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-   -   '85 GSL: Can't pull out choke. *Period.* (https://www.rx7club.com/1st-generation-specific-1979-1985-18/85-gsl-cant-pull-out-choke-%2Aperiod-%2A-1127258/)

demongo 06-14-18 12:41 PM

'85 GSL: Can't pull out choke. *Period.*
 
'85 GSL FB 12A, manual transmission, automatic choke.

Very perplexing and frustrating. With the car completely off, no key in ignition, the choke knob won't budge--stuck solid in the "return" position.

Not sure if this is a magnet problem or vacuum problem; I've been hesitant to dig into it to this point, but now I need to get it smogged (I'm in CA) and I've no intention of not driving it.

Anyone see this before?

t_g_farrell 06-14-18 03:03 PM

It is probably in the choke switch. It may be corroded such that you can't get it out. Was the car ever wet or flooded? I can't imagine how that would happen otherwise. Theres no cable for this, so it can't be a rusty frozen cable like a throttle cable. Do you need the choke to pass?

NCross 06-14-18 03:41 PM

Find the choke linkage on the carburetor and see if you can move it by hand. If yes, then your choke is ok. If the knob still does not pull out then you have a binding cable or binding knob. They’re they same part so you will then need a choke knob assembly. You can try removing and spraying lube in the knob and cable sheath.

demongo 06-14-18 07:33 PM

Thanks for the ideas.

Now I have another question/problem: How do I get the trim piece off with the choke knob/mirror controls/rear latch/gas door button ?

I finally found all the screws and physical attachment points...but the wiring harnesses for the various switches are so short I can't pull out the trim and reach the choke switch.

How does one remove/replace the choke switch? It seems completely inaccessible without removing the dashboard....

tommyeflight89 06-14-18 08:23 PM

To remove the choke magnet/knob assembly it is easy.

There is a small philips (set) screw holding the knob to the shaft. Take that off,

Unscrew the tiny threaded ring behind it.

The unit will slide out by pushing it forward and grabbing it from below the dash/trim. Disconnect harness to choke/check relay.

There are small screws to take the cover off to see whats wrong.

t_g_farrell 06-14-18 09:21 PM

My bad, there is a cable. It could be frozen. You may need to pull it and free it up.

SKYDRIFTER350 06-15-18 02:41 PM

try one of those motorcycle cable lube devices...cost $10 at a motorbike shop... will lube just about any cable/sheath thingy...

tommyeflight89 06-15-18 05:29 PM

If that knob won't move with the ignition off I think it has to be the mechanism in the switch/magnet.

The choke knob doesn't pull on the cable directly, it pulls on a magnet that pulls on the cable. I think.

t_g_farrell 06-18-18 07:42 AM

The magnet sits around the knob and holds it out until it loses power when the temp switch on the waterpump houising opens and break the circuit.

demongo 07-03-18 11:55 AM

Thank you for all the responses; they were very helpful.
I've resolved the problem...but it wasn't quite the big mystery I thought.
It's an object lesson in problem investigation and resolution: *always* eliminate the most obvious/easily fixed potential causes first.

The problem ended up being a frozen choke cable; the spring at the carburetor had been stuck and wouldn't budge despite my pulls on the choke knob....
Couple spritzes Liquid wrench on the spring: freed.

Unfortunately I only found this out after dismantling the trim panels underneath the left side of the dash, breaking the vent vanes on the left dash vent and pulling/dismantling the choke magnet/knob (which in itself was a ridiculous chore).

When I couldn't find anything wrong with the actual mechanism, it was only *then* I fully investigate possible problems at the cable itself.

So the lesson here is: Check the easiest and most obvious areas first before assuming that it *must* be something more complicated....

:cursing::wallbash:

GSLSEforme 07-03-18 12:18 PM

"kiss"

Ben. 07-05-18 12:59 PM

Choke Cable
 
I had to deal with a similar issue recently. The choke was very difficult to pull out. If the cable is hard to pull, don't force it because that is likely to damage it for sure. In the end, the problem was on the carb side, not the choke cable side. In hindsight, the place to start the troubleshooting would have been when I disconnected the choke cable from the carb...it moved as it should...nice and smooth & easy. Therefore, not the cable. The binding was in the carb. These cables are pretty much resistance free when working properly, so if there is more resistance than normal, then isolate the problem by disconnecting the cable at the carb, and quickly determine if the cable or the carb is the issue.

During this adventure, I also found out about how to test the electric magnetic hold function of the choke cable with a multi-meter (from the fsm), which can also be especially handy before buying one at a salvage yard. The difficult part there is that you have to get to the electrical connection which is buried behind the dash, so you pretty much have to remove the cable from the dash and drop it down to do the test. This system also uses a temp sensor that is under the hood to provide a signal that the engine had warmed to a certain temp (? 158 degrees?, I think). I have removed a couple of these choke cables from salvage yard vehicles, and it can be challenging to get them out in the restricted space for my hand(s) under the dash, plus I couldn't see what I was doing very well... and working upside down part of the time. So, for me, I want to determine it has for sure failed before I have to go down that path. I decided to test, remove, and buy a couple of these at the salvage yard because they can be a bit costly (two on EBay today, $35 used; $85 new). Got them for like $15 each at the salvage yard, and both were smooth & easy, and passed the multi-meter test.

demongo 07-06-18 11:31 AM

Ben: Awesome response, and advice I wish I had taken. :icon_tup:


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