along its length. Try to prove the cable is sliding cleanly through its various tubes and connections.
#19
I got up very early and hit the empty highway home. I tied a strong string to the throttle linkage in the engine compartment and ran it up to the cabin so I could pull the throttle closed with my finger in case it got hung up at high RPM.
I kept the RPM under 2800 and it was much less of an issue coming home than yesterday, pulling the throttle closed with the string didn't seem to make a difference if the RPMs hung for a bit. Could it be the ICV after all? Would a vacuum leak behave this way?
Hitting the brakes and slowing down will cause the RPMs do drop, as it should, but if I take my foot off the pedal or take it out of gear, the RPMs will hang and then drop off, but not every time.
Thanks for the replies guys...
#20
Burning Brakes
Two thoughts come to my mind:
1. Check the engine compartment to make sure nothing is getting in the way of the throttle cable.
2. I didn't like the way my pedal felt so I started to adjust it to see if I could make it better. There are two adjustment points. One under the pedal (primary) and one where it comes out of the tube (secondary). When I went to adjust the secondary point I noticed something wrong. The secondary mechanism is a two piece plastic connector screw affair. You can tighten and loosen the cable by turning this. In my case the aft piece had broken off of the cable jacket. The result was that I could move the cable jacket in and out of the connector. This nullified the purpose of the connector/screw which is to keep the cable at a certain tautness. Without this my pedal felt sloppy and less responsive. Check that plastic connector for this condition.
Here is the bad news. I ordered a new throttle cable from Sunset in OR. I was lucky to get it as they said IT WAS THE LAST ONE IN GERMANY. Don't know if they are making more or not but be aware in case you need a new one as you might have trouble finding it (this is the one for the 95's: 99342302303).
Anyway here is a picture with the red arrow pointing to where it broke:
1. Check the engine compartment to make sure nothing is getting in the way of the throttle cable.
2. I didn't like the way my pedal felt so I started to adjust it to see if I could make it better. There are two adjustment points. One under the pedal (primary) and one where it comes out of the tube (secondary). When I went to adjust the secondary point I noticed something wrong. The secondary mechanism is a two piece plastic connector screw affair. You can tighten and loosen the cable by turning this. In my case the aft piece had broken off of the cable jacket. The result was that I could move the cable jacket in and out of the connector. This nullified the purpose of the connector/screw which is to keep the cable at a certain tautness. Without this my pedal felt sloppy and less responsive. Check that plastic connector for this condition.
Here is the bad news. I ordered a new throttle cable from Sunset in OR. I was lucky to get it as they said IT WAS THE LAST ONE IN GERMANY. Don't know if they are making more or not but be aware in case you need a new one as you might have trouble finding it (this is the one for the 95's: 99342302303).
Anyway here is a picture with the red arrow pointing to where it broke:
Last edited by Vorsicht; 08-09-2014 at 08:45 PM. Reason: Add part no.
#21
Vorsicht,
Thanks for the info. It may be a few days before I can crawl under the car and check everything.
If the cable is truly NLA I know there are plenty of shops that work on sandrails, motorcycles, etc, that could fabricate a replacement if needed. I may have to go that route.
Thanks for the info. It may be a few days before I can crawl under the car and check everything.
If the cable is truly NLA I know there are plenty of shops that work on sandrails, motorcycles, etc, that could fabricate a replacement if needed. I may have to go that route.
#22
Burning Brakes
I believe the Varioram version throttle cables are still available. I read somewhere on here that you can make that one work. I believe it is a little longer.
#23
Update
Well, I got under the car and the sheath that surrounds the cable just behind the plastic adjustment nut (near the tranny) has broken. As the cable moves fore/aft the sheath is butting up against the plastic nut and causing the cable to stick.
As mentioned Porsche is indeed currently out of stock of the part number I'm looking for (1995). Like many older parts they wait for a big enough demand and then produce (or have produced) a batch of them. Could be a week or a few months...
I called around to several independent Porsche garages here in town and found one that had the Genuine Porsche part on hand so I picked it up. Not looking forward to messing with that rubber bushing.
Edit: Took another look at the cable where the sheath is broken, the cable is frayed and hanging on by just a few strands. It was going to break very soon.
