CHOKE CABLE REPLACEMENT

[John McCormack]

I have just read some old threads on choke cable repair but unfortunately they didn't solve my problem.

 

The car is a 1970 CP PI RHD. The choke cable to the throttle fast idle has broken.

 

I have a new twin cable to put in but haven't been able to get the old cable out. I don't want to destroy the existing cable as the fuel enrichment cable to the MU is ok so starting the car isn't a problem, it is just a nuisance in traffic until the engine has warmed up enough to idle.

 

The broken cable is a repro one and the knob is moulded on, it doesn't have a hole to a button to release it. I have to take the nut off the back of the dash and pull the whole lot out the front of the dash. See attached photo for the type of knob/cable.

 

I cannot for the life of me see a way to get at the nut on the back to loosen it. It is on tight and is deeply recessed in the dash framework. Removing the radio won't help, it is the metal frame of the dash that is in the way. The ring on the cable at the front of the dash is also moulded and doesn't unscrew.

 

I am sure others have done this and there is must be a technique to get at the nut with something to loosen it. Once loose it will unscrew pretty easily.

 

Has anybody out there with a similar car developed a way to get at the choke cable nut?

[TR NIALL]

Remove the H Frame altogether you’ll have a lot more room to fiddle about.

[Mike C]

I normally get the 1/4 turn or so needed to loosen the nut with a flat spanner turned sideways.

 

Maybe you could cut a slot in a cheap tube spanner and turn it with vice grips to stop it expanding?

[John McCormack]

I ended up removing the H frame and the small piece at the bottom of the dash that it bolts onto. I could then get a flat spanner in between the two panels and get a one flat turn on the nut. I could then get a finger in and eventually got the nut off.

 

I should be able to fit the new cable ok, I just to get some strong line to tie onto the cable so I can mouse the new one through the tube the two cables run through.

 

When I took the cable off the MU the fuel enrichment lever dropped down a long way. I have put it back in position and it has the same spring tension, but will it be a problem that it rotated back a long way?

[Mike C]

Upon rereading my reply above is a bit ambiguous- I meant to say I used the top of the flat spanner to undo the nut, and the same to tighten it the 1/4 or so required for a tightly located cable position.

 

Don't know why the fuel enrichment lever would drop back, do you still have thirty thou or so clearance on the external MU enrichment cam ?

[John McCormack]

I finally did as others suggested. I removed the radio, A frame and its mounting bracket. I got a thin spanner onto the nut by going up between the main dash support bracket and the dash section with the knobs. I couldn't get this latter piece off, It came free on the passenger side opposite end to the choke but the choke end was held firm by something I couldn't find.

I got the nut moving, only about 1/8 of a flat but enough to luckily move it with a finger.

The new one went in but I can't get the nut on the back on properly. Access is very poor with this model and I suspect the thread has been slightly burred in installation. As I can't get a spanner on it it only goes on a thread or two by finger. I spent an hour or more trying to improve it without success.

However, it is tight in the hole and as it works with little friction on the inner cable it works fine. After a lot of time adjusting the MU and fast idle ends to get the right movement on each it starts and cold idles nicely.

Yesterday I could have sold the car cheaply I was so frustrated with it. After the choke repair I went for a short blast. Smooth, fast and a glorious howl, its price just doubled.

Edited July 2, 2018 by John McCormack