Am I missing something (literally)? S3 throttle cable

[tileart]

Somehow when getting out of the car in a confined space (my garage) I managed to get my right foot somewhat stuck and dislodged the throttle cable at the pedal end. Ber!

By wedging the throttle open at the engine end, removing the steering wheel, and contorting my ageing frame into the footwell, I had enough slack to get the cable back in place. Surely this must be the worst god-awful bit of design ever? I’ve checked in The Bible and searched on PH, but most threads deal with snapped cables.

I'm a worse artist than I am mechanic, so on my "exploded" drawing am I missing something that should sort of pop over the top of the pedal end cutout, to stop the cable just pinging out?

[magpies]

Mine is an S1 and totally different to yours

Has a half cylinder with ball shaped hole which sits on a ball at top of the pedal and kept in place by a spring steel shape

[magpies]

By the way it is easy to snap the cable if no pedal stop fitted. TVR did not fit one.

[GreenV8S]

On my V8S, the throttle pedal has a keyhole slot and the cable inner passes through a ferrule which is a tight fit in the round part of the keyhole. I don't remember whether the V6 was similar. An inner without the ferrule would fit in the slot and be vaguely located, but would be very loose and easy to dislodge. What are the shape and dimensions of the slot in your throttle pedal?

[phillpot]

So all previous replies are grippingly interesting but sadly totally irrelevant because they're different engines


From your jolly good sketch I would say that is bang on for a 2.9 engined car


Micky "Magpies" is bang on with his suggestion of a throttle stop, Google " Pistonheads TVR S Series throttle stop" and various designs should appear, from excellent (mine) to okay-ish (I've got three or four minutes spare, I know, I'll make a throttle stop)

Edited by phillpot on Friday 20th July 19:58

[tileart]

Thanks chaps for your replies. So I’ll work on the basis that the pedal end is OK. But that raises a slight issue as to the other end. As assembled (before I started taking stuff apart), there was an apparently random bolt with locknuts that was just screwed all the way down, so it did nothing. I have reassembled it on the basis it’s some kind of limit stop to make sure the throttle can’t be opened up to the point where the engine thrashes itself to pieces? But since I don’t know what it’s called, I don’t know what to Google. That would also mean the throttle cable could in the extreme case of heavy-foot-itis be put under massive tension and lead to it snapping? Or is my reasoning completely rubbish, and as they used to say of my school homework about 60 years ago, “See me”…..

[mentall]

Mine (S3C) is just like yours, and your diagram is splendid. And it is an awful design.

However my 'cable end stop' is a cable nipple: a 25mm long tube with two grub-screws that grip the cable, since I replaced the cable with a Burton Power Sierra item (which didn't have the end on it).

The cable tension should stop the cable jumping out, but doesn't. My remedy is a pop-rivet with the pin taken out, slipped over the cable between the 'cable end stop' and the slot/hole in the rod. It fits perfectly in the hole and stops the cable from moving.


I've now replaced the sticky Burton cable with a much superior item - actually a NOS Boxer van clutch cable, cut short, with the other end also modified to fit the Ford bits. It has a nylon-coated inner cable which is braided rather than twisted steel, which runs in a separate PTFE sleeve which fits in the fat outer. I can't see why this shouldn't be done with any clutch cable that's long enough, but it did take half a day's engineering/bodging to make it work.

Incidentally for this sort of job: wheel off, seat out. I can do this in ten minutes, now!

But I can't turn the effing picture through 90 degrees!

[phillpot]

tileart said:

there was an apparently random bolt with locknuts that was just screwed all the way down, so it did nothing.

I'd say that is non standard..............




While it may act as some sort of throttle stop, being at the engine end it won't stop the cable being under excessive tension when you "floor it"

[mentall]

Mine is the same as yours at the engine end, but without the nuts and bolts you're holding, and with the benefit (?) of another concentric return spring on the cable itself.

My suspicion is that all this gubbins on the side of the plenum chamber is part of the kickdown system on the auto Granada/Scorpio and is otherwise unnecessary. Somebody on PH has a modification which leads the cable straight through to the cam plate: can anyone give me a link?

Many have written of the danger of breaking the cable without a stop; on mine the stop, at full travel, seems to be the floor. Anyway, my 'clutch' cable isn't going to break in a hurry.

[phillpot]

mentall said:

Somebody on PH has a modification which leads the cable straight through to the cam plate: can anyone give me a link?

This is mine .......... clicky cable
I think someone else is running theirs with out even the slotted plate, I tried it but found the response too fierce unless you're building a dragster!

[glenrobbo]

The throttle cable end on my S3c is the same as yours and regularly used to work its' way out of the slot in the top of the throttle pedal lever arm.
I simply pushed the cap from a cheap ballpoint pen over the end to retain the cable in the slot and it has been fine ever since. Simple.


I really must get round to fitting a throttle stop though.

[Oneball]

Minis and various other BL cars from the 60s and 70s have a similar throttle cable/pedal attachment. They have a spring steel clip that covers the slot to stop the cable coming out.

[tileart]

Thanks all for the very helpful suggestions. It's all back together again, and I'm sure the neighbours will thank me for not starting her up until the morning.

It's still a pretty horrifying thought that (just like those 4 little envelope-sized patches of rubber that keep us glued to the road), it's a rubbishy old bit of cable that transfers the thoughts from our brain, through our right foot, and to the engine.

Mind you I wouldn't fancy trying to fix any of the above on a rainy winter's night somewhere in the countryside -- don't smirk, in the (rather distant) past I have used TVR's as my daily drive.

[RayTVR]

phillpot said:

tileart said:

there was an apparently random bolt with locknuts that was just screwed all the way down, so it did nothing.

I'd say that is non standard..............




While it may act as some sort of throttle stop, being at the engine end it won't stop the cable being under excessive tension when you "floor it"

I can offer a different suggestion. When I got mine the cable didn't have the 'locator' on the end so had a similar bolting arrangement but with a fine hole drilled through the bolt. The bare end of the cable was then held by the double nuts. Although this would have shortened the pivot point, it did work fine.

I've since located an original throttle cable and am back to the proper fixing (with the metal spring clip) so not able to photo.

[tileart]

Mine had evidently been dismantled in the past and tinkered with, and there's no sign of that drilled bolt (which would be my expected way to make the connection). Good point about the pivot point, "mechanical advantage" and all that O-Level stuff. I recently refurbed some cleverly-designed folding garden chairs for my daughter, and just like TVR's, there seemed to be at least a dozen ways to put them back together, but just like TVR's only one of them was correct !