As mentioned Porsche is indeed currently out of stock of the part number I'm looking for (1995). Like many older parts they wait for a big enough demand and then produce (or have produced) a batch of them. Could be a week or a few months...
I called around to several independent Porsche garages here in town and found one that had the Genuine Porsche part on hand so I picked it up. Not looking forward to messing with that rubber bushing.
Edit: Took another look at the cable where the sheath is broken, the cable is frayed and hanging on by just a few strands. It was going to break very soon.
#24
Three Wheelin'
#25
I got the new throttle cable in, it was easier than I was expecting. On a '96 and later it would be a little more difficult. The rubber grommet was difficult but not too bad. I smeared vinyl and rubber dressing on the old grommet and the new one and that helped greatly. Pedal movement is very smooth now.
Some notes: If you have the old cable handy, fully tighten and loosen the plastic adjuster nuts so you have an idea how much play you have to work with. Counterclockwise takes up cable slack (backing out the threaded portion) and clockwise loosens. I put just a tiny dab of white lithium grease on the threads to make them move more freely and this does help.
Some notes: If you have the old cable handy, fully tighten and loosen the plastic adjuster nuts so you have an idea how much play you have to work with. Counterclockwise takes up cable slack (backing out the threaded portion) and clockwise loosens. I put just a tiny dab of white lithium grease on the threads to make them move more freely and this does help.
Last edited by KNS; 08-13-2014 at 10:12 AM. Reason: Vacuum fitting found...
#26
Rennlist Member
Two thoughts come to my mind:
1. Check the engine compartment to make sure nothing is getting in the way of the throttle cable.
2. I didn't like the way my pedal felt so I started to adjust it to see if I could make it better. There are two adjustment points. One under the pedal (primary) and one where it comes out of the tube (secondary). When I went to adjust the secondary point I noticed something wrong. The secondary mechanism is a two piece plastic connector screw affair. You can tighten and loosen the cable by turning this. In my case the aft piece had broken off of the cable jacket. The result was that I could move the cable jacket in and out of the connector. This nullified the purpose of the connector/screw which is to keep the cable at a certain tautness. Without this my pedal felt sloppy and less responsive. Check that plastic connector for this condition.
Here is the bad news. I ordered a new throttle cable from Sunset in OR. I was lucky to get it as they said IT WAS THE LAST ONE IN GERMANY. Don't know if they are making more or not but be aware in case you need a new one as you might have trouble finding it (this is the one for the 95's: 99342302303).
Anyway here is a picture with the red arrow pointing to where it broke:
1. Check the engine compartment to make sure nothing is getting in the way of the throttle cable.
2. I didn't like the way my pedal felt so I started to adjust it to see if I could make it better. There are two adjustment points. One under the pedal (primary) and one where it comes out of the tube (secondary). When I went to adjust the secondary point I noticed something wrong. The secondary mechanism is a two piece plastic connector screw affair. You can tighten and loosen the cable by turning this. In my case the aft piece had broken off of the cable jacket. The result was that I could move the cable jacket in and out of the connector. This nullified the purpose of the connector/screw which is to keep the cable at a certain tautness. Without this my pedal felt sloppy and less responsive. Check that plastic connector for this condition.
Here is the bad news. I ordered a new throttle cable from Sunset in OR. I was lucky to get it as they said IT WAS THE LAST ONE IN GERMANY. Don't know if they are making more or not but be aware in case you need a new one as you might have trouble finding it (this is the one for the 95's: 99342302303).
Anyway here is a picture with the red arrow pointing to where it broke:
#28
Rennlist Member
Seeing 10yo threads revived is always fun, but Ill take this opportunity to tell everyone with their original throttle cable that not only is it great preventative maintenance but you'll be amazed how much tighter the pedal will feel when you replace the old stretched cable. A must-do for any air cooled car.
The following users liked this post:
Enso (01-13-2024)
#29
Rennlist Member
As far as I know, and I've owned the car since 2001 @ 60k miles, and now the car has 151k miles, this cable has never been replaced! I don't think it's part of any annual service schedule, like replacing plugs, etc. a worthy thing to consider next time I go in for service.