PI Choke mechanisum

[JustinF]

Hi Guys

I wonder if someone can help me. On my recently aquired 1972 CP TR6 the choke cable that runs to the cam on the throttle linkage was snapped of when I bought the car. As the weathers cooling down I have decided its time to get the choke sorted out to make starting easier. As new cables seem to be a rare as hens teeth at the moment (Moss & Rimmers said they are waiting stocks to come in from America). I have got Speedy Cables looking to see if they can repair my original cable.

My question is that when I got the car the spring and the link bar that connects the cam to the boby were missing. I have aquired a new return spring but the link bar part No. 149785 is listed as no longer stocked. Can someone tell me where on the bodywork it clips in, as I can't see any obvious attachment holes. Also would anyone be able to post a picture of it and what the overall length is and the diameter of the wire it is made from. Then I can make one up.

 

Justin

[Mike Collins]

Justin,

 

The wire hook is about six inches long and hooks through a hole in the chassis below the cable attach point. It's a simple length with a hook at each end, thinner than welding rod but that would make a replacement. Hard to photograph but you may be able to work it out from these.

 

If you're stuck for a double choke cable you could try a cable splitter and some control cable. I used a heater control at the panel end, single cable to a splitter and then two out to the throttle linkage and MU. Picture should show the splitter.

 

Unfortunately I can't upload the pictures, send me a PM with your email and I'll send them to you.

 

Mike.

[JustinF]

Mike

Thanks for the information re the position of the fixing hole and the wire link. I will have a good look over the weekend and try and make up a suitable link. I guess it will be made from a peace of old coat hanger. Probably a bit to thick but its the only small diameter steel I think I have to hand. The important thing is that it will do the job.

 

Also thanks for the information about the choke cable, if Speedy Cables can't come up trumps I'll give this method a try.

[YankeeTR5]

I've wondered about this for a while. Is the carb (north american) choke cable useable in PI? Are they the same or similiar enough? I'm a ways away from getting to this point, but looking at the advertisements from TRF (and others) I've thought that the two cable choke for the carb cars might work with a bit of trimming. The fact that the euro vendors are waiting on US supply seems to confirm this. Any thoughts on this from those in the know?

 

To be honest, I was really thinking of just sticking with the original's - but with new paint, new this & that, I figure I might be going all the way. That said, sometimes the new ain't like the old.....

[AndrewP]

Heres a pic of my PI choke. I started off by not having it connected (just the enrichment arm) but it never really started well when cold, so I had to make up the rod and ended up buying a small and long spring from my local hobby store (Its the spring that attaches the exhaust to the body on a nitro engine!). Works a treat and picks up the idle to around 1500-1800 RPM when the choke is on (as per the brown workshop manual).

 

Hope it helps

 

Pic:-

 

 

Andrew

[SteveB21]

Hi Justin / Mike

 

I know this topic is a bit old, but I have the same question as Justin, as I have a missing return spring link.

 

Did the coat hanger solution work OK and is 6 inches the right length or should it be shorter / longer?

 

Thanks

 

Steve

 

[MarkSeymour]

I'm looking also for this part as my car has the spring and a cable tie.

 

Could someone let us know the exact dimensions and post a pic so I can make one from a steel coat hanger ?

 

All the best

Mark

[SteveB21]

Mark

 

If you PM me your email I'll send you pictures. Mine is 14cm long and I actually got it from Revingtons, although I'm sure the coat hanger will do the job just fine, and cheaper.

 

Steve

[Peter Cobbold]

I cut off that cable ca 1980. I found its much easier to 'catch' the engine when starting with just the fuel enrichment. Peter

[marki]

Hi.

I agree with Peter, don't bother just use the throttle. Mine never had one when I got it and I don't intend bothering.

Cheers Mark

[Stevecross]

+1 for Peter's comment.

 

My '6 that I have had for 18 years had a broken cable but never fails to start as long as I have a gentle foot on the throttle.

 

That has got to be some of the charm of owning these things - "Sorrry, she's an old girl. You have go know how to start these you know"

 

I actually tracked down an original twin cable about 8 years ago but never bothered fitting it.

 

Steve

[peejay4A]

I'll be a dissenter. Heeling and toeing desperately to keep the engine running whilst approaching a busy T junction isn't my idea of the charm of an old car.

[barkerwilliams]

I'll dissent as well, can start car with right foot, drive outside garage, get out of car to close doors, car stalls!

 

Open air valve, car doesn't stall, when hot just revs OTT until air valve closed a little.

 

Fit a twin cable, life is just too short.

 

 

 

Alan

[rvwp]

Hi Guys,

 

Just bought a twin cable fron the TR Shop, no problem readily available, Rich

[cp25616]

Have to agree with Alan and Pete here. The cold start cam is there for a purpose, namely to keep the engine running at enough revs until the engine warms up enough so that its not needed. Yes the enrichment device on the MU will start the car (hopefully) but will not keep the cold engine running at the right revs and will probably stall. If you have one of the two cables fitted just to the enrichment device then you must have an electric garage door and/or always work on your car when the engine is warmed up.

Alan

[aardvark]

Morning all.

 

I've only got the cable to the enrichment lever. My car starts with a bit of peddle but is completely off the choke in around a minute (even in winter). Thats enough time to put your seat belt on and for SWMBO to get herself comfortable before starting off. Consequently, I don't feel like I'm missing out not having one but thats just my experience.

 

Cheers

 

Dave

[SteveB21]

Mark - pictures sent.

 

Cheers

 

Steve

[ShaunC]

Yes, fit twin cable, why worry about having to keep blipping the throttle when the engine is cold. It may not work as intended if you have excessive slop in all the linkages though.