Author Topic: Choke  (Read 5830 times)

Offline PMD1969

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Choke
« on: November 26, 2012, 03:07:29 PM »
I have a QJet that has not run right in years.  At the moment I just need to limp it along until I can order Cliff's parts and rebuild it.

The symptoms are that the choke is not working.  I recently replaced the choke thermostat and that is working.  The carb adn choke are all original and the carb was rebuilt in 1995.  What is happening is that the primary flap stays closed unless I manually work the carb by hand.  I had temporary solved the problem by removing the primary flap but that keeps the secondaries from opening.

I can provide a picture if necessary.

Looking forward to getting this fixed to so that this OHC will finally wake up and run.

Appreciate the help.

Offline Shark Racer

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Re: Choke
« Reply #1 on: November 26, 2012, 04:09:52 PM »
What is the part # on the carb? Is it a hot air, electric or divorced(on manifold) choke?

I'm not familiar with tweaking the divorced choke setups. The carb-mounted choke could be adjusted too tight, or the thermostat could have been installed backwards so that it starts open and closes as it warms up.(may apply to divorced chokes as well).

It's a pretty simple mechanism, really.

Offline PMD1969

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Re: Choke
« Reply #2 on: November 27, 2012, 08:24:42 AM »
What is the part # on the carb? Is it a hot air, electric or divorced(on manifold) choke?

I'm not familiar with tweaking the divorced choke setups. The carb-mounted choke could be adjusted too tight, or the thermostat could have been installed backwards so that it starts open and closes as it warms up.(may apply to divorced chokes as well).

It's a pretty simple mechanism, really.

7029261  I am sure that it is simple for someone with experience but I have never really worked on it.  The divorce choke is good.  I know that the choke mechanism is way out but I have no idea how to adjust it?  I may put the primary flap back in, disconnect the choke and just resolve to flooring it when its cold.

Offline PMD1969

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Re: Choke
« Reply #3 on: November 27, 2012, 11:40:48 AM »
Here is an older picture


Offline Shark Racer

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Re: Choke
« Reply #4 on: November 27, 2012, 07:02:04 PM »
I meant no disrespect when I said it was simple - that was in reference to the on-carb choke. In the case of the divorced choke... I'm clueless. :)

Offline PMD1969

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Re: Choke
« Reply #5 on: November 27, 2012, 08:17:23 PM »
I meant no disrespect when I said it was simple - that was in reference to the on-carb choke. In the case of the divorced choke... I'm clueless. :)
LOL  No worries.  I just need Cliff to chime in and help me solve this terrible problem.  My mother is coming to visit and this car needs to be running better when she gets here.  No pressure lol.

Offline Cliff Ruggles

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Re: Choke
« Reply #6 on: November 28, 2012, 04:41:19 AM »
The divorced choke simply pushes the choke linkage up to close the flap when the engine is cold.  When the coil heats up, it pulls down on the choke linkage and allows the flap to open.  There is some adjustment by bending the link between the divorced choke and the carburetor. 

The picture shows a pretty steep angle between the choke coil and the carburetor, in most cases the choke is directly under the carb.  Could be binding up when applied.  I'd check choke function with the link unhooked, then verify it can move it's full range of motion with the link hooked up.

Also verify that the coil is working in the right direction cold and when it's heated up.  Also a bit old school, and some bending of parts is required for adjustments, those types of chokes work flawlessly when correctly adjusted....Cliff

Offline PMD1969

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Re: Choke
« Reply #7 on: November 28, 2012, 01:48:54 PM »
The divorced choke simply pushes the choke linkage up to close the flap when the engine is cold.  When the coil heats up, it pulls down on the choke linkage and allows the flap to open.  There is some adjustment by bending the link between the divorced choke and the carburetor. 

The picture shows a pretty steep angle between the choke coil and the carburetor, in most cases the choke is directly under the carb.  Could be binding up when applied.  I'd check choke function with the link unhooked, then verify it can move it's full range of motion with the link hooked up.

Also verify that the coil is working in the right direction cold and when it's heated up.  Also a bit old school, and some bending of parts is required for adjustments, those types of chokes work flawlessly when correctly adjusted....Cliff

Thanks for the reply.

The divorce stat is working and in the place where the factory installed it.  The problem seems to be that the carb needs AIR since when I take the flap off it starts much better.  Again the problem then is that the secondaries won't open.  I am not sure if there is an adjustment that I can make to get more air to the carb overall that will help and need I can install the flap and get the secondaries working.

Offline Shark Racer

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Re: Choke
« Reply #8 on: November 28, 2012, 05:13:00 PM »
Have you tested your choke pull off to be functional? The choke pull-off should open the choke as the engine turns over as it applies vacuum and pulls the flaps open a bit. There is an adjustment on the pull-off if it is tested to be functional.

Start by applying a vacuum to the pull off - it should hold vacuum and the pull-off will retract and open the choke flap when the engine is cold.

Offline Shark Racer

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Re: Choke
« Reply #9 on: November 28, 2012, 05:13:31 PM »
By cold, I mean the choke is cold (and set) and the engine is off.

Offline PMD1969

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Re: Choke
« Reply #10 on: November 28, 2012, 09:36:18 PM »
Have you tested your choke pull off to be functional? The choke pull-off should open the choke as the engine turns over as it applies vacuum and pulls the flaps open a bit. There is an adjustment on the pull-off if it is tested to be functional.

Start by applying a vacuum to the pull off - it should hold vacuum and the pull-off will retract and open the choke flap when the engine is cold.

Some updates.  I used a MityVac to test the pull off.  It works well but the little hose was questionable so I replaced the hose.  I replaced the primary flap and started the car.  It ran like crap (same as before) and would not run unless in WOT.  As usual it would not run unless it started getting warm.  After it got warm I adjusted the little screw that is close to the choke pull off and the more that I turned the screw the faster the idle went up.

Offline PMD1969

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Re: Choke
« Reply #11 on: November 29, 2012, 07:11:26 AM »
more updates.

I have replaced all of the hoses to the carb and adjusted (bent) the arm that should hold the primary air flap open more.  It seems that the carb is flooding it self out in " choke mode " but when that immediate problem stops it starts to want to run right.  I backed the screw out at he choke pull off and got it down to a decent idle 800rpm.  Now that its warm I'll wait until is cools to tr another choke start.

ETA:   :o :o :o  All of the mounting bolts on the carb were loose !  The idle stop bracket wiggled when I went to adjust the stop so I started checking all of them.  Geez - I took a 1/2 wrench and genty tightened them all down.   :o :o :o :o

Offline Cliff Ruggles

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Re: Choke
« Reply #12 on: December 02, 2012, 04:28:13 AM »
Adjust the choke pull-off so the flap is open to the correct angle on cold starts.

Remove the secondary lock-out and roll pin from the airhorn.  For some reason it is keeping the flaps closed, I can see it in the pic and the choke appears to be off.....Cliff